CN111987995A - Comb signal source based on mixing modulation feedback loop - Google Patents

Abstract

The invention belongs to the field of electronic communication, and particularly relates to a comb signal source based on a frequency mixing modulation feedback loop. The microwave signal source comprises a local oscillator signal source, a first isolator, a first directional coupler, a first frequency mixer, an intermediate frequency signal source, a first microwave amplifier, a second directional coupler, a second isolator, an output antenna and a second microwave amplifier; the device can simultaneously generate comb-shaped frequency array signals with a plurality of dot frequencies, a loop circuit consisting of an amplifier is added on the basis of double-sideband frequency mixing, and the frequency mixer generates a nonlinear effect through the resonance of the loop circuit, so that the power of a plurality of frequencies is finally basically consistent, a series of frequency array signals are generated, and therefore, the frequency quantity is large, and the flatness of output power is high. The loop uses fewer devices, and therefore is low in cost.

Description

A Comb Signal Source Based on Mixing Modulation Feedback Loop

technical field

The invention belongs to the field of electronic communication, in particular to a comb-shaped signal source.

Background technique

Comb frequency signals have important applications in electronic circuits, radio frequency and other fields, such as phase calibration, spread spectrum, frequency hopping communication or interference, multi-channel detection, etc.

At present, there are mainly three ways to generate the comb frequency signal. The most common one is a tunnel diode, a step recovery diode and other devices. The principle is to use the energy storage element to charge and discharge to generate an ultra-short pulse signal, and then to shape the harmonics of each order. The bandwidth and power consistency of its comb-like signal mainly depend on the inherent characteristics of the diode, which are often difficult to tune. The second way is to use multiple independent microwave sources to synthesize, each frequency point is independent of each other. Since each frequency point can be adjusted individually, good power flatness can be achieved, but phase consistency requires additional processing, and its cost directly increases with the number of channels. The third method is to use a mixer to convert the frequency, and use the nonlinear effect when the local oscillator and the intermediate frequency signal are mixed to generate multiple frequency conversion signals. Among them, the phase difference of the two intermediate frequency signals can be used to adjust the output comb spectrum. power flatness. However, the output comb-like signal characteristics mainly depend on the inherent characteristics of the mixer. Usually, the frequency points are relatively small, the power of high-order harmonic mixing is poor, and the adjustment range of power flatness is also very limited.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a comb-shaped signal source based on a frequency mixing modulation feedback loop, which can output a signal source of multiple frequencies at the same time, and has high power and flatness.

The technical scheme of the present invention is as follows:

A comb-shaped signal source based on a frequency mixing modulation feedback loop, comprising a local oscillator signal source, a first isolator, a first directional coupler, a first mixer, an intermediate frequency signal source, a first microwave amplifier, a second directional signal source a coupler, a second isolator, an output antenna and a second microwave amplifier;

The output end of the local oscillator signal source is connected to the input end of the first isolator, the output end of the first isolator is connected to the input end of the first directional coupler, and the output end of the first directional coupler is connected to the first hybrid The local oscillator end of the frequency mixer is connected to the output end of the intermediate frequency signal source, the output end of the intermediate frequency signal source is connected to the intermediate frequency end of the first mixer, the radio frequency end of the first mixer is connected to the input end of the first microwave amplifier, and the output end of the first microwave amplifier is connected is connected to the input end of the second directional coupler, the coupling end of the second directional coupler is connected to the input end of the second microwave amplifier, the output end of the second microwave amplifier is connected to the coupling end of the first directional coupler, the second The output end of the directional coupler is connected to the input end of the second isolator, and the output end of the second isolator is connected to the input end of the output antenna.

