Multi-channel radio frequency receiver applying comb spectrum calibration

Abstract

The utility model provides a multi-channel radio frequency receiver applying comb spectrum calibration, which relates to the technical field of radio frequency receivers, and comprises a multi-channel radio frequency receiving module used for realizing a selection function, a filtering function, an attenuation function, a gain amplification function and a frequency conversion function; the local oscillator module is used for signal frequency conversion to obtain a reference signal; and the calibration source module is used for mixing the reference signal and the high-frequency signal to obtain the required broadband frequency. According to the utility model, the problem that the consistency calibration of the amplitude and the phase in the radio frequency channel in the wide frequency band range can delay the time efficiency of direction finding is solved.

Description

Technical Field

[0001] The utility model relates to the field of radio frequency receivers, and particularly relates to a multi-channel radio frequency receiver applying comb spectrum calibration. Background Art

[0002] In the field of radio frequency receiver technology, the calibration technology mainly realizes the auxiliary of the direction finding process of electromagnetic signals, aiming to calibrate the amplitude and phase consistency in the radio frequency channel, thereby improving the accuracy of the direction finding result of electromagnetic signals. In the conventional calibration process, in order to achieve consistency, a calibration method similar to the point frequency signal is adopted. If this calibration method is applied in a wide frequency band range, it will delay the direction finding efficiency. To solve the above problems, a multi-channel radio frequency receiver applying comb spectrum calibration is specially developed. Content of the Utility Model

[0003] Aiming at the above deficiencies in the prior art, the multi-channel radio frequency receiver applying comb spectrum calibration provided by the utility model solves the problem that the calibration of the amplitude and phase consistency in the radio frequency channel in a wide frequency band range will delay the direction finding efficiency.

[0004] In order to achieve the above utility model purpose, the technical solution adopted by the utility model is: a multi-channel radio frequency receiver applying comb spectrum calibration, including:

[0005] The local oscillator module, including a first local oscillator unit and a second local oscillator unit, is used for signal frequency conversion to obtain a reference signal;

[0006] The calibration source module is used for mixing the reference signal with the high-frequency signal to obtain the required broadband frequency.

[0007] The beneficial effect of the utility model is: by using the multi-channel radio frequency receiver applying comb spectrum calibration, the performance indexes of frequency multipliers, filters, mixers, amplifiers and digital controlled attenuators in the link can be considered, so that the calibration source can have a small noise coefficient, certain gain, ensure the purity of the spectrum, and can work stably for a long time.

[0008] Further, the local oscillator module includes a first local oscillator unit and a second local oscillator unit:

[0009] The first local oscillator unit includes a first phase-locked loop PLL1, a first frequency multiplier, a first attenuator, a first low-pass filter, a second attenuator and a first amplifier; wherein, one end of the first phase-locked loop PLL1 is connected to one end of the first frequency multiplier, the other end of the first frequency multiplier is connected to one end of the first attenuator, the other end of the first attenuator is connected to one end of the first low-pass filter, the other end of the first low-pass filter is connected to one end of the second attenuator, the other end of the second attenuator is connected to one end of the first amplifier, and the other end of the first amplifier is connected to the calibration source module;

[0010] The second local oscillator unit includes a second phase-locked loop PLL2, a first switch, a second frequency multiplier, a third attenuator, a second low-pass filter, a fourth attenuator, a third frequency multiplier, a fifth attenuator, a third low-pass filter, a sixth attenuator, a fourth frequency multiplier, a fourth low-pass filter, a second switch, and a second amplifier. One end of the second phase-locked loop PLL2 is connected to the first contact of the first switch. The second contact of the first switch is connected to one end of the second frequency multiplier. The other end of the second frequency multiplier is connected to one end of the third attenuator. The other end of the third attenuator is connected to one end of the second low-pass filter. The other end of the second low-pass filter is connected to one end of the fourth attenuator. The other end of the fourth attenuator is connected to the second contact of the second switch. The third contact of the first switch is connected to one end of the third frequency multiplier. The other end of the third frequency multiplier is connected to one end of the fifth attenuator. The other end of the fifth attenuator is connected to one end of the third low-pass filter. The other end of the third low-pass filter is connected to one end of the sixth attenuator. The other end of the sixth attenuator is connected to one end of the fourth frequency multiplier. The other end of the fourth frequency multiplier is connected to one end of the fourth low-pass filter. The other end of the fourth low-pass filter is connected to the third contact of the second switch. The first contact of the second switch is connected to one end of the second amplifier. The other end of the second amplifier is connected to the calibration source module.

