JP2007329641A - Frequency bandwidth switching amplifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frequency bandwidth switching amplifier which is variable in frequency bandwidth, and has a constant element value and occurs no distortion even when a large RF signal is inputted. <P>SOLUTION: The frequency bandwidth switching amplifier is provided with an input matching network 100, an FET 200, and an output matching network 300. At least one of the input matching network 100 and output matching network 300 has first and second cascaded high-pass filter networks 10 and 20, which include capacitors 11 and 21 connected to a signal line in series and inductors 13 and 23 connected to the signal line in parallel. The first high-pass filter network 10 further includes a first switch 12 connected to the capacitor 11 in parallel and the second high-pass filter network 20 further includes a second switch 22 connected between the signal line and inductor 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a frequency / bandwidth switching amplifier that can change the frequency bandwidth and does not distort even when a large RF signal is input.

  In order to use a plurality of communication systems such as wireless LAN, WCDMA, and BlueTooth with a single portable terminal, the high-frequency analog circuit (for example, amplifier) for the terminal operates at the frequency (high frequency) of each communication system. It is requested. At present, a single mobile terminal is operated for each communication system by switching a plurality of amplifiers having different operating frequencies with a switch or the like. However, when the number of communication systems increases, the number of required amplifiers also increases, and there is a disadvantage that the overall size increases. In order to solve this drawback, it is conceivable to use one wideband amplifier as an amplifier operating at a plurality of frequencies. In terms of the area occupied by the amplifier in the terminal device, it is preferable to use one wideband amplifier rather than using a plurality of narrowband amplifiers having different frequencies.

  However, when a jamming wave is input within the band, the wideband amplifier amplifies the jamming wave together with a signal of a desired communication system, and thus has a disadvantage of adversely affecting the use of the communication system. In order to cope with the above drawbacks, there has been proposed a frequency switching amplifier that changes an operating frequency by changing on / off switching or capacitance of a switch or a varactor diode provided in a matching circuit in a single amplifier. These amplifiers generally have a narrow band, and the number of switches and the like increases because the matching circuit is switched by a switch in accordance with the number of communication systems to be used (number of frequencies). This leads to an increase in loss due to the switch, and there is a problem that the efficiency of the amplifier is reduced and the size is increased.

  In order to achieve both improvement in communication interference resistance and downsizing of the device, an amplifier that switches the operating frequency and switches the frequency and bandwidth capable of making the operating bandwidth wide or narrow. Is required. When using a highly important communication system, it is preferable to use a narrow band characteristic in order to reduce the influence of an interference wave, and when using another communication system, use a wide band characteristic.

  A conventional frequency switching amplifier will be described with reference to the drawings. FIG. 15 is a diagram showing a configuration of a conventional frequency switching amplifier (see, for example, Patent Document 1).

  As shown in FIG. 15, a conventional frequency switching amplifier includes a transistor (amplifier circuit), an input matching circuit (input matching circuit), an output matching circuit (output matching circuit), a band (frequency) switching signal generation circuit, and a band ( Frequency) display section. The output matching circuit has a variable capacitor and variable inductor.

  The band (frequency) switching signal generation circuit receives a part of the output signal of the transistor, and switches one or both of the two output signals (lines) on / off according to the frequency. As a result, the two pin diodes are turned on / off, and the three capacitors connected in parallel in the matching circuit (two of the three capacitors are connected in series to the two pin diodes). The composite capacity changes. As a result, the operating frequency of the amplifier is switched.

  Another conventional frequency switching amplifier will be described with reference to the drawings. FIG. 16 is a diagram showing the configuration of another conventional frequency switching amplifier (see, for example, Patent Document 2).

  As shown in FIG. 16, in an output matching circuit of another conventional frequency switching amplifier, a variable capacitance diode connected in series is connected to a capacitor connected in parallel to the signal line of the output matching circuit, and a resistor is interposed. Connected to the power source. In addition, a variable capacitance diode is connected in parallel to the inductor of the signal line of the output matching circuit, and is connected to the power supply via a resistor.

  In the output matching circuit of another conventional frequency switching amplifier, the capacitance of the variable capacitance diode D1 is adjusted to vary the capacitance value of the matching circuit, and the capacitance of the variable capacitance diode D2 is adjusted to vary the inductance of the matching circuit. Thus, variable frequency is realized.

JP-A-11-97945 JP-A-10-224157

  The conventional frequency switching amplifier as described above has a problem that the bandwidth does not change because the number of stages of the matching circuit of the amplifier is not changed, and the wideband characteristic and the narrowband characteristic cannot be switched.

  Further, in the output matching circuit of other conventional frequency switching amplifiers, the variable capacitor and the variable inductor have a problem that the high-frequency signal is distorted because the capacitance value and the inductance are changed by the RF signal.

