CN220122875U - Ka frequency band millimeter wave up-converter circuit - Google Patents

Abstract

The utility model discloses a Ka frequency band millimeter wave up-converter circuit which comprises an IF/C up-conversion unit, a C/Ka up-conversion unit and a local oscillator unit; the IF/C up-conversion unit is used for realizing up-conversion of the IF signal into a C frequency band radio frequency signal; the C/Ka up-conversion unit is used for up-converting the C frequency band radio frequency signal to a Ka frequency band millimeter wave signal; the local oscillator unit is used for providing local oscillator signals for the IF/C up-conversion unit and the C/Ka up-conversion unit and realizing frequency spectrum shifting of the signals; according to the utility model, through the design of the IF/C up-conversion unit, the design of the C/Ka up-conversion unit and the design of the local oscillator unit, the Ka frequency band broadband up-converter is realized, and the technical indexes of large bandwidth, high flatness and high isolation of the Ka frequency band are realized.

Description

Ka frequency band millimeter wave up-converter circuit

Technical Field

The utility model relates to the technical field of microwave and millimeter wave circuits, in particular to a Ka frequency band millimeter wave up-converter circuit.

Background

The microwave frequency converter is widely applied to the fields of satellite communication, telemetry and remote sensing, radar systems, navigation systems, electronic countermeasure and the like, and is a core component of a modern communication system. Due to the rapid development of the communication industry, the radio frequency front-end circuit has higher and higher integration level, more and more functions and higher frequency, so that the manufacturing difficulty of the equipment is higher and higher. The up-converter is one of the core components of the communication system, and can realize the frequency spectrum shifting from the radio frequency signal to the intermediate frequency signal so as to facilitate the demodulation of the signal. Because of the increasing congestion of channel resources, the traditional S, C, X, ku frequency band frequency converter cannot meet the data transmission of large-flux and large-bandwidth signals, so that the KA frequency band millimeter wave frequency converter needs to be developed, and the KA frequency band millimeter wave frequency converter is a key technology of satellite communication in China, has quite great difficulty in design, such as higher frequency, poorer in-band flatness, serious space leakage and the like, but has the characteristics of high frequency, large information capacity, strong anti-interference capability and the like, and is actively participated and researched by a plurality of scientific research institutes at home and abroad.

Disclosure of Invention

The utility model provides a Ka frequency band millimeter wave up-converter circuit which is mainly applied to a microwave millimeter wave electronic system, such as a cloud satellite, a space monitoring satellite, a space relay satellite, a satellite ground station system, a millimeter wave radar system and the like, and provides a solution for large-flux and large-bandwidth signal data transmission of Ka frequency band satellite communication.

The millimeter wave up-converter circuit with the Ka frequency band comprises an IF/C up-conversion unit, a C/Ka up-conversion unit and a local oscillation unit for providing local oscillation signals, wherein the output end of the IF/C up-conversion unit is electrically connected with the input end of the C/Ka up-conversion unit, the local oscillation unit comprises a point frequency local oscillation subunit and a frequency hopping local oscillation subunit, the point frequency local oscillation subunit is connected with the IF/C up-conversion unit, and the frequency hopping local oscillation subunit is connected with the C/Ka up-conversion unit.

Specifically, the IF/C up-conversion unit includes an intermediate frequency signal IF input end and a C-band intermediate frequency signal IF output end, a mixer MIX1 and a mixer MIX2 that are sequentially connected are disposed between the intermediate frequency signal IF input end and the C-band intermediate frequency signal IF output end, and the mixer MIX1 and the mixer MIX2 are respectively connected to the point frequency local oscillator subunit LO1 and the point frequency local oscillator subunit LO2.

Specifically, a low-pass filter LPF1, a low-noise amplifier AMP1, and a digital attenuator ATT1 connected to the input intermediate frequency signal IF1 are sequentially disposed between the intermediate frequency signal IF input end and the mixer MIX1, and the digital attenuator ATT1 is connected to the low-noise amplifier AMP2 to enter a matching circuit for matching and then connected to the mixer MIX1.