[0011] Further, both the first phase-locked loop PLL1 and the second phase-locked loop PLL2 include:

[0012] A crystal oscillator, a single-channel DDS-GM4704B, an active loop filter, a voltage-controlled oscillator - VCO, an electrically tunable BPF, a third amplifier, a twelfth attenuator - 3dB, a first low-pass filter, a frequency divider - 4 - frequency division, a fourth amplifier, a thirteenth attenuator - 3dB, and a power divider. One end of the crystal oscillator is connected to one end of the single-channel DDS. The other end of the single-channel DDS is respectively connected to one end of the active loop filter and one end of the low-pass filter. The other end of the active loop filter is connected to one end of the voltage-controlled oscillator. The other end of the voltage-controlled oscillator is connected to one end of the electrically tunable BPF. The other end of the electrically tunable BPF is connected to one end of the third amplifier. The other end of the third amplifier is connected to one end of the twelfth attenuator. The other end of the low-pass filter is connected to one end of the frequency divider. The other end of the frequency divider is connected to one end of the fourth amplifier. The other end of the fourth amplifier is connected to one end of the thirteenth attenuator. One end of the power divider is respectively connected to the other end of the twelfth attenuator and the other end of the thirteenth attenuator. The other end of the power divider serves as the output end of the phase-locked loop.

[0013] Further, the calibration source module includes:

[0014] Comb-shaped spectrum generator, fifth low-pass filter, fifth amplifier, first mixing device, seventh attenuator, sixth low-pass filter, sixth amplifier, second mixing device, third switch, seventh low-pass filter, eighth attenuator, seventh amplifier, ninth attenuator, eighth amplifier, eighth low-pass filter, tenth attenuator, ninth amplifier, eleventh attenuator, and tenth amplifier; wherein, one end of the comb-shaped spectrum generator is connected to one end of the fifth low-pass filter, the other end of the fifth low-pass filter is connected to one end of the fifth amplifier, the other end of the fifth amplifier and a first local oscillator unit are respectively connected to one end of the first mixing device, the other end of the first mixing device is connected to one end of the seventh attenuator, the other end of the seventh attenuator is connected to one end of the sixth low-pass filter, the other end of the sixth low-pass filter is connected to one end of the sixth amplifier, the other end of the sixth amplifier and a second local oscillator unit are respectively connected to one end of the second mixing device, the other end of the second mixing device is connected to the first contact of the third switch, the second contact of the third switch is connected to one end of the seventh low-pass filter, the other end of the seventh low-pass filter is connected to one end of the eighth attenuator, the other end of the eighth attenuator is connected to one end of the seventh amplifier, the other end of the seventh amplifier is connected to one end of the ninth attenuator, the other end of the ninth attenuator is connected to one end of the eighth amplifier, the other end of the eighth amplifier serves as the first output end, the third contact of the third switch is connected to one end of the eighth low-pass filter, the other end of the eighth low-pass filter is connected to one end of the tenth attenuator, the other end of the tenth attenuator is connected to one end of the ninth amplifier, the other end of the ninth amplifier is connected to one end of the eleventh attenuator, the other end of the eleventh attenuator is connected to one end of the tenth amplifier, and the other end of the tenth amplifier serves as the second output end. Description of the Drawings