  The present invention has been made to solve the above-described problems, and its object is to change the frequency bandwidth, and even when a large RF signal is input, the element value is constant and does not distort. A frequency / bandwidth switching amplifier is obtained.

  The frequency / bandwidth switching amplifier according to the present invention includes an amplifier circuit, an input matching network connected to the input side of the amplifier circuit, and an output matching network connected to the output side of the amplifier circuit. A frequency / bandwidth switching amplifier, wherein at least one of the input matching network and the output matching network includes first and second high-pass filter networks connected in cascade, the first and second The high-pass filter network includes a capacitor connected in series to the signal line and an inductor connected in parallel to the signal line, and the first high-pass filter network is connected in parallel to the capacitor. And the second high-pass filter network further includes a second switch connected between the signal line and the inductor. Than is.

  The frequency / bandwidth switching amplifier according to the present invention can change the frequency bandwidth and has an effect that the element value is constant and is not distorted even when a large RF signal is input.

Embodiment 1 FIG.
A frequency / bandwidth switching amplifier according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a diagram showing a circuit configuration of a frequency / bandwidth switching amplifier according to Embodiment 1 of the present invention. In the following, in each figure, the same reference numerals indicate the same or corresponding parts.

  In FIG. 1, the frequency / bandwidth switching amplifier according to the first embodiment is provided with an input matching network 100, an FET (amplifier circuit) 200, and an output matching network 300.

  The output matching network 300 connected between the input terminal 1 and the output terminal 2 is provided with a first high-pass filter network 10 and a second high-pass filter network 20.

  The first high-pass filter network 10 is provided with a first series capacitor 11, a first switch 12, and a first parallel inductor 13.

  The second high-pass filter network 20 is provided with a second series capacitor 21, a second switch 22, and a second parallel inductor 23.

  The capacitance value of the first series capacitor 11 is C1, the inductance of the first parallel inductor 13 is L1, the capacitance value of the second series capacitor 21 is C2, and the inductance of the second parallel inductor 23 is L2. The real impedance when the FET 200 side is viewed from the input terminal 1 is ZL, and the real impedance when the output side is viewed from the output terminal 2 is Z0.

  The input matching network 100 is the same as the output matching network 300 although the circuit configuration is not shown.

  Next, the operation of the frequency / bandwidth switching amplifier according to the first embodiment will be described with reference to the drawings. FIG. 2 is a diagram showing wideband characteristics and narrowband characteristics of the input matching circuit network and the output matching network of the frequency / bandwidth switching amplifier according to the first embodiment of the present invention.

  The frequency / bandwidth switching amplifier according to the first embodiment has a wideband characteristic and a narrowband characteristic as shown in FIG. When the wideband characteristics of the frequency / bandwidth switching amplifier are used, the two second switches 22 of the input matching network 100 and the output matching network 300 are turned on, and the two first switches 12 are turned off. By setting the state, wideband characteristics can be obtained. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, the two second switches 22 of the input matching network 100 and the output matching network 300 are turned off and the two first switches 12 are turned on. Narrow band characteristics can be obtained by turning it on.

  In the frequency / bandwidth switching amplifier according to the first embodiment, it is confirmed that the wideband characteristic and the narrowband characteristic are switched. FIG. 2 shows that when ZL = 5Ω and Z0 = 50Ω, matching is possible over a wide band from a frequency band of 3.2 GHz to 4.0 GHz as a wideband characteristic, and matching is performed at 1.9 GHz as a narrowband characteristic. The output reflection of the output matching network 300 designed to be taken is shown.

  At this time, the values of the circuit elements 11, 13, 21, and 23 of the output matching network 300 of the frequency / bandwidth switching amplifier satisfy the expressions (1), (2), (3), and (4), and C1 = 1.53 pF, L1 = 1.41 nH, C2 = 5.69 pF, L2 = 0.38 nH. In addition, the matching frequency f2 having a narrow band characteristic and the matching frequency f1 having a wide band characteristic satisfy Expression (5).

  As shown in FIG. 2, the matching circuit of the frequency / bandwidth switching amplifier includes matching circuit elements 11, 13, and 21 when the second switch 22 is in an on state and the first switch 12 is in an off state. , 23 is −20 dB and allows a broadband RF signal from 3.13 GHz to 4.10 GHz to pass therethrough. Further, when the second switch 22 is changed from the on state to the off state and the first switch 12 is changed from the off state to the on state, only a narrowband signal of 1.87 GHz is passed.

  Thereby, the second switch 22 inserted in series with the parallel inductor 23 of the second high-pass filter network 20 and the first switch 12 inserted in parallel with the series capacitor 11 of the first high-pass filter network 10. By switching on / off, it can be confirmed that the wideband characteristics and the narrowband characteristics are effectively switched in the frequency / bandwidth switching amplifier. It is ideal that both the input matching network 100 and the output matching network 300 have the circuit configuration on the right side of FIG. 1, but only one has the circuit configuration on the right side of FIG. Even if it is, the same effect is produced.