A comb-shaped signal source based on a frequency mixing modulation feedback loop, comprising a local oscillator signal source, a first isolator, a first power divider, a first mixer, an intermediate frequency signal source, a first microwave amplifier, and a second power divider a device, a second isolator, an output antenna and a second microwave amplifier;

The output end of the local oscillator signal source is connected to the input end of the first isolator, the output end of the first isolator is connected to the input end of the first power divider, and the output end of the first power divider is connected to the first mixer The output end of the intermediate frequency signal source is connected to the intermediate frequency end of the first mixer, the radio frequency end of the first mixer is connected to the input end of the first microwave amplifier, and the output end of the first microwave amplifier is connected to the first The input end of the second power divider is connected to the input end of the second power divider, the coupling end of the second power divider is connected to the input end of the second microwave amplifier, the output end of the second microwave amplifier is connected to the coupling end of the first power divider, and the second power divider is connected to the input end of the second microwave amplifier. The output end is connected to the input end of the second isolator, and the output end of the second isolator is connected to the input end of the output antenna.

A comb-shaped signal source based on a frequency mixing modulation feedback loop, comprising a local oscillator signal source, a first isolator, a first power divider, a first mixer, an intermediate frequency signal source, a first microwave amplifier, and a second power divider a power divider, a second isolator, an output antenna and a second microwave amplifier; also include a power division bridge, a second mixer, a radio frequency power divider, a radio frequency power divider and a phase shifter;

Wherein, the output end of the local oscillator signal source is connected with the input end of the first isolator, and the output end of the first isolator is connected with the input end of the first directional coupler;

The output end of the first directional coupler is connected to the input end of the power divider bridge, and the two output ends of the power divider bridge are respectively connected to the local oscillator end of the first mixer and the local oscillator end of the second mixer , a power divider is installed between the first mixer and the intermediate frequency signal source, one of the two output ends of the power divider is connected to the intermediate frequency end of the first mixer, and the other output end of the power divider is connected to the phase shifter. The input end, the output end of the phase shifter is connected with the intermediate frequency end of the second mixer. The radio frequency ends of the first mixer and the second frequency mixer are respectively connected with the input port of the radio frequency power divider, and the output end of the radio frequency power divider is connected with the input end of the first microwave amplifier;

The output end of the first microwave amplifier is connected to the input end of the second directional coupler, the coupling end of the second directional coupler is connected to the input end of the second microwave amplifier, and the output end of the second microwave amplifier is connected to the first directional coupler The coupling end of the second directional coupler is connected to the input end of the second isolator, and the output end of the second isolator is connected to the input end of the output antenna.

A comb-shaped signal source based on a frequency mixing modulation feedback loop, comprising a local oscillator signal source, a first isolator, a first power divider, a first mixer, an intermediate frequency signal source, a first microwave amplifier, and a second power divider a power divider, a second isolator, an output antenna and a second microwave amplifier; also include a power division bridge, a second mixer, a radio frequency power divider, a radio frequency power divider and a frequency multiplier;

Wherein, the output end of the local oscillator signal source is connected with the input end of the first isolator, and the output end of the first isolator is connected with the input end of the first directional coupler;

The output end of the first directional coupler is connected to the input end of the power divider bridge, and the two output ends of the power divider bridge are respectively connected to the local oscillator end of the first mixer and the local oscillator end of the second mixer , a power divider is installed between the first mixer and the intermediate frequency signal source, one of the two output ends of the power divider is connected to the intermediate frequency end of the first mixer, and the other output end of the power divider is connected to the frequency multiplier The input end, the output end of the frequency multiplier is connected with the intermediate frequency end of the second mixer. The radio frequency ends of the first mixer and the second frequency mixer are respectively connected with the input port of the radio frequency power divider, and the output end of the radio frequency power divider is connected with the input end of the first microwave amplifier;

The output end of the first microwave amplifier is connected to the input end of the second directional coupler, the coupling end of the second directional coupler is connected to the input end of the second microwave amplifier, and the output end of the second microwave amplifier is connected to the first directional coupler The coupling end of the second directional coupler is connected to the input end of the second isolator, and the output end of the second isolator is connected to the input end of the output antenna.

The significant effects of the present invention are as follows: the device can simultaneously generate comb-shaped frequency array signals with multiple point frequencies. Compared with the prior art, a loop loop composed of an amplifier is added on the basis of double-sideband mixing. Through the resonance of the loop loop, the mixer produces a nonlinear effect, so that the power of multiple frequencies is basically the same. A series of frequency array signals are generated, so the number of frequencies is large and the flatness of the output power is high. The circuit uses fewer components, so the cost is low. In addition, the signal source is determined by the external input local oscillator and intermediate frequency, and it is relatively easy to adjust the frequency interval and quantity.