Specifically, a low-pass filter LPF2 is further arranged between the mixer MIX1 and the mixer MIX2, and an L-band intermediate frequency signal IF2 output after mixing by the mixer MIX1 enters a matching circuit to be matched and then is connected to the low-pass filter LPF2; and a numerical control attenuator ATT2, a primary amplifier AMP3 and a band-pass filter BPF1 are further arranged between the low-pass filter LPF2 and the mixer MIX2, the band-pass filter BPF1 is connected with a matching circuit for matching and then is connected with the mixer MIX2, and the other end of the mixer MIX2 is connected with the output end of a C-band intermediate frequency signal IF.

Specifically, the point frequency local oscillator subunit LO1 and the point frequency local oscillator subunit LO2 comprise an integrated phase-locked loop for locking input signals, a band-pass filter for filtering fundamental waves and phase discrimination spurious output point frequency signals, and an amplifier; the frequency division ratio of the programmable frequency divider in the integrated phase-locked loop ring is adjustable.

Specifically, the C/Ka up-conversion unit includes a C-band intermediate frequency signal IF input end and a Ka-band millimeter wave signal output end, where the C-band intermediate frequency signal IF input end and the Ka-band millimeter wave signal output end are provided with a mixer MIX3, and the mixer MIX3 is connected to a frequency hopping local oscillator subunit LO3; and a low-pass filter LPF3 and a low-noise amplifier AMP4 are further arranged between the input end of the C-band intermediate frequency signal IF and the mixer MIX3, the low-noise amplifier AMP4 is connected with a matching circuit for matching and then is connected with a band-pass filter BPF2, and the band-pass filter BPF2 is connected to the mixer MIX3.

Specifically, a switch filter bank is further arranged between the mixer MIX3 and the Ka frequency band millimeter wave signal output end, and the Ka frequency band millimeter wave signal mixed by the mixer MIX3 enters a matching circuit to be matched and then is connected into the switch filter bank; and a first-stage amplifier AMP5, an amplifier AMP6 and an isolator are further arranged between the switch filter bank and the Ka frequency band millimeter wave signal output end.

Specifically, the frequency hopping local oscillator subunit LO3 includes a harmonic generator and two paths of power divisions after two frequency division; the two paths of power branches comprise a DDS clock signal branch and a mixer local oscillator signal branch, the DDS clock signal branch and the mixer local oscillator signal branch are further provided with a mixer and a phase-locked loop, and the phase-locked loop is provided with a phase discriminator with a high normalized noise substrate.

The utility model has the beneficial effects that: the utility model provides a Ka frequency band millimeter wave up-converter circuit which is mainly applied to microwave and millimeter wave electronic systems, such as a cloud satellite, a space monitoring satellite, a space relay satellite, a satellite ground station system, a millimeter wave radar system and the like.

Drawings

Fig. 1 is a circuit diagram of a Ka-band millimeter wave up-converter according to the present utility model;

FIG. 2 is a schematic block diagram of an IF/C up-conversion unit in an embodiment of the utility model;

FIG. 3 is a schematic block diagram of a C/Ka up-conversion unit in an embodiment of the utility model;

fig. 4 is a schematic block diagram of a mid-frequency local oscillator LO1, LO2 according to an embodiment of the present utility model;

fig. 5 is a schematic block diagram of a frequency hopping local oscillator LO3 in an embodiment of the utility model.

Description of the embodiments

For a clearer understanding of technical features, objects, and effects of the present utility model, a specific embodiment of the present utility model will be described with reference to the accompanying drawings.

In one embodiment, as shown in fig. 1, a Ka-band millimeter wave up-converter circuit adopts a superheterodyne circuit structure, adopts a three-time frequency conversion scheme, and comprises an IF/C up-conversion unit, a C/Ka up-conversion unit and a local oscillation unit for providing local oscillation signals, wherein the output end of the IF/C up-conversion unit is electrically connected with the input end of the C/Ka up-conversion unit, the local oscillation unit comprises a point frequency local oscillation subunit and a frequency hopping local oscillation subunit, the point frequency local oscillation subunit is connected with the IF/C up-conversion unit, and the frequency hopping local oscillation subunit is connected with the C/Ka up-conversion unit to realize up-conversion of IF signals to Ka-band millimeter wave signals; a primary numerical control attenuator is adopted to realize the gain adjustment of 0 to 30dB, and the gain is stepped by 0.5dB; the local oscillation scheme of DDS is adopted to realize the frequency hopping stepping of 1 KHz.