Embodiment 2. FIG.
A frequency / bandwidth switching amplifier according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a diagram showing a circuit configuration of the input matching circuit network and the output matching circuit network of the frequency / bandwidth switching amplifier according to the second embodiment of the present invention.

  3, the matching circuit of the frequency / bandwidth switching amplifier according to the second embodiment includes a first low-pass filter network 30 and a second low-pass filter network between the input terminal 1 and the output terminal 2. 40 is provided.

  The first low-pass filter network 30 is provided with a first series inductor 31, a first switch 32, and a first parallel capacitor 33.

  The second low-pass filter circuit network 40 is provided with a second series inductor 41, a second switch 42, and a second parallel capacitor 43.

  The capacitance value of the first parallel capacitor 33 is C1, the inductance of the first series inductor 31 is L1, the capacitance value of the second parallel capacitor 43 is C2, and the inductance of the second series inductor 41 is L2. The real impedance when the input terminal 1 is viewed from the input side is ZL, and the real impedance when the output terminal 2 is viewed from the output side is Z0.

  Next, the operation of the frequency / bandwidth switching amplifier according to the second embodiment will be described with reference to the drawings. FIG. 4 is a diagram showing wideband characteristics and narrowband characteristics of the input matching circuit network and the output matching circuit network of the frequency / bandwidth switching amplifier according to the second embodiment of the present invention.

  When using the wideband characteristics of the frequency / bandwidth switching amplifier, the wideband characteristics can be obtained by turning on the second switch 42 and turning off the first switch 32. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, the narrow band characteristic can be obtained by turning off the second switch 42 and turning on the first switch 32.

  It is confirmed that the wideband characteristic and the narrowband characteristic are switched in the frequency / bandwidth switching amplifier according to the second embodiment. FIG. 4 shows that when ZL = 5Ω and Z0 = 50Ω, the narrow band characteristics can be matched at 4.0 GHz so that the wide band characteristics can be matched over a wide frequency band of 1.8 GHz to 3.0 GHz. Shows the output reflection of the designed matching circuit.

  At this time, the values of the circuit elements 33, 31, 43, and 41 of the matching circuit of the frequency / band variable amplifier satisfy the expressions (6), (7), (8), and (9), and C1 = 2.32 pF, L1 = 1.70 nH, C2 = 6.74 pF, and L2 = 0.60 nH. In addition, the matching frequency f2 having a narrow band characteristic and the matching frequency f1 having a wide band characteristic satisfy Expression (10).

  As shown in FIG. 4, the matching circuit of the frequency / bandwidth switching amplifier includes matching circuit elements 33, 31, 43 when the second switch 42 is in the on state and the first switch 32 is in the off state. , 41 is -10 dB and allows a broadband RF signal from 1.70 GHz to 3.18 GHz to pass through. Further, when the second switch 42 is changed from the on state to the off state and the first switch 32 is changed from the off state to the on state, only a signal of a narrow band of 4.0 GHz is passed.

  Thus, the second switch 42 inserted in series with the second parallel capacitor 43 of the second low-pass filter network 40 and the first series inductor 31 of the first low-pass filter network 30 are inserted in parallel. By switching ON / OFF of the first switch 32, it can be confirmed that the wideband characteristic and the narrowband characteristic are effectively switched in the frequency / bandwidth switching amplifier. It is ideal that both the input matching network and the output matching network have the circuit configuration of FIG. 3, but the same effect can be obtained even if only one of them has the circuit configuration of FIG. Play.

Embodiment 3 FIG.
A frequency / bandwidth switching amplifier according to Embodiment 3 of the present invention will be described with reference to FIGS. FIG. 5 is a diagram showing a circuit configuration of an input matching circuit network and an output matching circuit network of the frequency / bandwidth switching amplifier according to the third embodiment of the present invention.

  5, the matching circuit of the frequency / bandwidth switching amplifier according to the third embodiment includes a first high-pass filter network 10 and a second low-pass filter network between the input terminal 1 and the output terminal 2. 40 is provided.

  The first high-pass filter network 10 is provided with a first series capacitor 11 and a first parallel inductor 13.

  The second low-pass filter circuit network 40 is provided with a second series inductor 41, a second switch 42, and a second parallel capacitor 43.

  The capacitance value of the first series capacitor 11 is C1, the inductance of the first parallel inductor 13 is L1, the capacitance value of the second parallel capacitor 43 is C2, and the inductance of the second series inductor 41 is L2. The real impedance when the input terminal 1 is viewed from the input side is ZL, and the real impedance when the output terminal 2 is viewed from the output side is Z0.

