JPH10145270A - High-frequency device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the device small and light in weight by incorporating SAW filters with a multilayer base plate, which is overlapped by plural dielectric layers that constitute a high-frequency switch which has a specific number of ports. SOLUTION: A high-frequency device 10 consists of a high-frequency switch SW10 to which two antennas ANT1 and ANT2 are connected, an LC filter F11 which is a low-pass filter and SAW filters F12 and F13 which are band-pass filters. That is, the device 10 consists of a multilayer base plate which is overlapped by plural dielectric layers, the switch SW10 which consists of a diode that is mounted on the multilayer base plate, a transmission line that is contained in the multilayer base plate and a condenser and has at least four ports, and the filters F12 and F13 which are mounted on the multilayer base plate. In this way, the switch SW10 and the filters F12 and F13 are formed on the multilayer base plate that are overlapped by plural dielectric layers and they are formed integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency device used for a mobile communication device, for example, an automobile telephone, a portable telephone and the like.

[0002]

2. Description of the Related Art FIG. 14 is a block diagram of a general high-frequency device. This high-frequency device 1 is a composite high-frequency component for protecting the receiver from the transmission output at the time of transmission and supplying the reception signal to the receiver at the time of reception in order to share the two antennas ANT1 and ANT2 for the transmission Tx and the reception Rx. Yes, miniaturized, surface mountable filter F
By mounting electronic components such as 1, F2, switch SW and the like on a high-density printed wiring board, miniaturization and weight reduction have been realized.

[0003] It is expected that mobile communication devices typified by mobile phones and mobile phones equipped with the high-frequency device 1 will continue to be further reduced in size and weight while improving their functions. It is indispensable to further reduce the size and weight of the mounted high-frequency device 1.

[0004]

However, in a conventional high-frequency device, since discrete filters and switches are mounted on a printed wiring board,
There is a problem that further miniaturization and weight reduction are difficult. In particular, in the case of a filter, in general, the performance and the shape and size of the filter are inversely proportional, and the shape and size are increased as the performance of the filter is increased, and the size and weight of the filter are reduced. It hinders. Conversely, downsizing the filter due to size restrictions of a mobile communication device equipped with a high-frequency device imposes a compromise on device performance due to insufficient filter characteristics.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to provide a high-frequency device which can be reduced in size and weight by integrating a high-frequency switch and a filter. With the goal.

[0006]

In order to achieve the above object, a high-frequency device according to the present invention comprises a multilayer substrate formed by laminating a plurality of dielectric layers; a diode mounted on the multilayer substrate; It is characterized by comprising a high-frequency switch having at least four ports including a built-in transmission line and a capacitor, and a SAW filter mounted on the multilayer substrate.

[0007] Further, the present invention is characterized in that an LC filter comprising a transmission line and a capacitor is built in the multilayer substrate.

Further, a low-temperature fired ceramic substrate is used as the multilayer substrate.

According to the high-frequency device of the present invention, the high-frequency switch and the filter are formed on a multi-layer substrate formed by laminating a plurality of dielectric layers, and are integrated to provide a conventional discrete filter and high-frequency switch. The overall dimensions are smaller than those mounted and connected on a substrate. Further, by designing the filter and the high-frequency switch at the same time, it is possible to design the filter and the high-frequency switch with impedance matching.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the high-frequency device according to the present invention. High frequency device 1
0 is a high-frequency switch SW10 to which the two antennas ANT1 and ANT2 are connected, and L is a low-pass filter.
It comprises a C filter F11 and SAW filters F12 and F13 which are band-pass filters.

FIG. 2 is a schematic circuit diagram of a high-frequency switch constituting the high-frequency device of FIG. The high-frequency switch SW10 is used for an antenna switching circuit of a mobile communication device typified by a mobile phone and a mobile phone typified by a diversity system after detection, and includes first to fifth ports P1 to P5.
Is a five-port high-frequency switch. Although not shown, SAW is connected to the first and fifth ports P1 and P5.
Receiver circuit Rx via filters F12 and F13 (FIG. 1)
1, Rx2 (FIG. 1), antennas ANT1, ANT2 (FIG. 1) at the second and fourth ports P2, P4, and transmission circuit Tx at the third port P3 via an LC filter F11 (FIG. 1). Connected respectively.