[0015] This specification will be further described by way of exemplary embodiments, which will be described in detail through the drawings. These embodiments are not restrictive. In these embodiments, the same numbers represent the same structures, where:

[0016] Figure 1 is an exemplary schematic diagram of a multi-channel radio frequency receiver applying comb-shaped spectrum calibration according to some embodiments of this specification;

[0017] Figure 2 is an exemplary schematic diagram of the structures of the first phase-locked loop and the second phase-locked loop according to some embodiments of this specification. Detailed Implementation Modes

[0018] The following describes the specific embodiments of the present utility model to facilitate those skilled in the art of this technology to understand the present utility model. However, it should be clear that the present utility model is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present utility model defined and determined by the appended claims, these changes are obvious, and all utility models created using the concept of the present utility model are within the scope of protection.

[0019] Embodiment

[0020] Figure 1 is an exemplary schematic diagram of a multi-channel radio frequency receiver applying comb spectrum calibration shown according to some embodiments of this specification.

[0021] In some embodiments, the multi-channel radio frequency receiver applying comb spectrum calibration may include a local oscillator module and a calibration source module.

[0022] In some embodiments, the multi-channel radio frequency receiver applying comb spectrum calibration can be used to implement functions such as formula selection, filtering, attenuation, gain amplification, and frequency conversion.

[0023] The local oscillator module includes a first local oscillator unit and a second local oscillator unit.

[0024] In some embodiments, the first local oscillator unit includes a first phase-locked loop PLL1, a first frequency multiplier, a first attenuator, a first low-pass filter, a second attenuator, and a first amplifier; wherein, one end of the first phase-locked loop PLL1 is connected to one end of the first frequency multiplier, the other end of the first frequency multiplier is connected to one end of the first attenuator, the other end of the first attenuator is connected to one end of the first low-pass filter, the other end of the first low-pass filter is connected to one end of the second attenuator, the other end of the second attenuator is connected to one end of the first amplifier, and the other end of the first amplifier is connected to the calibration source module.

[0025] In some embodiments, the second local oscillator unit includes a second phase-locked loop PLL2, a first switch, a second frequency multiplier, a third attenuator, a second low-pass filter, a fourth attenuator, a third frequency multiplier, a fifth attenuator, a third low-pass filter, a sixth attenuator, a fourth frequency multiplier, a fourth low-pass filter, a second switch, and a second amplifier; wherein, one end of the second phase-locked loop PLL2 is connected to the first contact of the first switch, the second contact of the first switch is connected to one end of the second frequency multiplier, the other end of the second frequency multiplier is connected to one end of the third attenuator, the other end of the third attenuator is connected to one end of the second low-pass filter, the other end of the second low-pass filter is connected to one end of the fourth attenuator, the other end of the fourth attenuator is connected to the second contact of the second switch, the third contact of the first switch is connected to one end of the third frequency multiplier, the other end of the third frequency multiplier is connected to one end of the fifth attenuator, the other end of the fifth attenuator is connected to one end of the third low-pass filter, the other end of the third low-pass filter is connected to one end of the sixth attenuator, the other end of the sixth attenuator is connected to one end of the fourth frequency multiplier, the other end of the fourth frequency multiplier is connected to one end of the fourth low-pass filter, the other end of the fourth low-pass filter is connected to the third contact of the second switch, the first contact of the second switch is connected to one end of the second amplifier, and the other end of the second amplifier is connected to the calibration source module.