  Next, the operation of the frequency / bandwidth switching amplifier according to the third embodiment will be described with reference to the drawings. FIG. 6 is a diagram showing wideband characteristics and narrowband characteristics of the input matching circuit network and the output matching circuit network of the frequency / bandwidth switching amplifier according to the third embodiment of the present invention.

  When the wideband characteristic of the frequency / bandwidth switching amplifier is used, the wideband characteristic can be obtained by turning on the second switch 42. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, the narrow band characteristic can be obtained by turning off the second switch 42.

  FIG. 6 shows the wideband characteristics when ZL = 15Ω and Z0 = 50Ω for the purpose of confirming that the wideband characteristics and the narrowband characteristics are switched in the frequency / bandwidth switching amplifier according to the third embodiment. The output reflection of a matching circuit designed to be matched at 1.8 GHz as a narrow band characteristic so that matching can be achieved over a wide frequency band of 2.0 GHz to 3.5 GHz.

At this time, the values of the circuit elements 11, 13, 43, and 41 of the matching circuit of the frequency / bandwidth switching amplifier satisfy the expressions (11), (12), (13), and (14), and C1 = 3.06 pF ,
L1 = 3.27 nH, C2 = 1.79 pF, and L2 = 0.55 nH. In addition, the matching frequency f2 having a narrow band characteristic and the matching frequency f1 having a wide band characteristic satisfy Expression (15).

  As shown in FIG. 6, in the matching circuit of the frequency / bandwidth switching amplifier, when the second switch 42 is in the ON state, the matching circuit elements 11, 13, 43, 41 are −15 dB from 1.8 GHz. A broadband RF signal up to 3.6 GHz is passed. Further, when the second switch 42 is switched from the on state to the off state, only a narrow band signal of 1.8 GHz is allowed to pass.

  Thus, by switching on / off the second switch 42 inserted in series with the parallel capacitor 43 of the second low-pass filter network 40, wideband characteristics and narrowband characteristics are effective in the frequency / bandwidth switching amplifier. It can be confirmed that it has been switched to. It is ideal that both the input matching network and the output matching network have the circuit configuration of FIG. 5, but the same effect can be obtained even if only one of them has the circuit configuration of FIG. Play.

Embodiment 4 FIG.
A frequency / bandwidth switching amplifier according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a diagram showing a circuit configuration of an input matching circuit network and an output matching circuit network of the frequency / bandwidth switching amplifier according to the fourth embodiment of the present invention.

  7, the matching circuit of the frequency / bandwidth switching amplifier according to the fourth embodiment includes a first high-pass filter network 10 and a second low-pass filter network between the input terminal 1 and the output terminal 2. 40 is provided.

  The first high-pass filter network 10 is provided with a first series capacitor 11, a first switch 12, and a first parallel inductor 13.

  The second low-pass filter network 40 is provided with a second series inductor 41 and a second parallel capacitor 43.

  The capacitance value of the first series capacitor 11 is C1, the inductance of the first parallel inductor 13 is L1, the capacitance value of the second parallel capacitor 43 is C2, and the inductance of the second series inductor 41 is L2. The real impedance when the input terminal 1 is viewed from the input side is ZL, and the real impedance when the output terminal 2 is viewed from the output side is Z0.

  Next, the operation of the frequency / bandwidth switching amplifier according to the fourth embodiment will be described with reference to the drawings. FIG. 8 is a diagram showing the wideband characteristics and the narrowband characteristics of the input matching circuit network and the output matching circuit network of the frequency / bandwidth switching amplifier according to the fourth embodiment of the present invention.

  When the wideband characteristic of the frequency / bandwidth switching amplifier is used, the wideband characteristic can be obtained by turning off the first switch 12. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, the narrow band characteristic can be obtained by turning on the first switch 12.

  FIG. 8 shows the wideband characteristics when ZL = 15Ω and Z0 = 50Ω for the purpose of confirming that the wideband characteristics and the narrowband characteristics are switched in the frequency / bandwidth switching amplifier according to the fourth embodiment. The output reflection of a matching circuit designed to be matched at 3.2 GHz as a narrowband characteristic so that matching can be achieved over a wide frequency band of 1.8 GHz to 3.0 GHz is shown.

  At this time, the values of the circuit elements 11, 13, 43, and 41 of the matching circuit of the frequency / bandwidth switching amplifier satisfy the expressions (16), (17), (18), and (19), and C1 = 2.63 pF L1 = 4.08 nH, C2 = 1.96 pF, and L2 = 1.07 nH. In addition, the matching frequency f2 having a narrow band characteristic and the matching frequency f1 having a wide band characteristic satisfy Expression (20).