In this embodiment, the Ka-band millimeter wave up-converter mainly comprises the following parts: the system comprises an IF/C up-conversion unit design, a local oscillation unit design, an IF/C up-conversion unit, a C/Ka up-conversion unit and a local oscillation unit. The IF/C up-conversion unit is used for realizing up-conversion of the IF signal into a C frequency band radio frequency signal; the C/Ka up-conversion unit is used for up-converting the C frequency band radio frequency signal to a Ka frequency band millimeter wave signal; the local oscillator unit is used for providing local oscillator signals for the IF/C up-conversion unit and the C/Ka up-conversion unit and realizing frequency spectrum shifting of the signals; according to the utility model, through the design of the IF/C up-conversion unit, the design of the C/Ka up-conversion unit and the design of the local oscillator unit, the Ka frequency band broadband up-converter is realized. The Ka frequency band broadband up-converter is realized. The specific technical index requirements are as follows:

input frequency: f1+ -20 MHz;

frequency step: less than or equal to 1kHz;

input standing wave ratio: the ratio of the components is less than or equal to 1.5:1;

output frequency: F2-F3 GHz;

output standing wave ratio: the ratio of the components is less than or equal to 2.0:1;

gain: 40+ -1 dB;

gain adjustment range: 30dB, step 0.5dB;

in-band flatness: less than or equal to +/-0.5 dB/+/-10 MHz;

output spurs: output of more than or equal to 60 dBc@0dBm.

In a preferred embodiment, as shown in fig. 2, the IF/C up-conversion unit includes an intermediate frequency signal IF input end and a C-band intermediate frequency signal IF output end, between which a mixer MIX1 and a mixer MIX2 are arranged, which are sequentially connected, and the mixer MIX1 and the mixer MIX2 are respectively connected to the point frequency local oscillator subunit LO1 and the point frequency local oscillator subunit LO2.

The low-pass filter LPF1, the low-noise amplifier AMP1 and the digital control attenuator ATT1 which are connected with the input intermediate frequency signal IF1 are sequentially arranged between the intermediate frequency signal IF input end and the mixer MIX1, and the digital control attenuator ATT1 is connected with the low-noise amplifier AMP2 and then connected with the mixer MIX1 after being matched with the matching circuit.

A low-pass filter LPF2 is further arranged between the mixer MIX1 and the mixer MIX2, and an L-band intermediate frequency signal IF2 output after the mixer MIX1 mixes is connected to the low-pass filter LPF2 after entering a matching circuit for matching; and a numerical control attenuator ATT2, a primary amplifier AMP3 and a band-pass filter BPF1 are further arranged between the low-pass filter LPF2 and the mixer MIX2, the band-pass filter BPF1 is connected with a matching circuit for matching and then is connected with the mixer MIX2, and the other end of the mixer MIX2 is connected with the output end of a C-band intermediate frequency signal IF.

In this embodiment, the IF/C up-conversion unit mainly performs secondary frequency mixing on an input IF signal, performs filtering, attenuation, amplification and filtering after the frequency mixing, then outputs the mixed signal, enters the mixer MIX3 to perform frequency conversion for three times, up-converts the mixed signal into a millimeter wave signal in the Ka frequency band, and outputs the millimeter wave signal, as shown in fig. 2, sends the input IF signal into the low-pass filter LPF1 to perform filtering, and then sends the filtered signal into the low-noise amplifier AMP1 to perform amplification; then through a 6-bit digital control attenuator ATT1, gain of 0-30 dB can be adjusted, the step is adjusted to 0.5dB, and the gain is sent to a matching circuit for matching; sending the signal into a low-noise amplifier AMP2 for amplification, and then sending the signal into a matching circuit for matching; then sending the mixed signals into a mixer MIX1 and a local oscillation signal LO1 for mixing, outputting an intermediate frequency signal IF2 of an L frequency band after mixing, and sending the intermediate frequency signal IF2 into a matching circuit for matching; then the local oscillation signal LO1 is sent into a low-pass filter LPF2 for filtering, so as to inhibit the leakage of the local oscillation signal LO 1; gain adjustment of 0-30 dB can be realized through a 6-bit numerical control attenuator ATT2, the step is adjusted to be 0.5dB, ATT2 is used for gain compensation, and gain consistency in the full-band range is ensured; amplifying by a first-stage amplifier AMP3, sending the amplified signal into a band-pass filter BPF1 to inhibit out-of-band spurious signals, and then sending the spurious signals into a matching circuit to be matched and then outputting an intermediate frequency signal IF2; the intermediate frequency signal IF2 enters a mixer MIX2 and a local oscillation signal LO2 to be mixed, and the intermediate frequency signal IF3 in the C frequency band is output after the mixing.

