Small millimeter wave frequency source

Abstract

The utility model relates to the technical field of active microwaves, in particular to a small millimeter wave frequency source. Comprising a comb spectrum generation unit, a frequency synthesis unit and a frequency multiplication processing unit. A frequency synthesis unit is arranged by adopting a technology of combining direct digital frequency synthesis and a phase-locked loop, miniaturization of a frequency source module is realized through frequency-band synthesis, and millimeter wave signals with sparse stepping, relatively low stray and high stability can be output; and the first switch and the second switch are arranged to be matched for use, so that the switching between the frequency doubling channel and the frequency quadruplicating channel is realized, the output of radio-frequency signals of different working frequency bands is realized, and the frequency conversion device has the advantages of higher frequency resolution, wider output frequency band and higher frequency conversion speed.

Description

Technical Field

[0001] The utility model relates to the technical field of active microwaves, in particular to a small millimeter wave frequency source. Background Art

[0002] Frequency synthesis technology is a technology that uses one or more high-stability crystal oscillators to generate a series of equally spaced, discrete, and highly stable frequencies. Devices and equipment that implement frequency synthesis are called frequency synthesizers, which are one of the important components of modern communication technology and can provide communication equipment with a large number of accurate and rapidly converted carrier signals and local oscillator signals.

[0003] With the development of microwave electronic technology, especially the rapid development of radar technology, the requirements for frequency sources are getting higher and higher. Although there are many design schemes for frequency sources in the existing technology, due to the difficulty in process implementation and the complexity of the scheme, the cost and volume of the final product are also unacceptable.

[0004] There are two common approaches: one is single phase-locked loop frequency synthesis, and the other is direct digital frequency source.

[0005] The single phase-locked loop frequency synthesizer is mainly composed of a reference divider, a phase detector, a loop filter, a voltage-controlled oscillator and a variable divider. The working principle is: after the loop starts working, the signal frequency fi generated by the crystal oscillator is divided by the reference divider to obtain the reference frequency fR, also known as the reference frequency. The output frequency fo of the voltage-controlled oscillator is divided by the variable divider, and then the output frequency fv=fo / N of the variable divider is compared with the reference frequency fR in the phase detector. If the two are different, there will be an inherent frequency difference between the two signals, which will inevitably produce a constantly changing phase difference. The error voltage output by the phase detector will vary within a certain range. Under the control of the error voltage output by the phase detector, the frequency of the voltage-controlled oscillator also changes accordingly. If the output frequency fo of the voltage-controlled oscillator changes so that the output frequency fv of the variable divider is equal to the reference frequency fR, the stability condition is met and the output frequency fo of the voltage-controlled oscillator will stabilize. At this time, the frequency difference between the input signal generated by the crystal oscillator and the output signal of the voltage-controlled oscillator is zero, the phase difference will also be constant, the error voltage output by the phase detector remains unchanged, and the loop enters the "locked" state.

[0006] However, although a single phase-locked loop frequency synthesizer can realize frequency synthesis, when the variable frequency division ratio is large, the output noise is also large. Moreover, a single phase-locked loop frequency synthesizer needs to reduce the reference frequency or increase the frequency division ratio of the frequency divider to achieve a higher frequency resolution, that is, a single phase-locked loop frequency synthesizer has a contradiction between high reference frequency, low frequency division ratio and high resolution. In the field of frequency synthesis technology, people often hope to use a signal with a higher reference frequency and a frequency divider with a lower frequency division ratio to synthesize a frequency with a large bandwidth, high resolution and low phase noise.

[0007] In traditional frequency source design, the frequency conversion speed has reached its limit, and it also has problems such as low resolution and poor spurious suppression. The current design of frequency sources is developing towards low phase noise, high spectrum purity, agile frequency change, small step, and wide frequency band. Utility Model Content

[0008] Aiming at the problem that the frequency conversion speed of the existing frequency source has been close to the limit and also has the problems of low resolution and poor spurious suppression, the utility model proposes a small millimeter wave frequency source; a reference harmonic signal is generated by setting a comb spectrum generating unit; a frequency synthesis unit is set to generate a radio frequency reference signal according to the reference harmonic signal; and a frequency multiplication processing unit is set to generate a radio frequency signal according to the radio frequency reference signal; while realizing the miniaturization of the frequency source module, it realizes the output of a radio frequency signal with sparse steps, low spurious and high stability.