  As shown in FIG. 8, in the matching circuit of the frequency / bandwidth switching amplifier, when the first switch 12 is in the OFF state, the matching circuit elements 11, 13, 43, and 41 are −15 dB from 1.72 GHz. 3. A broadband RF signal up to 1 GHz is passed. Further, when the first switch 12 is switched from the off state to the on state, only a narrow-band signal of 3.2 GHz is passed.

  Thus, by switching on / off of the first switch 12 inserted in parallel with the series capacitor 11 of the first high-pass filter network 10, wideband characteristics and narrowband characteristics are effective in the frequency / bandwidth switching amplifier. It can be confirmed that it has been switched to. It is ideal that both the input matching network and the output matching network have the circuit configuration of FIG. 7, but the same effect can be obtained even if only one of them has the circuit configuration of FIG. Play.

Embodiment 5 FIG.
A frequency / bandwidth switching amplifier according to a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a diagram showing the circuit configuration of the input matching circuit network and the output matching circuit network of the frequency / bandwidth switching amplifier according to the fifth embodiment of the present invention.

  In FIG. 9, the matching circuit of the frequency / bandwidth switching amplifier according to the fifth embodiment includes a first low-pass filter network 30 and a second high-pass filter network between the input terminal 1 and the output terminal 2. 20 is provided.

  The first low-pass filter network 30 is provided with a first series inductor 31 and a first parallel capacitor 33.

  The second high-pass filter network 20 is provided with a second series capacitor 21, a second switch 22, and a second parallel inductor 23.

  The capacitance value of the first parallel capacitor 33 is C1, the inductance of the first series inductor 31 is L1, the capacitance value of the second series capacitor 21 is C2, and the inductance of the second parallel inductor 23 is L2. The real impedance when the input terminal 1 is viewed from the input side is ZL, and the real impedance when the output terminal 2 is viewed from the output side is Z0.

  Next, the operation of the frequency / bandwidth switching amplifier according to the fifth embodiment will be described with reference to the drawings. FIG. 10 is a diagram showing the wideband characteristics and narrowband characteristics of the input matching network and the output matching network of the frequency / bandwidth switching amplifier according to the fifth embodiment of the present invention.

  When the wideband characteristic of the frequency / bandwidth switching amplifier is used, the wideband characteristic can be obtained by turning on the second switch 22. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, the narrow band characteristic can be obtained by turning off the second switch 22.

  FIG. 10 shows the wideband characteristics when ZL = 20Ω and Z0 = 50Ω for the purpose of confirming that the wideband characteristics and the narrowband characteristics are switched in the frequency / bandwidth switching amplifier according to the fifth embodiment. The output reflection of a matching circuit designed to be matched at 2.4 GHz as a narrow band characteristic so that matching can be achieved over a wide frequency band of 1.0 GHz to 2.2 GHz is shown.

  At this time, the values of the circuit elements 33, 31, 21, and 23 of the matching circuit of the frequency / bandwidth switching amplifier satisfy the expressions (21), (22), (23), and (24), and C1 = 1.63 pF. L1 = 2.20 nH, C2 = 8.04 pF, and L2 = 4.80 nH. In addition, the matching frequency f2 having the narrow band characteristic and the matching frequency f1 having the wide band characteristic satisfy Expression (25).

  As shown in FIG. 10, in the matching circuit of the frequency / bandwidth switching amplifier, when the second switch 22 is in the ON state, the matching circuit elements 33, 31, 21, and 23 are −20 dB from 1.0 GHz. A broadband RF signal up to 2.2 GHz is passed. Further, when the second switch 22 is switched from the on state to the off state, only a 2.4 GHz narrow-band signal is allowed to pass.

  Thereby, by switching on / off of the second switch 22 inserted in series with the parallel inductor 23 of the second high-pass filter network 20, wideband characteristics and narrowband characteristics are effective in the frequency / bandwidth switching amplifier. It can be confirmed that it has been switched to. It is ideal that both the input matching network and the output matching network have the circuit configuration of FIG. 9, but the same effect can be obtained even if only one of them has the circuit configuration of FIG. Play.

Embodiment 6 FIG.
A frequency / bandwidth switching amplifier according to a sixth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a diagram showing circuit configurations of an input matching circuit network and an output matching circuit network of the frequency / bandwidth switching amplifier according to the sixth embodiment of the present invention.

  In FIG. 11, the matching circuit of the frequency / bandwidth switching amplifier according to the sixth embodiment includes a first low-pass filter network 30 and a second high-pass filter network between the input terminal 1 and the output terminal 2. 20 is provided.

  The first low-pass filter network 30 is provided with a first series inductor 31, a first switch 32, and a first parallel capacitor 33.

  The second high-pass filter network 20 is provided with a second series capacitor 21 and a second parallel inductor 23.