In another embodiment, as shown in fig. 3, the C/Ka up-conversion unit includes a C-band intermediate frequency signal IF input end and a Ka-band millimeter wave signal output end, where the C-band intermediate frequency signal IF input end and the Ka-band millimeter wave signal output end are provided with a mixer MIX3, and the mixer MIX3 is connected to the frequency hopping local oscillator subunit LO3; and a low-pass filter LPF3 and a low-noise amplifier AMP4 are further arranged between the input end of the C-band intermediate frequency signal IF and the mixer MIX3, the low-noise amplifier AMP4 is connected with a matching circuit for matching and then is connected with a band-pass filter BPF2, and the band-pass filter BPF2 is connected to the mixer MIX3.

A switch filter bank is further arranged between the mixer MIX3 and the Ka frequency band millimeter wave signal output end, and the Ka frequency band millimeter wave signal mixed by the mixer MIX3 enters a matching circuit to be matched and then is connected into the switch filter bank; and a first-stage amplifier AMP5, an amplifier AMP6 and an isolator are further arranged between the switch filter bank and the Ka frequency band millimeter wave signal output end.

In this embodiment, the C/Ka up-conversion unit mainly amplifies and filters an input C-band signal, then sends the amplified C-band signal to the mixer to perform frequency conversion once, up-converts the C-band signal to a millimeter wave signal of a Ka band, and outputs the millimeter wave signal after filtering and amplifying. As shown in fig. 3, the intermediate frequency signal IF3 in the C frequency band is sent to the low pass filter LPF3 for filtering, to suppress the leakage of the local oscillation signal LO2, and then sent to the low noise amplifier AMP4 for amplification, and then sent to the matching circuit for matching; then sending the local oscillation signal LO2 into a band-pass filter BPF2 for filtering, and inhibiting leakage and combined spurious of the local oscillation signal LO 2; then sending the millimeter wave signals into a matching circuit for matching, then sending the millimeter wave signals into a mixer MIX3 and an LO3 for mixing, up-converting the millimeter wave signals into a Ka frequency band, and then sending the millimeter wave signals into the matching circuit for matching and then outputting the millimeter wave signals; entering a four-section switch filter bank, and carrying out sectional filtering on Ka frequency band millimeter wave signals output after mixing, wherein the sectional filtering is mainly used for inhibiting leakage signals of local oscillation signals LO3 and mixed combined spurious signals; then the amplified signal is sent to a matching circuit for matching after being amplified by a first-stage amplifier AMP5, and then is sent to an amplifier AMP6 for amplification and output; the amplified KA frequency band millimeter wave signal is sent into the isolator, and the standing wave of the output port can be good due to the unidirectional transmission characteristic of the isolator.

In another embodiment, as shown in fig. 4 and 5, the local oscillator unit designs (1) LO1 and LO2: point frequency local oscillator and (2) LO3: frequency hopping local oscillation; the point frequency local oscillation subunit LO1 and the point frequency local oscillation subunit LO2 comprise an integrated phase-locked loop for locking input signals, a band-pass filter for filtering fundamental waves and phase discrimination spurious output point frequency signals and an amplifier; the frequency dividing ratio of the programmable frequency divider in the integrated phase-locked loop ring is adjustable; the frequency hopping local oscillator subunit LO3 comprises a harmonic generator and two paths of power division after frequency division; the two paths of power branches comprise a DDS clock signal branch and a mixer local oscillator signal branch, the DDS clock signal branch and the mixer local oscillator signal branch are further provided with a mixer and a phase-locked loop, and the phase-locked loop is provided with a phase discriminator with a high normalized noise substrate.