[0009] The specific implementation contents of the utility model are as follows:

[0010] A small millimeter wave frequency source, comprising a comb spectrum generating unit, a frequency synthesis unit, and a frequency multiplication processing unit;

[0011] The input end of the frequency synthesis unit is connected to the output end of the comb spectrum generation unit, and the output end of the frequency synthesis unit is connected to the input end of the frequency multiplication processing unit;

[0012] The output end of the frequency multiplication processing unit outputs a radio frequency signal;

[0013] The comb spectrum generating unit is used to generate a reference harmonic signal;

[0014] The frequency synthesis unit is used to generate a radio frequency reference signal according to the reference harmonic signal;

[0015] The frequency multiplication processing unit is used to generate a radio frequency signal according to the radio frequency reference signal.

[0016] In order to better implement the utility model, further, the frequency synthesis unit includes a direct digital frequency synthesizer and a phase-locked loop controller;

[0017] The input end of the direct digital frequency synthesizer is connected to the output end of the comb spectrum generating unit, and the output end of the direct digital frequency synthesizer is connected to the input end of the phase-locked loop controller;

[0018] The output end of the phase-locked loop controller is connected to the input end of the frequency multiplication processing unit;

[0019] The direct digital frequency synthesizer is used to generate a small step signal according to the reference harmonic signal;

[0020] The phase-locked loop controller is used to generate a radio frequency reference signal corresponding to the working frequency band according to the working frequency band.

[0021] In order to better implement the utility model, further, the frequency synthesis unit also includes a first bandpass filter and a low noise amplifier;

[0022] The input end of the first bandpass filter is connected to the output end of the phase-locked loop controller, and the output end of the first bandpass filter is connected to the input end of the low noise amplifier;

[0023] The output end of the low noise amplifier is connected to the input end of the frequency multiplication processing unit.

[0024] In order to better realize the utility model, further, the comb spectrum generating unit includes a constant temperature crystal oscillator, a comb spectrum generator, and a surface acoustic wave filter;

[0025] The input end of the comb spectrum generator is connected to the output end of the oven-controlled crystal oscillator, and the output end of the comb spectrum generator is connected to the output end of the surface acoustic wave filter;

[0026] The output end of the SAW filter is connected to the input end of the direct digital frequency synthesizer;

[0027] The constant temperature crystal oscillator is used to generate a crystal oscillator reference signal;

[0028] The comb spectrum generator is used to generate an original harmonic signal according to the crystal oscillator reference signal;

[0029] The SAW filter is used to filter out the original harmonic signal to obtain a reference harmonic signal.

[0030] In order to better implement the utility model, further, the frequency multiplication processing unit includes a first switch, a doubler, a quadrupler, and a second switch;

[0031] The input end of the first switch is connected to the output end of the low noise amplifier, the first output end of the first switch is connected to the input end of the frequency doubler, and the second output end of the first switch is connected to the input end of the frequency quadrupler;

[0032] The first input end of the second switch is connected to the output end of the frequency doubler, the second input end of the second switch is connected to the output end of the frequency quadrupler, and the output end of the second switch outputs a radio frequency signal corresponding to the radio frequency reference signal.

[0033] In order to better implement the utility model, further, the frequency multiplication processing unit also includes a second band-pass filter and a third band-pass filter;

[0034] The input end of the second band-pass filter is connected to the output end of the frequency doubler, and the output end of the second band-pass filter is connected to the first input end of the second switch;

[0035] The input end of the third band-pass filter is connected to the output end of the frequency quadrupler, and the output end of the third band-pass filter is connected to the second input end of the second switch.

[0036] In order to better implement the utility model, further, the small millimeter wave frequency source also includes a control and communication unit;

[0037] The output end of the control and communication unit is connected to the controlled end of the comb spectrum generating unit, the controlled end of the frequency synthesis unit, and the controlled end of the frequency multiplication processing unit.

[0038] In order to better implement the utility model, further, the small millimeter wave frequency source also includes a power supply unit;

[0039] The output end of the power supply unit is connected to the input end of the comb spectrum generating unit, the input end of the frequency synthesis unit, the input end of the frequency multiplication processing unit, and the input end of the control and communication unit.

[0040] The utility model has the following beneficial effects:

[0041] (1) The utility model adopts the technology of combining direct digital frequency synthesis with a phase-locked loop; the frequency-band synthesis realizes the miniaturization of the frequency source module and can output millimeter-wave signals with sparse steps, low spurious and high stability.

[0042] (2) The utility model realizes the switching of the double frequency path and the quadruple frequency path by setting the first switch and the second switch for use together, thereby realizing the output of radio frequency signals in different working frequency bands, and has the advantages of higher frequency resolution, wider output frequency band and faster frequency conversion speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The utility model provides a schematic block diagram of the overall structure.