  The capacitance value of the first parallel capacitor 33 is C1, the inductance of the first series inductor 31 is L1, the capacitance value of the second series capacitor 21 is C2, and the inductance of the second parallel inductor 23 is L2. The real impedance when the input terminal 1 is viewed from the input side is ZL, and the real impedance when the output terminal 2 is viewed from the output side is Z0.

  Next, the operation of the frequency / bandwidth switching amplifier according to the sixth embodiment will be described with reference to the drawings. FIG. 12 is a diagram showing the wideband characteristics and narrowband characteristics of the input matching network and the output matching network of the frequency / bandwidth switching amplifier according to the sixth embodiment of the present invention.

  When the wideband characteristic of the frequency / bandwidth switching amplifier is used, the wideband characteristic can be obtained by turning off the first switch 32. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, the narrow band characteristic can be obtained by turning on the first switch 32.

  FIG. 12 shows wideband characteristics when ZL = 15Ω and Z0 = 50Ω for the purpose of confirming that the wideband characteristics and the narrowband characteristics are switched in the frequency / bandwidth switching amplifier according to the sixth embodiment. The output reflection of a matching circuit designed to be matched at 1.37 GHz as a narrowband characteristic so that matching can be achieved over a wide frequency band from 1.5 GHz to 2.4 GHz.

  At this time, the values of the circuit elements 33, 31, 21, and 23 of the matching circuit of the frequency / bandwidth switching amplifier satisfy the expressions (26), (27), (28), and (29), and C1 = 1.33 pF. L1 = 2.41 nH, C2 = 5.30 pF, and L2 = 2.93 nH. In addition, the matching frequency f2 having a narrow band characteristic and the matching frequency f1 having a wide band characteristic satisfy Expression (30).

  As shown in FIG. 12, in the matching circuit of the frequency / bandwidth switching amplifier, when the first switch 32 is in the OFF state, the matching circuit elements 33, 31, 21, and 23 are −15 dB from 1.5 GHz. A broadband RF signal up to 2.4 GHz is passed. Further, when the first switch 32 is switched from the off state to the on state, only a 1.37 GHz narrow-band signal is allowed to pass.

  Thus, by switching on / off the first switch 32 inserted in parallel with the series inductor 31 of the first low-pass filter network 30, wideband characteristics and narrowband characteristics are effective in the frequency / bandwidth switching amplifier. It can be confirmed that it has been switched to. It is ideal that both the input matching network and the output matching network have the circuit configuration of FIG. 11, but the same effect can be obtained even if only one of them has the circuit configuration of FIG. Play.

Embodiment 7 FIG.
A frequency / bandwidth switching amplifier according to Embodiment 7 of the present invention will be described with reference to FIG. FIG. 13 is a diagram showing a circuit configuration of the input matching circuit network and the output matching circuit network of the frequency / bandwidth switching amplifier according to the seventh embodiment of the present invention.

  In FIG. 13, the matching circuit of the frequency / bandwidth switching amplifier according to the seventh embodiment includes a first high-pass filter network 10 and a second high-pass filter network between the input terminal 1 and the output terminal 2. 20 and a power source 3 connected in series with a resistor 4 connected in parallel to the signal line.

  The first high-pass filter network 10 is provided with a first series capacitor 11, a first pin diode 14, and a first parallel inductor 13.

  The second high-pass filter network 20 is provided with a second series capacitor 21, a second pin diode 24, and a second parallel inductor 23.

  In the seventh embodiment, a pin diode is applied to the switch of the matching circuit of the frequency / band switching amplifier of the first embodiment. The second pin diode 24 is connected in series with the second parallel inductor 23 so that the direction from the ground to the signal line is the forward direction. The first pin diode 14 is connected in parallel with the first series capacitor 11 so that the direction from the input terminal 1 of the matching circuit to the output terminal 2 of the matching circuit is the forward direction.

  Next, the operation of the frequency / bandwidth switching amplifier according to the seventh embodiment will be described with reference to the drawings.

  When using the wideband characteristics of the frequency / bandwidth switching amplifier, a negative voltage is applied from the power source 3 to the matching circuit, whereby the second pin diode 24 is turned on and the first pin diode 14 is turned off. Therefore, broadband characteristics can be obtained. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, the second pin diode 24 is turned off by applying a positive voltage from the power source 3 to the matching circuit, and the first pin diode 14 is turned off. Since the is turned on, narrow band characteristics can be obtained.

  Thus, the second pin diode 24 inserted in series with the second parallel inductor 23 of the second high-pass filter network 20 and the first series capacitor 11 of the first high-pass filter network 10 are inserted in parallel. By switching on / off of the first pin diode 14, the wideband characteristic and the narrowband characteristic of the frequency / bandwidth switching amplifier are effectively switched. It is ideal that both the input matching network and the output matching network have the circuit configuration of FIG. 13, but the same effect can be obtained when only one of them has the circuit configuration of FIG. Play. Needless to say, the seventh embodiment can be applied to the second to sixth embodiments. Furthermore, not only a pin diode but also a mechanical switch such as a pin diode or a MEMS switch, or a semiconductor switch such as a transistor (FET) switch may be used as a switch. An example using an FET switch is the following embodiment 8. explain.