Description of drawings

1 is a schematic diagram of a first embodiment of a comb-shaped signal source based on a frequency mixing modulation feedback loop;

2 is a schematic diagram of a second embodiment of a comb-shaped signal source based on a frequency mixing modulation feedback loop;

In the figure: 1. Local oscillator signal source; 2. The first isolator; 3. The first directional coupler; 4. The first mixer; 5. The intermediate frequency signal source; 6. The first microwave amplifier; 7. The first Two directional couplers; 8. Second isolator; 9. Output antenna; 10. Second microwave amplifier; 11. Power divider bridge; 12. RF power divider; 13. Intermediate frequency power divider; Frequency converter; 15. Phase shifter.

Detailed ways

The present invention will be further described below through the accompanying drawings and specific embodiments.

In the description of the following components, the so-called "first" and "second" do not represent any logical sequence relationship, but are only used to distinguish two identical components included in the system.

One embodiment of the present invention as shown in Figure 1 is:

The output end of the local oscillator signal source 1 is connected to the input end of the first isolator 2 , the output end of the first isolator 2 is connected to the input end of the first directional coupler 3 , and the output end of the first directional coupler 3 is connected to The local oscillator end of the first mixer 4 is connected, the output end of the intermediate frequency signal source 5 is connected to the intermediate frequency end of the first mixer 4, and the radio frequency end of the first mixer 4 is connected to the input end of the first microwave amplifier 6 , the output end of the first microwave amplifier 6 is connected to the input end of the second directional coupler 7, the coupling end of the second directional coupler 7 is connected to the input end of the second microwave amplifier 10, and the output end of the second microwave amplifier 10 is connected to The coupling end of the first directional coupler 3 is connected, the output end of the second directional coupler 7 is connected to the input end of the second isolator 8 , and the output end of the second isolator 8 is connected to the input end of the output antenna 9 .

The local oscillator signal source 1 and the intermediate frequency signal source 5 are point frequency signal sources, and their power is required to be sufficient to drive the first mixer 4, and the value is generally 10-16dBm.

The first isolator 2 is used to prevent microwaves generated by the frequency mixing loop from being transmitted to the local oscillator signal source 1, and plays a protective role, and has no direct impact on the generation of the comb-shaped signal in the feedback loop.

The feedback loop based on frequency mixing modulation includes a first directional coupler 3 , a first mixer 4 , signal amplifiers 6 , 10 and a second directional coupler 7 . The first directional coupler 3 synthesizes the loop feedback signal and the external signal and sends it to the first mixer 4; The frequency conversion signal of the frequency difference is not limited to the upper/lower single sideband mixing, double sideband mixing or more complicated frequency conversion structure; the function of the first microwave amplifier 6 is to amplify the output of the first mixer 4, It determines the power of the final output comb signal; the function of the second directional coupler 7 is to derive the signal of the loop as the final output, and generate a signal for feedback, which requires high isolation between the two outputs of the device The device for realizing this function is not limited to a directional coupler, for example, a power divider can be used to achieve the same function; the function of the second microwave amplifier 10 is to amplify the feedback signal and send it to the input end of the power combiner, in order to make the power of the feedback signal sufficient To drive the mixer to work, the requirement of its saturation power gain is related to the drive power of the first mixer 4 and the second mixer 14, the saturation power is 19-21dBm, and the power gain is related to the loop loss, usually 20- 30dB.

The second isolator 8 is used to prevent microwaves from being reflected by the peripheral system, which affects the multiple feedback loops, thereby affecting the output frequency and power. In order to reduce the influence of the external system on the signal source, the isolation is usually required to be 20-30dB.

