A low intermediate frequency receiver and a radio frequency signal receiving method

Abstract

The application provides a low intermediate frequency receiver and a radio frequency signal receiving method. The low intermediate frequency receiver comprises a plurality of identical receiving links and a signal modulation module. Each receiving link comprises a radio frequency signal receiving processing module, a power division module and a combination module. The radio frequency signal receiving processing module pre-processes a radio frequency signal. The power division module divides the pre-processed radio frequency signal into a plurality of power division signals, transmits a preset proportion of the plurality of power division signals to the combination module, and transmits the remaining power division signals to the combination module of an adjacent receiving link. The combination module combines the preset proportion of the plurality of power division signals and the remaining power division signals transmitted by the adjacent receiving link to obtain a combination signal, transmits the combination signal to a frequency conversion module for frequency conversion to obtain a target modulation signal, and transmits the target modulation signal to the signal modulation module for demodulation to complete radio frequency signal transmission. The application realizes the use of true diversity technology to divide and combine radio frequency signals and then output modulation, thereby guaranteeing the reliability of radio frequency signal transmission.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radio frequency signal transmission technology, and in particular to a low intermediate frequency receiver and a radio frequency signal receiving method. BACKGROUND

[0002] The low intermediate frequency receiver is an architecture of a radio frequency receiver, which converts the received radio frequency signal to a lower intermediate frequency first, and then completes subsequent processing through digital signal processing. In the field of signal transmission, the performance of the low intermediate frequency receiver in the terminal usually directly determines the quality of the received signal, and how to guarantee the reliability of the low intermediate frequency receiver signal transmission becomes a key problem to be studied at present.

[0003] At present, the technical means adopted by the prior art is usually that after the low intermediate frequency receiver receives the intermediate frequency signal through a single antenna, the signal is amplified by a low noise amplifier and directly enters a frequency conversion mixer driven by a quadrature local oscillator signal to obtain I / Q two low intermediate frequency signals. The intermediate frequency signal includes a useful signal and an image signal, and the frequency of the image signal is very close to that of the useful signal. After passing through the frequency conversion mixer, a complex bandpass filter is needed to amplify the useful signal and suppress the image signal. The complex bandpass filter receives the I and Q signals at the same time, performs complex filtering by using the phase characteristics of the signals, and uses the phase of the I and Q signals to make the positive and negative frequencies asymmetric to realize amplifying the useful signal and suppressing the image signal, effectively suppress the image interference, and finally quantize the intermediate frequency signal through an ADC analog-to-digital converter. However, the prior art adopts single antenna reception when the radio frequency signal is input, and does not pay attention to the fact that the single antenna reception method is easily affected by multipath effect and causes signal interruption, thereby causing the problem of poor radio frequency transmission reliability. SUMMARY

[0004] In order to solve the above problems, the present application proposes a low intermediate frequency receiver and a radio frequency signal receiving method, which realizes the use of true diversity technology to split and combine the radio frequency signal and then output modulation, thereby guaranteeing the reliability of the radio frequency signal transmission.

[0005] To achieve the above object, the embodiment of the present application provides a low intermediate frequency receiver, comprising: a plurality of completely same receiving links and a signal modulation module, any one receiving link comprising: a radio frequency signal receiving processing module, a power division module, a combination module and a frequency conversion module; the first end of the radio frequency signal receiving processing module is electrically connected with the first end of the power division module; the second end of the power division module is electrically connected with the first end of the combination module, and the second end of the combination module is electrically connected with the first end of the frequency conversion module; the third end of the power division module is also electrically connected with the third end of the combination module of the adjacent receiving link; the third end of the combination module is also electrically connected with the third end of the power division module of the adjacent receiving link; the second end of the frequency conversion module is electrically connected with the signal modulation module; the radio frequency signal receiving processing module is used for pre-processing the initial radio frequency signal received in advance to obtain a pre-processed radio frequency signal, and transmitting the pre-processed radio frequency signal to the power division module; the power division module is used for dividing the pre-processed radio frequency signal into a plurality of power division signals, transmitting a plurality of power division signals with a preset proportion to the combination module, and transmitting the remaining plurality of power division signals to the combination module of the adjacent receiving link; the combination module is used for combining the plurality of power division signals with the preset proportion and the remaining plurality of power division signals transmitted by the adjacent receiving link to obtain a combination signal, and transmitting the combination signal to the frequency conversion module; the frequency conversion module is used for frequency conversion processing the combination signal to obtain a target modulation signal, and transmitting the target modulation signal to the signal modulation module; and the signal modulation module is used for demodulating the target modulation signal to complete the radio frequency signal transmission.