In this embodiment, as shown in fig. 4, the dot frequency local oscillators LO1 and LO2 are the working principles of the phase-locked loops of the dot frequency local oscillators LO1 and LO2: the input highly stable and accurate reference signal is locked and then the output frequency N times the reference signal is obtained by changing the frequency dividing ratio N of the programmable divider inside the loop. The point frequency local oscillator adopts an integrated phase-locked loop, outputs a point frequency signal after phase locking and frequency multiplication through the phase-locked loop, filters fundamental waves and phase discrimination spurious signals through a band-pass filter, outputs a required point frequency signal, and outputs the point frequency signal after amplification through an amplifier.

As shown in fig. 5, the frequency hopping local oscillator LO3 operates according to the following principle: the 100MHz signal generates an L frequency band signal through a harmonic generator, the L frequency band signal is divided into two paths after frequency division, one path is used as a clock signal of the DDS, the other path is used as a local oscillation signal of the mixer, and the DDS signal outputs a section of low-spurious intermediate frequency signal. The local oscillation signal and the intermediate frequency signal are subjected to frequency mixing filtering and then divided by four, and the output signal is used as a reference signal of the PLL. The PLL adopts a phase discriminator with a high normalized noise base, the normalized phase noise base is-233 dBc/Hz, the phase discrimination frequency is fpd, the maximum N value can be calculated according to the maximum output frequency of the local oscillator, and the phase noise calculation formula is as follows: PN=floor FOM+10log (fpd) +20log N= -111dBc/Hz (Floor FOM: normalized phase noise Floor of phase detector, 10log (fpd): phase noise due to deterioration of reference frequency, 20log N: phase noise due to deterioration of frequency division ratio), the in-loop theoretical noise can be calculated to be-112 dBc/Hz. The actual phase noise of 10k and 100k is about 5dB worse than the theoretical value, and the phase noise of 1k is about 10dB worse, so that the phase noise can reach-102 dBc/Hz@1kHz,107dBc/Hz@10kHz@100kHz; for a phase-locked loop circuit, phase noise within a loop bandwidth is mainly determined by a phase discriminator, a reference frequency and a frequency division ratio, phase noise outside the loop bandwidth is mainly determined by a VCO, -118dBc/Hz@1MHz@8GHz, and the phase noise can achieve-102 dBc/Hz@1kHz,107dBc/Hz@10kHz@100kHz; and the DDS scheme is adopted, and the frequency hopping step can achieve 1Hz.

The utility model is mainly applied to microwave and millimeter wave electronic systems, such as a cloud satellite, a space monitoring satellite, a space relay satellite, a satellite ground station system, a millimeter wave radar system and the like. The Ka frequency band broadband frequency converter is mainly used for solving the problem of large-flux and large-bandwidth signal data transmission of Ka frequency band satellite communication; meanwhile, the method is widely applied to millimeter wave radar systems, so that the detection distance and detection precision of the radar are greatly improved, and the situation awareness capability of the radar is improved. Through the design of the IF/C up-conversion unit and the design of the C/Ka up-conversion unit, the design of the local oscillator unit, the Ka frequency band millimeter wave up-converter is realized, the technical problems of wide bandwidth, higher frequency, poorer in-band flatness and serious space leakage of the Ka frequency band millimeter wave converter are solved, the technical indexes of large bandwidth, high flatness and high isolation of the Ka frequency band are realized, and a solution is provided for the data transmission of large-flux and large-bandwidth signals of the Ka frequency band satellite communication.

The foregoing has shown and described the basic principles and features of the utility model and the advantages of the utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims. The scope of the utility model is defined by the appended claims and equivalents thereof.