[0026] In some embodiments, as Figure 2 shown, the first phase-locked loop PLL1 and the second phase-locked loop PLL2 both include: a crystal oscillator, a single-channel DDS-GM4704B, an active loop filter, a voltage-controlled oscillator - VCO, an electrically tunable BPF, a third amplifier, a twelfth attenuator - 3dB, a first low-pass filter, a frequency divider - 4-divider, a fourth amplifier, a thirteenth attenuator - 3dB, and a power splitter; wherein, one end of the crystal oscillator is connected to one end of the single-channel DDS, the other end of the single-channel DDS is respectively connected to one end of the active loop filter and one end of the low-pass filter, the other end of the active loop filter is connected to one end of the voltage-controlled oscillator, the other end of the voltage-controlled oscillator is connected to one end of the electrically tunable BPF, the other end of the electrically tunable BPF is connected to one end of the third amplifier, the other end of the third amplifier is connected to one end of the twelfth attenuator, the other end of the low-pass filter is connected to one end of the frequency divider, the other end of the frequency divider is connected to one end of the fourth amplifier, the other end of the fourth amplifier is connected to one end of the thirteenth attenuator, one end of the power splitter is respectively connected to the other end of the twelfth attenuator and the other end of the thirteenth attenuator, and the other end of the power splitter serves as the output end of the phase-locked loop.

[0027] The calibration source module includes a comb spectrum generator, a fifth low-pass filter, a fifth amplifier, a first mixing device, a seventh attenuator, a sixth low-pass filter, a sixth amplifier, a second mixing device, a third switch, a seventh low-pass filter, an eighth attenuator, a seventh amplifier, a ninth attenuator, an eighth amplifier, an eighth low-pass filter, a tenth attenuator, a ninth amplifier, an eleventh attenuator, and a tenth amplifier.

[0028] In some embodiments, one end of the comb spectrum generator is connected to one end of the fifth low-pass filter, the other end of the fifth low-pass filter is connected to one end of the fifth amplifier, the other end of the fifth amplifier and a first local oscillator unit are respectively connected to one end of the first mixing device, the other end of the first mixing device is connected to one end of the seventh attenuator, the other end of the seventh attenuator is connected to one end of the sixth low-pass filter, the other end of the sixth low-pass filter is connected to one end of the sixth amplifier, the other end of the sixth amplifier and a second local oscillator unit are respectively connected to one end of the second mixing device, the other end of the second mixing device is connected to the first contact of the third switch, the second contact of the third switch is connected to one end of the seventh low-pass filter, the other end of the seventh low-pass filter is connected to one end of the eighth attenuator, the other end of the eighth attenuator is connected to one end of the seventh amplifier, the other end of the seventh amplifier is connected to one end of the ninth attenuator, the other end of the ninth attenuator is connected to one end of the eighth amplifier, the other end of the eighth amplifier serves as the first output end, the third contact of the third switch is connected to one end of the eighth low-pass filter, the other end of the eighth low-pass filter is connected to one end of the tenth attenuator, the other end of the tenth attenuator is connected to one end of the ninth amplifier, the other end of the ninth amplifier is connected to one end of the eleventh attenuator, the other end of the eleventh attenuator is connected to one end of the tenth amplifier, and the other end of the tenth amplifier serves as the second output end.

[0029] In some embodiments, the comb spectrum signal can be composed of multiple frequency points evenly distributed on the frequency axis, covering a wider frequency band range and improving the accuracy of the direction finding result.