The working mode of the feedback loop is as follows: the point frequency signal output by the local oscillator signal source 1 reaches the input end of the first mixer 4 through the first isolator 2 and the first directional coupler 3 as the local oscillator signal, and the intermediate frequency signal source 5 The output point frequency signal is input to the intermediate frequency input terminal of the first mixer 4. According to the working mode of the mixer, the output frequency of the first mixer 4 includes double sideband frequency conversion or harmonic frequency conversion, etc. The first mixer 4. The output frequency conversion signal is amplified by the second directional coupler 7 and a part of the power is coupled to the second microwave amplifier 10 for amplification, and finally combined with the point frequency signal of the local oscillator signal source 1 in the first directional coupler 3, Thus a loop composed of mixers and amplifiers is formed.

The simplification of the feedback loop is understood as: after the loop starts to work, the output signal of the first directional coupler 3 combined through the loop will have multiple frequency points, and the first mixer 4 will have multiple frequency points for these multiple frequencies. The frequency is then mixed to generate frequency expansion to the high-order wave, thereby generating a comb-shaped frequency array signal with the frequency of the local oscillator signal 1 as the center and the frequency of the intermediate frequency signal 5 as the interval. The center reference frequency of the comb signal is determined by the local oscillator signal source 1 , the frequency interval of the comb signal is determined by the intermediate frequency signal source 5 , and the output power of the comb signal is mainly determined by the first microwave amplifier 6 .

The total gain of the first microwave amplifier 6 and the second microwave amplifier 10 needs to be greater than the total loss of the entire feedback loop, and the total loop loss includes the frequency conversion loss of the mixer, the coupling degree of the directional coupler, the insertion loss of the connecting line, etc. , in order to ensure the stable and reliable operation of the system, the total gain of the first microwave amplifier 6 and the second microwave amplifier 10 is greater than the total loss by 5-10 dB.

The output number and power distribution of the comb-shaped frequency array signal are mainly determined by the response of the amplifier and the loop to each frequency. The flatness of the comb-shaped signal is mainly determined by the characteristics of the first mixer 4, and the frequency bandwidth of the comb-shaped signal is mainly determined by the operating frequency bands of all devices in the feedback loop. Generally, a band-pass filter can be added in the feedback loop to limit The bandwidth of the comb signal, the filter can be added between any two components of the loop, such as between the first mixer 4 and the first microwave amplifier 6, or between the microwave amplifier 6 and the second directional coupler 7 between.

Based on the basis of Embodiment 1, the comb signal source based on the frequency mixing modulation feedback loop of the present invention can also be changed to a composite structure as shown in FIG. 2 to further improve the power division flatness and distribution of the comb signal. FIG. 2 shows a schematic structural diagram of a comb frequency signal source using a composite frequency conversion structure in the second embodiment of the present invention.

As shown in FIG. 2 , a power divider bridge 11 , a second mixer 14 , a radio frequency power divider 13 and a radio frequency power divider 12 are added to the feedback loop of Embodiment 1. That is, the output end of the first directional coupler 3 is connected to the input end of the power division bridge 11, and the two output ends of the power division bridge 11 are respectively connected to the local oscillator end of the first mixer 4 and the second mixer The local oscillator end of 14 is connected, a power divider 13 is installed between the first mixer 4 and the intermediate frequency signal source 5, and one of the two output ends of the power divider 13 is connected to the intermediate frequency end of the first mixer 4, and the power divider The other output end of the mixer 13 is connected to the input end of the phase shifter 15 , and the output end of the phase shifter 15 is connected to the intermediate frequency end of the second mixer 14 . The radio frequency terminals of the first mixer 4 and the second mixer 14 are respectively connected to the input ports of the radio frequency power divider 12 , and the output terminal of the radio frequency power divider 12 is connected to the input terminal of the first microwave amplifier 6 .

The power dividing bridge 11 can be a quadrature bridge or an angle-adjustable bridge. The intermediate frequency signal 5 is divided into one signal by the power divider 13 to the phase shifter 15 , and finally output to the intermediate frequency input end of the second mixer 14 . By adjusting the phase angle of the power division bridge 11 and the phase shifter 15, the power flatness of the comb frequency array signal can be adjusted.

Embodiment In FIG. 2 , the phase shifter 15 can also be replaced by a frequency multiplier for outputting the higher harmonics of the intermediate frequency signal 5 to the second mixer 14 to expand the number of frequencies of the output comb signal.