Claims (8)

1. The millimeter wave up-converter circuit with the Ka frequency band is characterized by comprising an IF/C up-conversion unit, a C/Ka up-conversion unit and a local oscillator unit for providing local oscillator signals, wherein the output end of the IF/C up-conversion unit is electrically connected with the input end of the C/Ka up-conversion unit, the local oscillator unit comprises a point frequency local oscillator subunit and a frequency hopping local oscillator subunit, the point frequency local oscillator subunit is connected with the IF/C up-conversion unit, and the frequency hopping local oscillator subunit is connected with the C/Ka up-conversion unit.

2. The Ka-band millimeter wave up-converter circuit according to claim 1, wherein the IF/C up-conversion unit comprises an intermediate frequency signal IF input end and a C-band intermediate frequency signal IF output end, a mixer MIX1 and a mixer MIX2 are sequentially connected between the intermediate frequency signal IF input end and the C-band intermediate frequency signal IF output end, and the mixer MIX1 and the mixer MIX2 are respectively connected to the point frequency local oscillator subunit LO1 and the point frequency local oscillator subunit LO2.

3. The Ka-band millimeter wave up-converter circuit according to claim 2, wherein a low-pass filter LPF1, a low-noise amplifier AMP1 and a digital attenuator ATT1 connected to the intermediate frequency signal IF1 are further sequentially arranged between the intermediate frequency signal IF input terminal and the mixer MIX1, and the digital attenuator ATT1 is connected to the low-noise amplifier AMP2 to enter the matching circuit for matching and then connected to the mixer MIX1.

4. The Ka-band millimeter wave up-converter circuit according to claim 3, wherein a low-pass filter LPF2 is further provided between the mixer MIX1 and the mixer MIX2, and the L-band intermediate frequency signal IF2 output after mixing by the mixer MIX1 enters a matching circuit to be matched and then is connected to the low-pass filter LPF2; and a numerical control attenuator ATT2, a primary amplifier AMP3 and a band-pass filter BPF1 are further arranged between the low-pass filter LPF2 and the mixer MIX2, the band-pass filter BPF1 is connected with a matching circuit for matching and then is connected with the mixer MIX2, and the other end of the mixer MIX2 is connected with the output end of a C-band intermediate frequency signal IF.

5. The Ka-band millimeter wave up-converter circuit of claim 2, wherein said dot frequency local oscillator subunit LO1 and said dot frequency local oscillator subunit LO2 comprise an integrated phase-locked loop for locking input signals, a bandpass filter for filtering fundamental wave and phase-discrimination spurious output dot frequency signals, and an amplifier; the frequency division ratio of the programmable frequency divider in the integrated phase-locked loop ring is adjustable.

6. The Ka-band millimeter wave up-converter circuit according to claim 1, wherein said C/Ka up-conversion unit comprises a C-band intermediate frequency signal IF input and a Ka-band millimeter wave signal output, said C-band intermediate frequency signal IF input and Ka-band millimeter wave signal output being provided with a mixer MIX3, said mixer MIX3 being connected to a frequency hopping local oscillator subunit LO3; and a low-pass filter LPF3 and a low-noise amplifier AMP4 are further arranged between the input end of the C-band intermediate frequency signal IF and the mixer MIX3, the low-noise amplifier AMP4 is connected with a matching circuit for matching and then is connected with a band-pass filter BPF2, and the band-pass filter BPF2 is connected to the mixer MIX3.

7. The Ka-band millimeter wave up-converter circuit according to claim 6, wherein a switch filter bank is further arranged between the mixer MIX3 and the Ka-band millimeter wave signal output end, and the Ka-band millimeter wave signal mixed by the mixer MIX3 enters the matching circuit for matching and then is connected to the switch filter bank; and a first-stage amplifier AMP5, an amplifier AMP6 and an isolator are further arranged between the switch filter bank and the Ka frequency band millimeter wave signal output end.

8. The Ka-band millimeter wave up-converter circuit of claim 6, wherein said frequency hopping local oscillator subunit LO3 comprises a harmonic generator and two divided power components; the two paths of power branches comprise a DDS clock signal branch and a mixer local oscillator signal branch, the DDS clock signal branch and the mixer local oscillator signal branch are further provided with a mixer and a phase-locked loop, and the phase-locked loop is provided with a phase discriminator with a high normalized noise substrate.