[0030] Circuit working principle: Before each direction finding function runs, the comb spectrum generator of the calibration source module first generates a calibration signal, which is calibrated using the fifth low-pass filter and the fifth amplifier. After calibration, the calibration signal is mixed with the signal output by the first local oscillator unit using the first mixer. The local oscillator module generates an 840 MHz signal using a comb spectrum generator, and through frequency multiplication, filtering, and amplification processing by the first frequency multiplier, the first attenuator, the first low-pass filter, the second attenuator, and the first amplifier, the signal output by the first local oscillator unit is obtained. After the first mixing with the first local oscillator unit, a 20 GHz point frequency signal is generated. Then, after the filtering and amplification processing of this point frequency signal by the seventh attenuator, the sixth low-pass filter, and the sixth amplifier, it is mixed with the second local oscillator unit for the second time, and finally, a comb spectrum signal of 30 MHz - 18 GHz is output in two paths. The first path passes through the seventh low-pass filter, the eighth attenuator, the seventh amplifier, the ninth attenuator, and the eighth amplifier to obtain the first output signal, and the other path passes through the eighth low-pass filter, the tenth attenuator, the ninth amplifier, the eleventh attenuator, and the tenth amplifier to obtain the second output signal. Since the local oscillator module needs to perform two mixings, two phase-locked loops are required to provide the local oscillator frequency. The maximum output frequency of the phase-locked loop chip can only be 16 GHz, so frequency multiplication, filtering, and amplification processing are also required on the local oscillator link. In the first mixing, first, an FPGA + DA method is used to generate a fixed 840 MHz comb spectrum signal with a bandwidth greater than 80 MHz, and then this signal is mixed with the first local oscillator for the first time. The first local oscillator generates a 10.42 GHz point frequency signal using the phase-locked loop chip, and after frequency multiplication, filtering, and amplification, it gets 20.84 GHz, and then is mixed with the 840 MHz comb spectrum signal to obtain a 20 GHz signal. The second local oscillator signal is generated in two segments by the phase-locked loop, which are 10 GHz - 14 GHz and 7 GHz - 12 GHz respectively. Then, using the second phase-locked loop PLL2, the first switch, the second frequency multiplier, the third attenuator, the second low-pass filter, the fourth attenuator, the third frequency multiplier, the fifth attenuator, the third low-pass filter, the sixth attenuator, the fourth frequency multiplier, the fourth low-pass filter, the second switch, and the second amplifier, frequency multiplication, filtering, and amplification processing are carried out to meet the required mixing requirements, and finally, the required broadband frequency is obtained.

[0031] Beneficial effects: By using a multi-channel radio frequency receiver with comb spectrum calibration, performance indicators such as frequency multipliers, filters, mixers, amplifiers, and digital control attenuators in the link can be considered, enabling the calibration source to have a small noise coefficient, a certain gain, ensuring the purity of the spectrum, and being able to work stably for a long time.

Claims

1. A multi-channel radio frequency receiver applying comb spectrum calibration, characterized in that, Comprising: An oscillator module, including a first oscillator unit and a second oscillator unit, for signal frequency conversion to obtain a reference signal; The oscillator module includes: The first oscillator unit includes a first phase-locked loop PLL1, a first frequency multiplier, a first attenuator, a first low-pass filter, a second attenuator, and a first amplifier; wherein, one end of the first phase-locked loop PLL1 is connected to one end of the first frequency multiplier, the other end of the first frequency multiplier is connected to one end of the first attenuator, the other end of the first attenuator is connected to one end of the first low-pass filter, the other end of the first low-pass filter is connected to one end of the second attenuator, the other end of the second attenuator is connected to one end of the first amplifier, and the other end of the first amplifier is connected to the calibration source module; The second oscillator unit includes a second phase-locked loop PLL2, a first switch, a second frequency multiplier, a third attenuator, a second low-pass filter, a fourth attenuator, a third frequency multiplier, a fifth attenuator, a third low-pass filter, a sixth attenuator, a fourth frequency multiplier, a fourth low-pass filter, a second switch, and a second amplifier; wherein, one end of the second phase-locked loop PLL2 is connected to the first contact of the first switch, the second contact of the first switch is connected to one end of the second frequency multiplier, the other end of the second frequency multiplier is connected to one end of the third attenuator, the other end of the third attenuator is connected to one end of the second low-pass filter, the other end of the second low-pass filter is connected to one end of the fourth attenuator, the other end of the fourth attenuator is connected to the second contact of the second switch, the third contact of the first switch is connected to one end of the third frequency multiplier, the other end of the third frequency multiplier is connected to one end of the fifth attenuator, the other end of the fifth attenuator is connected to one end of the third low-pass filter, the other end of the third low-pass filter is connected to one end of the sixth attenuator, the other end of the sixth attenuator is connected to one end of the fourth frequency multiplier, the other end of the fourth frequency multiplier is connected to one end of the fourth low-pass filter, the other end of the fourth low-pass filter is connected to the third contact of the second switch, the first contact of the second switch is connected to one end of the second amplifier, and the other end of the second amplifier is connected to the calibration source module; A calibration source module, for mixing the reference signal with a high-frequency signal to obtain the required broadband frequency.