Embodiment 8 FIG.
A frequency / bandwidth switching amplifier according to Embodiment 8 of the present invention will be described with reference to FIG. FIG. 14 is a diagram showing circuit configurations of an input matching circuit network and an output matching circuit network of the frequency / bandwidth switching amplifier according to the eighth embodiment of the present invention.

  In FIG. 14, the matching circuit of the frequency / bandwidth switching amplifier according to the eighth embodiment includes a first high-pass filter network 10 and a second high-pass filter network between the input terminal 1 and the output terminal 2. 20 and an inverter network 50 connected to the first power supply 3 are provided.

  The first high-pass filter network 10 is provided with a first series capacitor 11, a first FET 15, and a first parallel inductor 13.

  The second high-pass filter network 20 is provided with a second series capacitor 21, a second FET 25, and a second parallel inductor 23.

  The inverter network 50 is provided with a pMOS transistor 51, an nMOS transistor 52, and a second power source 5.

  In the eighth embodiment, an FET is applied to the switch of the matching circuit of the frequency / band switching amplifier of the first embodiment. The second power supply 5 always applies the operating voltages of the pMOS transistor 51 and the nMOS transistor 52.

  Next, the operation of the frequency / bandwidth switching amplifier according to the seventh embodiment will be described with reference to the drawings.

  When using the wideband characteristics of the frequency / bandwidth switching amplifier, by applying a negative voltage to the pMOS transistor 51 and the nMOS transistor 52 from the first power supply 3, the pMOS transistor 51 is turned on, and the nMOS transistor 52 Since the second FET 25 is turned on and the first FET 15 is turned off at the same time, a wide band characteristic can be obtained. When the narrow band characteristic of the frequency / bandwidth switching amplifier is used, a positive voltage is applied to the pMOS transistor 51 and the nMOS transistor 52 from the first power supply 3, whereby the pMOS transistor 51 is turned off, and the nMOS Since the transistor 52 is turned on, the second FET 25 is turned off at the same time, and the first FET 15 is turned on, a narrow band characteristic can be obtained.

  As a result, the second FET 25 inserted in series with the second parallel inductor 23 of the second high-pass filter network 20 and the first series capacitor 11 of the first high-pass filter network 10 inserted in parallel. By switching on / off of one FET 15, the wideband characteristics and narrowband characteristics of the frequency / bandwidth switching amplifier are effectively switched. It is ideal that both the input matching network and the output matching network have the circuit configuration of FIG. 14, but the same effect can be obtained even if only one of them has the circuit configuration of FIG. Play. In each embodiment, a line or a wire can be used as an inductor, and a stub or a coupled line can be used as a capacitor.

It is a figure which shows the circuit structure of the frequency and bandwidth switching amplifier which concerns on Embodiment 1 of this invention. It is a figure which shows the wideband characteristic and narrowband characteristic of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 1 of this invention, and an output matching network. It is a figure which shows the circuit structure of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 2 of this invention, and an output matching network. It is a figure which shows the wideband characteristic and narrowband characteristic of the input matching circuit network and output matching circuit network of the frequency / bandwidth switching amplifier which concern on Embodiment 2 of this invention. It is a figure which shows the circuit structure of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 3 of this invention, and an output matching network. It is a figure which shows the wideband characteristic and narrowband characteristic of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 3 of this invention, and an output matching network. It is a figure which shows the circuit structure of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 4 of this invention, and an output matching network. It is a figure which shows the wideband characteristic and narrowband characteristic of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 4 of this invention, and an output matching network. It is a figure which shows the circuit structure of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 5 of this invention, and an output matching network. It is a figure which shows the wideband characteristic and narrowband characteristic of the input matching circuit network and output matching circuit network of the frequency / bandwidth switching amplifier which concern on Embodiment 5 of this invention. It is a figure which shows the circuit structure of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 6 of this invention, and an output matching network. It is a figure which shows the wideband characteristic and narrowband characteristic of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 6 of this invention, and an output matching network. It is a figure which shows the circuit structure of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 7 of this invention, and an output matching network. It is a figure which shows the circuit structure of the input matching network of the frequency / bandwidth switching amplifier which concerns on Embodiment 8 of this invention, and an output matching network. It is a figure which shows the structure of the conventional frequency switching amplifier. It is a figure which shows the structure of the other conventional frequency switching amplifier.