The present invention has been described in detail above in conjunction with the accompanying drawings and implementation, but the present invention is not limited to the above-mentioned embodiments, and within the scope of knowledge possessed by those of ordinary skill in the art, various Variety. In addition to the microwave frequency band, this technology can also be used in other radio frequency signal segments. The comb-shaped multi-beam signal source of the invention can be used in various microwave section and radio frequency section systems, especially for military and civil applications such as microwave reflection, radar measurement, and communication.

Claims (10)

1. A comb-shaped signal source based on a frequency mixing modulation feedback loop, characterized in that: comprising a local oscillator signal source (1), a first isolator (2), a first directional coupler (3), a first mixing frequency converter (4), intermediate frequency signal source (5), first microwave amplifier (6), second directional coupler (7), second isolator (8), output antenna (9) and second microwave amplifier (10) ); The output end of the local oscillator signal source (1) is connected to the input end of the first isolator (2), the output end of the first isolator (2) is connected to the input end of the first directional coupler (3), and the first isolator (2) output end is connected to the input end of the first directional coupler (3). The output end of the directional coupler (3) is connected to the local oscillator end of the first mixer (4), the output end of the intermediate frequency signal source (5) is connected to the intermediate frequency end of the first mixer (4), and the first The radio frequency end of a mixer (4) is connected to the input end of the first microwave amplifier (6), the output end of the first microwave amplifier (6) is connected to the input end of the second directional coupler (7), and the second directional The coupling end of the coupler (7) is connected to the input end of the second microwave amplifier (10), the output end of the second microwave amplifier (10) is connected to the coupling end of the first directional coupler (3), and the second directional coupling The output end of the isolator (7) is connected to the input end of the second isolator (8), and the output end of the second isolator (8) is connected to the input end of the output antenna (9). 2. a kind of comb-shaped signal source based on frequency mixing modulation feedback loop as claimed in claim 1 is characterized in that: described local oscillator signal source (1) and intermediate frequency signal source (5) are point frequency signal sources, The power range is 10-16dBm. 3 . The comb-shaped signal source based on the frequency mixing modulation feedback loop according to claim 1 , wherein the power gain of the second microwave amplifier ( 10 ) is 20-30 dB. 4 . 4 . The comb-shaped signal source based on the frequency mixing modulation feedback loop according to claim 1 , wherein the isolation degree of the second isolator ( 8 ) is 20-30 dB. 5 . 5. A comb-shaped signal source based on a frequency mixing modulation feedback loop, characterized in that: it comprises a local oscillator signal source (1), a first isolator (2), a first power divider, and a first mixer (4). ), an intermediate frequency signal source 5, a first microwave amplifier (6), a second power divider, a second isolator (8), an output antenna (9) and a second microwave amplifier (10); Wherein, the output end of the local oscillator signal source (1) is connected with the input end of the first isolator (2), the output end of the first isolator (2) is connected with the input end of the first power divider, and the first power divider The output end of the first mixer (4) is connected to the local oscillator end of the first mixer (4), the output end of the intermediate frequency signal source (5) is connected to the intermediate frequency end of the first mixer (4), and the output end of the first mixer (4) The radio frequency end is connected to the input end of the first microwave amplifier (6), the output end of the first microwave amplifier (6) is connected to the input end of the second power divider, and the coupling end of the second power divider is connected to the second microwave amplifier ( 10) is connected to the input end, the output end of the second microwave amplifier (10) is connected to the coupling end of the first power divider, the output end of the second power divider is connected to the input end of the second isolator (8), and the second power divider is connected to the input end of the second isolator (8). The output end of the isolator (8) is connected to the input end of the output antenna (9). 6. A kind of comb-shaped signal source based on frequency mixing modulation feedback loop as claimed in claim 5, it is characterized in that: described local oscillator signal source (1) and intermediate frequency signal source (5) are point frequency signal sources, The power range is 10 ~ 16dBm. 7 . The comb-shaped signal source based on the frequency mixing modulation feedback loop according to claim 5 , wherein the power gain of the second microwave amplifier ( 10 ) is 20-30 dB. 8 . 8 . The comb-shaped signal source based on the frequency mixing modulation feedback loop according to claim 5 , wherein the isolation degree of the second isolator ( 8 ) is 20-30 dB. 9 . 