2. The multi-channel RF receiver calibrated by using a comb spectrum according to claim 1, wherein Both the first phase-locked loop PLL1 and the second phase-locked loop PLL2 include: A crystal oscillator, a single-channel DDS-GM4704B, an active loop filter, a voltage-controlled oscillator - VCO, an electronically tunable BPF, a third amplifier, a twelfth attenuator - 3dB, a first low-pass filter, a frequency divider - 4 - frequency division, a fourth amplifier, a thirteenth attenuator - 3dB, and a power splitter; wherein, one end of the crystal oscillator is connected to one end of the single-channel DDS, the other end of the single-channel DDS is respectively connected to one end of the active loop filter and one end of the low-pass filter, the other end of the active loop filter is connected to one end of the voltage-controlled oscillator, the other end of the voltage-controlled oscillator is connected to one end of the electronically tunable BPF, the other end of the electronically tunable BPF is connected to one end of the third amplifier, the other end of the third amplifier is connected to one end of the twelfth attenuator, the other end of the low-pass filter is connected to one end of the frequency divider, the other end of the frequency divider is connected to one end of the fourth amplifier, the other end of the fourth amplifier is connected to one end of the thirteenth attenuator, one end of the power splitter is respectively connected to the other end of the twelfth attenuator and the other end of the thirteenth attenuator, and the other end of the power splitter serves as the output end of the phase-locked loop.

3. The multi-channel radio frequency receiver calibrated by using a comb spectrum according to claim 1, wherein The calibration source module includes: A comb spectrum generator, a fifth low-pass filter, a fifth amplifier, a first mixing device, a seventh attenuator, a sixth low-pass filter, a sixth amplifier, a second mixing device, a third switch, a seventh low-pass filter, an eighth attenuator, a seventh amplifier, a ninth attenuator, an eighth amplifier, an eighth low-pass filter, a tenth attenuator, a ninth amplifier, an eleventh attenuator, and a tenth amplifier; wherein, one end of the comb spectrum generator is connected to one end of the fifth low-pass filter, the other end of the fifth low-pass filter is connected to one end of the fifth amplifier, the other end of the fifth amplifier and the first local oscillator unit are respectively connected to one end of the first mixing device, the other end of the first mixing device is connected to one end of the seventh attenuator, the other end of the seventh attenuator is connected to one end of the sixth low-pass filter, the other end of the sixth low-pass filter is connected to one end of the sixth amplifier, the other end of the sixth amplifier and the second local oscillator unit are respectively connected to one end of the second mixing device, the other end of the second mixing device is connected to the first contact of the third switch, the second contact of the third switch is connected to one end of the seventh low-pass filter, the other end of the seventh low-pass filter is connected to one end of the eighth attenuator, the other end of the eighth attenuator is connected to one end of the seventh amplifier, the other end of the seventh amplifier is connected to one end of the ninth attenuator, the other end of the ninth attenuator is connected to one end of the eighth amplifier, the other end of the eighth amplifier serves as the first output end, the third contact of the third switch is connected to one end of the eighth low-pass filter, the other end of the eighth low-pass filter is connected to one end of the tenth attenuator, the other end of the tenth attenuator is connected to one end of the ninth amplifier, the other end of the ninth amplifier is connected to one end of the eleventh attenuator, the other end of the eleventh attenuator is connected to one end of the tenth amplifier, and the other end of the tenth amplifier serves as the second output end.

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