FIG. 3 shows a specific circuit diagram of the high-frequency switch of FIG. The first port P1 is connected to a capacitor 11a,
It is connected to the second port P2 via the transmission line 12a and the capacitor 11b. Capacitor 11a and transmission line 12
a is connected to the cathode of the diode 13a, and the anode of the diode 13a is connected to the capacitor 11a.
c and grounded, and connected to a control voltage terminal 16a via a resistor 15a. Also, the transmission line 12a
The connection point between the transmission line 12b and the capacitor 11d is grounded via the transmission line 12b and the capacitor 11d, and the connection point between the transmission line 12b and the capacitor 11d is connected to the control voltage terminal 16b.

The second port P2 is connected to the anode of the diode 13b via the capacitor 11e, and the connection point between the capacitor 11e and the diode 13b is connected to the transmission line 1
2c and the capacitor 11f are grounded. The cathode of the diode 13b is connected to the third port P3 via the capacitor 11g,
3c, and is grounded via a transmission line 12d and a capacitor 11h. Also, transmission line 1
The connection point between 2d and the capacitor 11h is the control voltage terminal 1
6c.

Further, the cathode of the diode 13c is
Connected to the fourth port P4 via the capacitor 11i,
The connection point between the diode 13c and the capacitor 11i is grounded via the transmission line 12e and the capacitor 11j.
A connection point between the transmission line 12e and the capacitor 11j and a connection point between the transmission line 12c and the capacitor 11f are connected via a resistor 15b and a resistor 15c.
The connection point between the resistor and the resistor 15c is connected to the control voltage terminal 16d.

The fourth port P4 is connected to a fifth port P5 via a capacitor 11k, a transmission line 12f and a capacitor 111. The connection point between the capacitor 11k and the transmission line 12f is connected to the transmission line 12g and the capacitor 11k.
m, the transmission line 12g and the capacitor 11
The connection point with m is connected to the control voltage terminal 16e. Further, a connection point between the transmission line 12f and the capacitor 11l is connected to a cathode of a diode 13d, and an anode of the diode 13d is grounded via a capacitor 11n and connected to a control voltage terminal 16 via a resistor 15d.
f.

FIG. 4 is a circuit diagram of an LC filter constituting the high-frequency device of FIG. LC filter F11 is
This is a Butterworth type low-pass filter, and transmission lines 12h and 12i are provided between one port Pa and the other port Pb.
Is connected. Also, the transmission line 12h and one port Pa
, The connection point between the transmission line 12h and the transmission line 12i, and the connection point between the transmission line 12i and the other port Pb are grounded via capacitors 11o, 11p and 11q, respectively. Then, one port Pa of the LC filter F11
And the third port P3 (FIG. 3) of the high-frequency switch SW10.

FIGS. 5 (a) to 5 (h), 6 (a) to 6 (f), and 7 (a) to 7 (d) show respective components constituting the high-frequency device 10 of FIG. FIG. 3 shows a top view and a bottom view of a dielectric layer. This high-frequency composite component 10 is a multi-layer board (not shown) including a transmission line and a capacitor constituting the high-frequency switch SW10 in FIG. 3 and the LC filter F11 in FIG.
including. This multilayer substrate is, for example, 850 ° C. to 1000
It is formed by sequentially laminating first to nineteenth dielectric layers a to s made of a low-temperature fired ceramic mainly composed of barium oxide, aluminum oxide and silica, which can be fired at a temperature of ° C.

On the upper surfaces of the second to eighth, tenth, twelfth, sixteenth, and eighteenth dielectric layers b to h, j, l, p, and r, capacitor electrodes C11 to C14, C15 and C16, C17 ~
C20, C21 and C22, C23 to C26, C27 and C
28, C29-C32, C33-C39, C40-C4
2, C43 to C45 and C46 to C48 are respectively formed. Further, the fourth, twelfth, and fourteenth dielectric layers d,
On the upper surfaces of k and n, strip line electrodes SL11, S
L12, SL13, and SL14 to SL19 are respectively formed.