[0044] Figure 2This is a schematic diagram of the specific structure provided by the utility model. DETAILED DESCRIPTION

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. It should be understood that the described embodiments are only part of the embodiments of the utility model, not all of the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technical personnel in this field without creative work are within the scope of protection of the utility model.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] Embodiment 1:

[0048] This embodiment proposes a small millimeter wave frequency source, such as Figure 1 As shown, it includes a comb spectrum generating unit, a frequency synthesis unit, and a frequency multiplication processing unit;

[0049] The input end of the frequency synthesis unit is connected to the output end of the comb spectrum generation unit, and the output end of the frequency synthesis unit is connected to the input end of the frequency multiplication processing unit;

[0050] The output end of the frequency multiplication processing unit outputs a radio frequency signal;

[0051] The comb spectrum generating unit is used to generate a reference harmonic signal;

[0052] The frequency synthesis unit is used to generate a radio frequency reference signal according to the reference harmonic signal;

[0053] The frequency multiplication processing unit is used to generate a radio frequency signal according to the radio frequency reference signal.

[0054] Working principle: This embodiment generates a reference harmonic signal by setting a comb spectrum generating unit; setting a frequency synthesis unit to generate a radio frequency reference signal according to the reference harmonic signal; and setting a frequency multiplication processing unit to generate a radio frequency signal according to the radio frequency reference signal; while realizing the miniaturization of the frequency source module, it realizes the output radio frequency signal with sparse steps, lower spurious and high stability.

[0055] Embodiment 2:

[0056] This embodiment is based on the above embodiment 1. Figure 2 As shown, the specific structure of the comb spectrum generating unit is explained.

[0057] The comb spectrum generating unit comprises a constant temperature crystal oscillator, a comb spectrum generator and a surface acoustic wave filter;

[0058] The input end of the comb spectrum generator is connected to the output end of the oven-controlled crystal oscillator, and the output end of the comb spectrum generator is connected to the output end of the surface acoustic wave filter;

[0059] The output end of the SAW filter is connected to the input end of the direct digital frequency synthesizer;

[0060] The constant temperature crystal oscillator is used to generate a crystal oscillator reference signal;

[0061] The comb spectrum generator is used to generate an original harmonic signal according to the crystal oscillator reference signal;

[0062] The SAW filter is used to filter out the original harmonic signal to obtain a reference harmonic signal.

[0063] Working principle: The comb spectrum generating unit of this embodiment includes a constant temperature crystal oscillator for generating a crystal reference signal; a comb spectrum generator for generating a customized original harmonic signal through the input crystal reference signal; and a surface acoustic wave filter for filtering out-of-band spurious signals of the original harmonic signal to obtain a reference harmonic signal.

[0064] The other parts of this embodiment are the same as those of the above-mentioned embodiment 1, and thus will not be described in detail.

[0065] Embodiment 3:

[0066] This embodiment is based on any one of the above embodiments 1 to 2. Figure 2 As shown, the specific structure of the frequency synthesis unit is described in detail.

[0067] The frequency synthesis unit includes a direct digital frequency synthesizer and a phase-locked loop controller;

[0068] The input end of the direct digital frequency synthesizer is connected to the output end of the comb spectrum generating unit, and the output end of the direct digital frequency synthesizer is connected to the input end of the phase-locked loop controller;

[0069] The output end of the phase-locked loop controller is connected to the input end of the frequency multiplication processing unit;

[0070] The direct digital frequency synthesizer is used to generate a small step signal according to the reference harmonic signal;

[0071] The phase-locked loop controller is used to generate a radio frequency reference signal corresponding to the working frequency band according to the working frequency band.

[0072] Furthermore, the frequency synthesis unit further includes a first bandpass filter and a low noise amplifier;

[0073] The input end of the first bandpass filter is connected to the output end of the phase-locked loop controller, and the output end of the first bandpass filter is connected to the input end of the low noise amplifier;

[0074] The output end of the low noise amplifier is connected to the input end of the frequency multiplication processing unit.

[0075] Working principle: The frequency synthesis unit proposed in this embodiment includes a direct digital frequency synthesizer, which is used to generate a small step signal with a bandwidth not less than the bandwidth of the reference harmonic signal based on a reference harmonic signal; a phase-locked loop circuit with an integrated VCO, which is used to generate a first RF reference signal required by a first frequency band and a second RF reference signal required by a second frequency band different from the first frequency band; a first bandpass filter, which is used to filter out spurious signals other than the first RF reference signal and the second RF reference signal; and a low noise amplifier, which is used to amplify the power of the first RF reference signal and the second RF reference signal.