9. A comb-shaped signal source based on a frequency mixing modulation feedback loop, characterized in that it comprises a local oscillator signal source (1), a first isolator (2), a first power divider, and a first mixer (4). ), an intermediate frequency signal source (5), a first microwave amplifier (6), a second power divider, a second isolator (8), an output antenna (9) and a second microwave amplifier (10); it also includes a power divider a bridge (11), a second mixer (14), a radio frequency power divider (13), a radio frequency power divider (12) and a phase shifter (15); Wherein, the output end of the local oscillator signal source (1) is connected with the input end of the first isolator (2), and the output end of the first isolator (2) is connected with the input end of the first directional coupler (3); The output end of the first directional coupler (3) is connected with the input end of the power division bridge (11), and the two output ends of the power division bridge (11) are respectively connected with the local oscillator of the first mixer (4). The terminal is connected to the local oscillator terminal of the second mixer (14). A power divider (13) is installed between the first mixer (4) and the intermediate frequency signal source (5). One of the output ends is connected to the intermediate frequency end of the first mixer (4), the other output end of the power divider (13) is connected to the input end of the phase shifter (15), and the output end of the phase shifter (15) is connected to the first The intermediate frequency terminal of the second mixer (14) is connected. The radio frequency ends of the first mixer (4) and the second frequency mixer (14) are respectively connected to the input ports of the radio frequency power divider (12), and the output end of the radio frequency power divider (12) is connected to the first microwave amplifier ( 6) Input terminal connection; The output end of the first microwave amplifier (6) is connected to the input end of the second directional coupler (7), the coupling end of the second directional coupler (7) is connected to the input end of the second microwave amplifier (10), and the second directional coupler (7) is connected to the input end of the second microwave amplifier (10). The output end of the microwave amplifier (10) is connected with the coupling end of the first directional coupler (3), the output end of the second directional coupler (7) is connected with the input end of the second isolator (8), and the second isolator The output end of (8) is connected to the input end of the output antenna (9). 10. A comb-shaped signal source based on a frequency mixing modulation feedback loop, characterized in that it comprises a local oscillator signal source (1), a first isolator (2), a first power divider, and a first mixer (4). ), an intermediate frequency signal source (5), a first microwave amplifier (6), a second power divider, a second isolator (8), an output antenna (9) and a second microwave amplifier (10); it also includes a power divider a bridge (11), a second mixer (14), a radio frequency power divider (13), a radio frequency power divider (12) and a frequency multiplier; Wherein, the output end of the local oscillator signal source (1) is connected with the input end of the first isolator (2), and the output end of the first isolator (2) is connected with the input end of the first directional coupler (3); The output end of the first directional coupler (3) is connected with the input end of the power division bridge (11), and the two output ends of the power division bridge (11) are respectively connected with the local oscillator of the first mixer (4). The terminal is connected to the local oscillator terminal of the second mixer (14). A power divider (13) is installed between the first mixer (4) and the intermediate frequency signal source (5). One of the output ends is connected to the intermediate frequency end of the first mixer (4), the other output end of the power divider (13) is connected to the input end of the frequency multiplier, and the output end of the frequency multiplier is connected to the second frequency mixer (14). ) of the IF side connection. The radio frequency ends of the first mixer (4) and the second frequency mixer (14) are respectively connected to the input ports of the radio frequency power divider (12), and the output end of the radio frequency power divider (12) is connected to the first microwave amplifier ( 6) Input terminal connection; The output end of the first microwave amplifier (6) is connected to the input end of the second directional coupler (7), the coupling end of the second directional coupler (7) is connected to the input end of the second microwave amplifier (10), and the second directional coupler (7) is connected to the input end of the second microwave amplifier (10). The output end of the microwave amplifier (10) is connected with the coupling end of the first directional coupler (3), the output end of the second directional coupler (7) is connected with the input end of the second isolator (8), and the second isolator The output end of (8) is connected to the input end of the output antenna (9).

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