Further, ground electrodes G11 to G15 are formed on the upper surfaces of the ninth, thirteenth, fifteenth, seventeenth, and nineteenth dielectric layers i, m, o, q, and s, respectively. On the lower surface of the nineteenth dielectric layer s (designated by reference numeral su in FIG. 7D), a high-frequency switch S is provided as an external terminal.
First, second, fourth and fifth ports P1, P2 of W10,
Rx1, ANT1, ANT2, Rx2, V1 to V6 connected to P4, P5 and control terminals 16a to 16f, respectively.
And Tx connected to the other port Pb of the LC filter F11 and G connected to the ground electrodes G11 to G15 are formed. The third port P3 of the high-frequency switch SW10 and the other port Pa of the LC filter F11 are connected by a via-hole electrode (not shown) or the like inside the multilayer substrate.

Then, signal line electrodes (not shown) and via-hole electrodes (not shown) are formed in necessary places on the first to nineteenth dielectric layers a to s, and the via holes are formed through the via-hole electrodes. Capacitor electrodes C11 to C48, strip line electrodes SL11 to SL19, ground electrodes G11 to G1
5. External terminals ANT1, ANT2, Rx1, Rx2, V
1 to V6, Tx, and G are appropriately connected.

The capacitors 11a to 11n of the high-frequency switch SW10 are respectively connected to a capacitor electrode C33,
C37, C43 and C46, C45 and C48, C39, C
36, C34, C11, C15, C17, C21 and C2
3, C27 and C29, C12, C15, C18 and C21
C24, C27 and C30, C13, C16, C19, C22, C25, C28 and C31, C14, C16 and C
20, C22, C26, C28, C32, C35, C4
4 and C47 and C38. The capacitors 11o to 11q of the LC filter F11 are configured by capacitor electrodes C40, C41, and C42, respectively.

Further, the transmission lines 12a to 12g of the high frequency switch SW10 are connected to the strip line electrode SL1.
1, SL14, SL15, SL16, SL17, SL1
8, SL19. Also, the LC filter F11
The transmission lines 12h and 12i of the
L12 and SL13.

With the above configuration, the transmission lines 12a to 12g and the capacitors 11a to 11n constituting the high-frequency switch SW10 in FIG. 3 and the LC filter F1 in FIG.
1 and the transmission lines 12h and 12i and the capacitor 1
A multilayer substrate containing 1o to 11q is formed. Then, diodes 13a to 13d and resistors 15a to 15d constituting the high-frequency switch SW10 of FIG.
By mounting the SAW filters F12 and F13, the high-frequency device 10 is formed. Note that the resistor 15a
15d can also be formed as printed resistors on the surface or inside of the multilayer substrate.

FIG. 8 is a block diagram showing a high-frequency device according to a second embodiment of the present invention. High frequency device 20
Is a high-frequency switch SW shown in FIGS. 10, 12, and 13.
20, SW30, and SW31, an LC filter F21 that is a low-pass filter, and a SAW filter F22 that is a band-pass filter. Note that LC
As the filter F21, a Butterworth type low-pass filter as shown in FIG. 4 is used.

FIG. 9 is a schematic circuit diagram of a high-frequency switch constituting the high-frequency device of FIG. The high-frequency switch SW20 is used for an antenna switching circuit of a mobile communication device represented by a mobile phone or a mobile phone using an antenna diversity system, and includes first to fourth ports P1 to P4.
4 is a four-port high-frequency switch. Although not shown, the first and second ports P1 and P2 are provided with antennas ANT1 and ANT2 (FIG. 8), and the third port P3 is provided with a transmission circuit Tx via an LC filter F21 (FIG. 8).
(FIG. 8), but the fourth port P4 has a SAW filter F22.
The receiving circuits Rx (FIG. 8) are connected to each other via (FIG. 8).