Explanation of symbols

  1 input terminal, 2 output terminal, 3 power supply, 1st power supply, 4 resistor, 5 2nd power supply, 10 1st high-pass filter network, 11 1st series capacitance, 12 1st switch, 13 1st switch Parallel inductor, 14 first pin diode, 20 second high-pass filter network, 21 second series capacitance, 22 second switch, 23 second parallel inductor, 24 second pin diode, 30 first Low pass filter network, 31 first series inductor, 32 first switch, 33 first parallel capacitance, 40 second low pass filter network, 41 second series inductor, 42 second switch, 43 second 2 parallel capacitors, 50 inverter network, 51 pMOS transistor, 52 nMOS transistor, 100 input matching network, 200 FET, 00 output matching network.

Claims (9)

A frequency / bandwidth switching amplifier comprising an amplifier circuit, an input matching network connected to the input side of the amplifier circuit, and an output matching network connected to the output side of the amplifier circuit,
At least one of the input matching network and the output matching network has first and second high-pass filter networks connected in cascade,
The first and second high pass filter networks are:
A capacitor connected in series with the signal line;
Each including an inductor connected in parallel to the signal line,
The first high pass filter network is:
A first switch connected in parallel to the capacitor;
The second high pass filter network is:
A frequency / bandwidth switching amplifier, further comprising a second switch connected between the signal line and the inductor. A frequency / bandwidth switching amplifier comprising an amplifier circuit, an input matching network connected to the input side of the amplifier circuit, and an output matching network connected to the output side of the amplifier circuit,
At least one of the input matching network and the output matching network has first and second low-pass filter networks connected in cascade,
The first and second low pass filter networks are:
An inductor connected in series to the signal line;
Each including a capacitor connected in parallel to the signal line,
The first low pass filter network is:
A first switch connected in parallel to the inductor;
The second low pass filter network is:
A frequency / bandwidth switching amplifier, further comprising a second switch connected between the signal line and the capacitor. A frequency / bandwidth switching amplifier comprising an amplifier circuit, an input matching network connected to the input side of the amplifier circuit, and an output matching network connected to the output side of the amplifier circuit,
At least one of the input matching network and the output matching network has a cascaded high-pass filter network and low-pass filter network,
The high pass filter network is:
A first capacitor connected in series to the signal line;
A first inductor connected in parallel to the signal line,
The low pass filter network is:
A second inductor connected in series to the signal line;
A second capacitor connected in parallel to the signal line;
A frequency / bandwidth switching amplifier comprising: a switch connected between the signal line and the second capacitor. A frequency / bandwidth switching amplifier comprising an amplifier circuit, an input matching network connected to the input side of the amplifier circuit, and an output matching network connected to the output side of the amplifier circuit,
At least one of the input matching network and the output matching network has a cascaded high-pass filter network and low-pass filter network,
The high pass filter network is:
A first capacitor connected in series to the signal line;
A first inductor connected in parallel to the signal line;
A switch connected in parallel to the first capacitor,
The low pass filter network is:
A second inductor connected in series to the signal line;
And a second capacitor connected in parallel to the signal line. A frequency / bandwidth switching amplifier. A frequency / bandwidth switching amplifier comprising an amplifier circuit, an input matching network connected to the input side of the amplifier circuit, and an output matching network connected to the output side of the amplifier circuit,
At least one of the input matching network and the output matching network has a cascaded low-pass filter network and high-pass filter network,
The low pass filter network is:
A first inductor connected in series to the signal line;
And a first capacitor connected in parallel to the signal line,
The high pass filter network is:
A second capacitor connected in series to the signal line;
A second inductor connected in parallel to the signal line;
A frequency / bandwidth switching amplifier, comprising: a switch connected between the signal line and the second inductor. A frequency / bandwidth switching amplifier comprising an amplifier circuit, an input matching network connected to the input side of the amplifier circuit, and an output matching network connected to the output side of the amplifier circuit,
At least one of the input matching network and the output matching network has a cascaded low-pass filter network and high-pass filter network,
The low pass filter network is:
A first inductor connected in series to the signal line;
A first capacitor connected in parallel to the signal line;
A switch connected in parallel to the first inductor,
The high pass filter network is:
A second capacitor connected in series to the signal line;
A frequency / bandwidth switching amplifier, comprising: a second inductor connected in parallel to the signal line. The frequency / band according to any one of claims 1 to 6, wherein the first switch, the second switch, or the switch is one of a mechanical switch and a semiconductor switch. Width switching amplifier. The frequency / bandwidth switching according to any one of claims 1 to 7, wherein the inductor, the first inductor, or the second inductor is one of a line and a wire. amplifier. The frequency / bandwidth according to any one of claims 1 to 8, wherein the capacitor, the first capacitor, or the second capacitor is one of a stub and a coupled line. Switching amplifier.

Images