[0076] The other parts of this embodiment are the same as any of the above-mentioned embodiments 1-2, so they will not be repeated here.

[0077] Embodiment 4:

[0078] This embodiment is based on any one of the above embodiments 1 to 3. Figure 2 As shown, the structure of the frequency multiplication processing unit is described in detail.

[0079] The frequency multiplication processing unit includes a first switch, a frequency doubler, a frequency quadrupler, and a second switch;

[0080] The input end of the first switch is connected to the output end of the low noise amplifier, the first output end of the first switch is connected to the input end of the frequency doubler, and the second output end of the first switch is connected to the input end of the frequency quadrupler;

[0081] The first input end of the second switch is connected to the output end of the frequency doubler, the second input end of the second switch is connected to the output end of the frequency quadrupler, and the output end of the second switch outputs a radio frequency signal corresponding to the radio frequency reference signal.

[0082] In order to better implement the utility model, further, the frequency multiplication processing unit also includes a second band-pass filter and a third band-pass filter;

[0083] The input end of the second band-pass filter is connected to the output end of the frequency doubler, and the output end of the second band-pass filter is connected to the first input end of the second switch;

[0084] The input end of the third band-pass filter is connected to the output end of the frequency quadrupler, and the output end of the third band-pass filter is connected to the second input end of the second switch.

[0085] Working principle: The frequency multiplication processing unit proposed in this embodiment includes: a first RF switch, which is used to switch the first RF reference signal to the double frequency path, and switch the second RF reference signal to the quadruple frequency path.

[0086] The frequency doubling path includes: a frequency doubler for doubling the frequency of the first RF reference signal to generate a first RF signal; and a second bandpass filter for filtering the first RF signal to remove high-frequency spurious signals caused by the frequency doubling.

[0087] The quadrupling path includes: a quadrupler for quadrupling the second RF reference signal to generate a second RF signal; and a third bandpass filter for filtering the second RF signal to remove high-frequency spurious generated by the quadrupling.

[0088] Furthermore, the frequency multiplication processing unit includes: a second radio frequency switch for switching the output of the first radio frequency signal or the second radio frequency signal in the double frequency path or the quadruple frequency path.

[0089] When the frequency source module outputs the first RF signal of the first frequency band, the quadruple frequency path of the frequency source module is powered off, and the double frequency path is in working state. The frequency source module generates a custom original harmonic signal by inputting the crystal oscillator reference signal generated by the constant temperature crystal oscillator into the comb spectrum generator; the original harmonic signal then enters the SAW filter to filter out the out-of-band spurious signals to obtain the reference harmonic signal. The reference harmonic signal will enter the direct digital frequency synthesizer to generate a small step signal with a bandwidth not less than the bandwidth of the reference harmonic signal; the small step signal will be input into the phase-locked loop circuit of the integrated VCO as a reference signal to generate the first RF reference signal required for the first frequency band; the generated first RF reference signal will be filtered out of the spurious signals other than the first RF reference signal through the first bandpass filter; the first RF reference signal after filtering is amplified by the low noise amplifier. The first RF reference signal is switched to the double frequency path by the cooperation of the first switch and the second switch. In the double frequency path, the double frequency and filtering functions of the first RF reference signal are completed, and finally the first RF signal of the first frequency band is output through the second switch.

[0090] When the frequency source module outputs the second RF signal of the second frequency band, the double frequency path of the frequency source module is powered off, and the quadruple frequency path is in working state. The frequency source module generates a custom original harmonic signal by inputting the crystal oscillator reference signal generated by the constant temperature crystal oscillator into the comb spectrum generator; the original harmonic signal then enters the SAW filter to filter out the out-of-band spurious signals to obtain the reference harmonic signal. The reference harmonic signal will enter the direct digital frequency synthesizer to generate a small step signal with a bandwidth not less than the bandwidth of the reference harmonic signal; the small step signal will be input into the phase-locked loop circuit of the integrated VCO as a reference signal to generate the second RF reference signal required for the second frequency band; the generated second RF reference signal will be filtered out of the spurious signals other than the second RF reference signal through the first bandpass filter; the second RF reference signal after filtering is amplified by the low noise amplifier. The second RF reference signal is switched to the quadruple frequency path by the cooperation of the first switch and the second switch. In the quadruple frequency path, the quadruple frequency and filtering functions of the second RF reference signal are completed, and finally the second RF signal of the second frequency band is output through the second switch.