FIG. 10 shows a specific circuit diagram of the high frequency switch of FIG. The high-frequency switch SW20 includes a diode 21a between the first and third ports P1 and P3, a diode 21b between the first and fourth ports P1 and P4, a diode 21c between the second and third ports P2 and P3, The diode 21d is connected between the second and fourth ports P2 and P4.

The first port P1 is connected to the anode of the diode 21a and the cathode of the diode 21b. The connection point between the first port P1 and the diodes 21a and 21b is grounded via the transmission line 22a and the capacitor 23a. One end of a resistor 24a is connected to a connection point between the transmission line 22a and the capacitor 23a, and the other end of the resistor 24a is connected to a control voltage terminal 25a.

The second port P2 is connected to the cathode of the diode 21c and the anode of the diode 21d.
The connection point between the port P2 and the diodes 21c and 21d is
Grounded via the transmission line 22b and the capacitor 23b. One end of a resistor 24b is connected to a connection point between the transmission line 22b and the capacitor 23b, and the other end of the resistor 24b is connected to a control voltage terminal 25a. That is, the control voltage terminal 25a is connected between the resistors 24a and 24b.

The third port P3 is connected to the cathode of the diode 21a and the anode of the diode 21c. The connection point between the third port P3 and the diodes 21a and 21c is grounded via the transmission line 22c and the capacitor 23c. One end of a resistor 24c is connected to a connection point between the transmission line 22c and the capacitor 23c, and the other end of the resistor 24c is connected to a control voltage terminal 25b.

The fourth port P4 is connected to the anode of the diode 21b and the cathode of the diode 21d.
The connection point between the port P4 and the diodes 21b and 21d is
Grounded via the transmission line 22d and the capacitor 23d. One end of a resistor 24d is connected to a connection point between the transmission line 22d and the capacitor 23d, and the other end of the resistor 24d is connected to a control voltage terminal 25b. That is, the control voltage terminal 25b is connected between the resistors 24c and 24d.

FIG. 11 shows another schematic circuit diagram of the high-frequency switch constituting the high-frequency device of FIG. The high frequency switches SW30 and SW31 are PDC (Personal Digita
l Cellular) This is a four-port high-frequency switch having first to fourth ports P1 to P4, which is used for an antenna switching circuit of a mobile communication device typified by a mobile phone or a mobile phone using a diversity system compatible with the diversity system. Although not shown, the transmission circuit Tx is connected to the first port P1 via an LC filter F21 (FIG. 8) which is a low-pass filter.
(FIG. 8), receiving circuits via antennas ANT1 and ANT2 (FIG. 8) at the second and fourth ports P2 and P4, and a SAW filter F22 (FIG. 8) as a band-pass filter at the third port P3. Rx (FIG. 8) are respectively connected.

FIG. 12 shows a specific circuit diagram of the high frequency switch of FIG. In the high frequency switch SW30,
The first port P1 is connected to the anode of the diode 32a via the capacitor 31a, and the cathode of the diode 32a is connected to the second port P2 via the capacitor 31b. Also, a capacitor 31a and a diode 32
The connection point with a is grounded via the transmission line 33a and the capacitor 31c. Further, a connection point between the transmission line 33a and the capacitor 31c is connected to the control voltage terminal 34a.

The second port P2 is also connected to one end of the transmission line 33b via the capacitor 31b. The other end of the transmission line 33b is connected to one end of the transmission line 33c, and the other end of the transmission line 33c is connected to the third port P3 via the capacitor 31d. Also, the transmission line 33b
The connection point between the transmission line 33c and the transmission line 33c is connected to the anode of the diode 32b, and the cathode of the diode 32b is grounded via the capacitor 31e. Further, a connection point between the diode 32b and the capacitor 31e is connected to a resistor 35a.
Grounded.

The third port P3 is also connected to the cathode of the diode 32c via the capacitor 31d. The anode of the diode 32c is connected to the capacitor 31f.
To the fourth port P4. The connection point between the diode 32c and the capacitor 31f is connected to the transmission line 3
3d and ground via the capacitor 31g. further,
A connection point between the transmission line 33d and the capacitor 31g is connected to the control voltage terminal 34b.

FIG. 13 shows another specific circuit diagram of the high-frequency switch of FIG. In the high-frequency switch SW31, the first port P1 is connected to the anode of the diode 42a via the capacitor 41a.
Is connected to the second port P via a capacitor 41b.
2 is connected. The connection point between the capacitor 41a and the diode 42a is connected to the transmission line 43a and the capacitor 41a.
c is grounded. Further, a connection point between the transmission line 43a and the capacitor 41c is connected to the control voltage terminal 44a.

The second port P2 is also connected to one end of the transmission line 43b via a capacitor 41b. The other end of the transmission line 43b is connected to the anode of the diode 42b via the capacitor 41d.
Is connected to the third port P via a capacitor 41e.
3 is connected. The transmission line 43b and the capacitor 4
1d is connected to the anode of the diode 42c, and the cathode of the diode 42c is connected to the capacitor 41c.
Grounded via f.

Further, the diode 42c and the capacitor 4
The connection point with 1f is grounded via a resistor 45a. The connection point between the capacitor 41d and the diode 42b is grounded via the transmission line 43c and the capacitor 41g. Further, a connection point between the transmission line 43c and the capacitor 41g is connected to the control voltage terminal 44b.

The third port P3 is also connected to one end of a transmission line 43d via a capacitor 41e. The other end of the transmission line 43d is connected to the fourth terminal via a capacitor 41h.
Connected to port P4. The connection point between the transmission line 43d and the capacitor 41h is connected to the anode of the diode 42d, and the cathode of the diode 42d is grounded via the capacitor 41i. In addition, diode 4
The connection point between 2d and capacitor 41i is grounded via resistor 45b.

In the second embodiment having the circuits shown in FIGS. 10, 12 and 13, as in the first embodiment, a capacitor electrode forming a capacitor and a strip line electrode forming a transmission line are provided. May be formed in a multilayer substrate.

As described above, according to the high-frequency devices of the first and second embodiments, the SAW is formed on the multilayer substrate formed by laminating a plurality of dielectric layers constituting the high-frequency switch having four ports and five ports. A high-frequency switch and a SAW in a printed wiring board are compared with a conventional discrete high-frequency switch and filter mounted on a board to connect and integrate a LC filter and a built-in LC filter. The mounting area of the filter can be reduced, and the size and weight can be reduced. Also, cost reduction can be realized.

Further, since the high-frequency switch and the filter can be designed at the same time, the high-frequency switch and the filter can be designed with impedance matching, and the matching circuit becomes unnecessary. Therefore, cost reduction can be realized.

Further, since the low-temperature fired ceramic substrate is used as the multilayer substrate, the plurality of dielectric layers and the electrodes forming the transmission lines and the capacitors on the plurality of dielectric layers can be integrally fired. Therefore, the manufacturing process can be shortened, and the cost can be reduced.

The circuit diagrams of the high-frequency switch shown in FIGS. 3, 10, 12, and 13 and the top and bottom views of the dielectric layers constituting the multilayer substrate shown in FIG. 5 are examples. Anything consisting of a diode mounted on a multilayer substrate, and a transmission line and a capacitor built in the multilayer substrate can be said to be within the scope of the present invention.

The circuit diagram of the LC filter shown in FIG. 4 is an example, and it can be said that the circuit diagram is within the scope of the present invention as long as it includes a transmission line and a capacitor built in a multilayer substrate.

Further, the case where the combination of the SAW filter and the LC filter is a band-pass filter and a low-pass filter has been described. However, another combination such as a band-pass filter and a band-pass filter may be used.

Also, a case has been described in which a material mainly containing barium oxide, aluminum oxide, and silica is used for the low-temperature fired ceramic substrate. In addition, barium oxide, silica, strontium oxide, and zirconium oxide are mainly used. It is also possible to use materials, calcium zirconium oxide, materials mainly composed of glass, and the like.