[0091] The comb spectrum generating unit generates a 1GHz reference signal and outputs it to the frequency synthesizing unit. The frequency synthesizing unit generates X-band and Ku-band radio frequency signals. The frequency multiplication processing unit outputs a millimeter wave radio frequency signal. The present invention adopts a technology combining direct digital frequency synthesis with a phase-locked loop and a frequency division synthesis method to achieve the miniaturization of the frequency source module and output a millimeter wave signal with sparse steps, low spurious and high stability.

[0092] The other parts of this embodiment are the same as any one of the above-mentioned embodiments 1 to 3, so they will not be repeated here.

[0093] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A small millimeter wave frequency source, It is characterized in that It includes a comb spectrum generating unit, a frequency synthesis unit, and a frequency multiplication processing unit; The input end of the frequency synthesis unit is connected to the output end of the comb spectrum generation unit, and the output end of the frequency synthesis unit is connected to the input end of the frequency multiplication processing unit; The output end of the frequency multiplication processing unit outputs a radio frequency signal; The comb spectrum generating unit is used to generate a reference harmonic signal; The frequency synthesis unit is used to generate a radio frequency reference signal according to the reference harmonic signal; The frequency multiplication processing unit is used to generate a radio frequency signal according to the radio frequency reference signal.

2. A small millimeter wave frequency source according to claim 1, It is characterized in that The frequency synthesis unit includes a direct digital frequency synthesizer and a phase-locked loop controller; The input end of the direct digital frequency synthesizer is connected to the output end of the comb spectrum generating unit, and the output end of the direct digital frequency synthesizer is connected to the input end of the phase-locked loop controller; The output end of the phase-locked loop controller is connected to the input end of the frequency multiplication processing unit; The direct digital frequency synthesizer is used to generate a small step signal according to the reference harmonic signal; The phase-locked loop controller is used to generate a radio frequency reference signal corresponding to the working frequency band according to the working frequency band.

3. A small millimeter wave frequency source according to claim 2, It is characterized in that The frequency synthesis unit also includes a first bandpass filter and a low noise amplifier; The input end of the first bandpass filter is connected to the output end of the phase-locked loop controller, and the output end of the first bandpass filter is connected to the input end of the low noise amplifier; The output end of the low noise amplifier is connected to the input end of the frequency multiplication processing unit.

4. A small millimeter wave frequency source according to claim 2, It is characterized in that The comb spectrum generating unit comprises a constant temperature crystal oscillator, a comb spectrum generator and a surface acoustic wave filter; The input end of the comb spectrum generator is connected to the output end of the oven-controlled crystal oscillator, and the output end of the comb spectrum generator is connected to the output end of the surface acoustic wave filter; The output end of the SAW filter is connected to the input end of the direct digital frequency synthesizer; The constant temperature crystal oscillator is used to generate a crystal oscillator reference signal; The comb spectrum generator is used to generate an original harmonic signal according to the crystal oscillator reference signal; The SAW filter is used to filter out the original harmonic signal to obtain a reference harmonic signal.

5. A small millimeter wave frequency source according to claim 3, It is characterized in that The frequency multiplication processing unit includes a first switch, a frequency doubler, a frequency quadrupler, and a second switch; The input end of the first switch is connected to the output end of the low noise amplifier, the first output end of the first switch is connected to the input end of the frequency doubler, and the second output end of the first switch is connected to the input end of the frequency quadrupler; The first input end of the second switch is connected to the output end of the frequency doubler, the second input end of the second switch is connected to the output end of the frequency quadrupler, and the output end of the second switch outputs a radio frequency signal corresponding to the radio frequency reference signal.

6. A small millimeter wave frequency source according to claim 5, It is characterized in that The frequency multiplication processing unit further includes a second band-pass filter and a third band-pass filter; The input end of the second band-pass filter is connected to the output end of the frequency doubler, and the output end of the second band-pass filter is connected to the first input end of the second switch; The input end of the third band-pass filter is connected to the output end of the frequency quadrupler, and the output end of the third band-pass filter is connected to the second input end of the second switch.

7. A small millimeter wave frequency source according to claim 1, It is characterized in that The small millimeter wave frequency source also includes a control and communication unit; The output end of the control and communication unit is connected to the controlled end of the comb spectrum generating unit, the controlled end of the frequency synthesis unit, and the controlled end of the frequency multiplication processing unit.

8. A small millimeter wave frequency source according to claim 7, It is characterized in that The small millimeter wave frequency source also includes a power supply unit; The output end of the power supply unit is connected to the input end of the comb spectrum generating unit, the input end of the frequency synthesis unit, the input end of the frequency multiplication processing unit, and the input end of the control and communication unit.

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