Further, the transmission line is a strip line,
Consists of microstrip lines, coplanar guidelines, etc. When the wavelength of the high-frequency signal flowing through the high-frequency switch is λ, the length is λ / 4 or less due to the influence of the inductance of the transmission line and the stray capacitance.

[0048]

According to the high frequency device of the first aspect, a SAW filter is mounted on a multilayer substrate formed by laminating a plurality of dielectric layers constituting a high frequency switch having at least four ports, and the high frequency switch and the SAW filter are provided. , The mounting area of the high-frequency switch and the SAW filter in the printed wiring board can be reduced, and the size and weight can be reduced. Also, cost reduction can be realized.

According to the high frequency device of the second aspect, a SAW filter is mounted on a multilayer substrate formed by laminating a plurality of dielectric layers constituting a high frequency switch having at least four ports, and further, an LC filter is incorporated. For integration, the overall size is further reduced as compared to a conventional discrete high frequency switch and filter mounted on a substrate and connected. Therefore, further reduction in size and weight of the high-frequency device can be realized.

Further, the high-frequency switch and the filter can be designed simultaneously, and the high-frequency switch and the filter can be designed with impedance matching, and the matching circuit is not required. Therefore, cost reduction can be realized.

According to the third aspect of the present invention, since the low-temperature-fired ceramic substrate is used for the multilayer substrate, the plurality of dielectric layers and the electrodes forming the transmission lines and the capacitors on the plurality of dielectric layers are formed. Can be integrally fired. Therefore, the manufacturing process can be shortened, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a high-frequency device according to the present invention.

FIG. 2 is a schematic circuit diagram of a high-frequency switch included in the high-frequency device of FIG.

FIG. 3 is a circuit diagram of the high-frequency switch of FIG. 2;

FIG. 4 is a circuit diagram of an LC filter constituting the high-frequency device of FIG. 1;

FIG. 5 is a top view of (a) a first dielectric layer to (h) an eighth dielectric layer of the multilayer substrate constituting the high-frequency device of FIG. 1;

6 is a top view of (a) a ninth dielectric layer to (h) a sixteenth dielectric layer of the multilayer substrate constituting the high-frequency device of FIG. 1;

FIGS. 7A and 7B are top views of (a) a seventeenth dielectric layer to (c) a nineteenth dielectric layer of the multilayer substrate constituting the high-frequency device of FIG. 1, and (d) a lower surface of the nineteenth dielectric layer. FIG.

FIG. 8 is a block diagram of a second embodiment of the high-frequency device according to the present invention.

9 is a schematic circuit diagram of a high-frequency switch included in the high-frequency device of FIG.

FIG. 10 is a circuit diagram of the high-frequency switch of FIG. 9;

FIG. 11 is another schematic circuit diagram of a high-frequency switch constituting the high-frequency device of FIG. 8;

FIG. 12 is a circuit diagram of the high-frequency switch of FIG. 11;

FIG. 13 is another circuit diagram of the high-frequency switch of FIG. 11;

FIG. 14 is a block diagram showing a general high-frequency device.

[Explanation of symbols]

10, 20 high frequency devices 11a to 11q, 23a to 23d, 31a to 31g, 4
1a to 41h Capacitors 12a to 12i, 22a to 22d, 33a to 33d, 4
3a to 43d Transmission line a to s Dielectric layer SW10, SW20, SW30, SW31 High frequency switch F11, F21 LC filter F12, F21, F22 SAW filter

Claims (3)

[Claims] A high-frequency switch having at least four ports including a multilayer substrate formed by laminating a plurality of dielectric layers, a diode mounted on the multilayer substrate, and a transmission line and a capacitor built in the multilayer substrate; A high-frequency device comprising: a SAW filter mounted on the multilayer substrate. 2. The high-frequency device according to claim 1, wherein an LC filter including a transmission line and a capacitor is built in the multilayer substrate. 3. The high-frequency device according to claim 1, wherein a low-temperature fired ceramic substrate is used as the multilayer substrate.