[0006] The embodiment of the present application provides a low intermediate frequency receiver, which is provided with a plurality of completely same receiving links, and is provided with a radio frequency signal receiving processing module, a power division module, a combination module and a frequency conversion module in each receiving link, wherein the radio frequency signal receiving processing module pre-processes the received radio frequency signal, the power division module performs diversity on the pre-processed radio frequency signal, the combination module combines the power division signals after diversity to obtain a combination signal, through the cooperative work of the power division module and the combination module, when a receiving link fails, the continuous transmission of the signal can still be ensured through the cooperation of other receiving links, and finally the combination signal is sent to the signal modulation module after frequency conversion by the frequency conversion module for demodulation, so as to complete the transmission of the radio frequency signal. Therefore, through the design of the overall architecture of the multiple receiving links combined with the local diversity design of the power division module and the combination module, the low intermediate frequency receiver is no longer paralyzed due to single point failure, and the reliability of the radio frequency signal transmission is ensured.

[0007] Further, the radio frequency signal receiving and processing module comprises a receiving antenna, a band-pass filter, a detection and comparison unit and a signal amplifier; a first end of the receiving antenna is electrically connected with the transmitter; a second end of the receiving antenna is electrically connected with a first end of the band-pass filter; a second end of the band-pass filter is electrically connected with a first end of the detection and comparison unit; a second end of the detection and comparison unit is electrically connected with a first end of the signal amplifier; a second end of the signal amplifier is electrically connected with the power division module; the radio frequency signal receiving and processing module is used for pre-processing the initially received radio frequency signal to obtain a pre-processed radio frequency signal, and transmitting the pre-processed radio frequency signal to the power division module, comprising: the receiving antenna is used for receiving the initially received radio frequency signal transmitted by the transmitter, and transmitting the initially received radio frequency signal to the band-pass filter; the band-pass filter is used for filtering and suppressing the radio frequency signal to obtain a radio frequency signal after filtering and suppressing, and transmitting the radio frequency signal after filtering and suppressing to the detection and comparison unit; the detection and comparison unit is used for detecting and comparing the radio frequency signal after filtering and suppressing to obtain a radio frequency signal meeting a preset signal threshold, and transmitting the radio frequency signal meeting the preset signal threshold to the signal amplifier; and the signal amplifier is used for amplifying the radio frequency signal meeting the preset signal threshold to obtain a pre-processed radio frequency signal, and transmitting the pre-processed radio frequency signal to the power division module.

[0008] In the above scheme, the band-pass filter, the detection and comparison unit and the signal amplifier are introduced to provide multi-stage pre-processing for the radio frequency signal received by the receiving antenna, the band-pass filter effectively suppresses out-of-band interference and noise; the detection and comparison unit dynamically adjusts the pass state by monitoring the signal power in real time, ensures that the signal input to the power division module is always within the preset signal threshold range, and avoids nonlinear distortion or signal loss caused by excessively strong or weak signals; and the signal amplifier further improves the driving capability of the signal, and provides a stable and high-quality input source for subsequent diversity processing. Thus, the reliability of radio frequency signal transmission is ensured through the multi-stage pre-processing mechanism.

[0009] Further, the detection and comparison unit comprises a directional coupler, a detector, a comparator, a radio frequency switch and a signal attenuator; the first end of the directional coupler is electrically connected with the second end of the band-pass filter; the second end of the directional coupler is electrically connected with the first end of the detector; the third end of the directional coupler is electrically connected with the first end of the radio frequency switch; the second end of the detector is electrically connected with the first end of the comparator; the second end of the comparator is electrically connected with the second end of the radio frequency switch; the radio frequency switch is electrically connected with the first end of the signal amplifier; the radio frequency switch is connected in parallel with the signal attenuator; the detection and comparison unit is used for detecting and comparing the filtered and suppressed radio frequency signal, obtaining the radio frequency signal meeting the preset signal threshold and transmitting the radio frequency signal meeting the preset signal threshold to the signal amplifier; the directional coupler is used for coupling the filtered and suppressed radio frequency signal and transmitting the filtered and suppressed radio frequency signal to the detector; the detector is used for detecting the filtered and suppressed radio frequency signal, obtaining the corresponding signal power and outputting the voltage value corresponding to the signal power, and transmitting the voltage value to the comparator; the comparator is used for comparing the voltage value transmitted by the detector with the preset comparison voltage, generating a control signal according to the comparison result, and controlling the on-off relationship of the radio frequency switch; the radio frequency switch is used for receiving the control signal transmitted by the comparator, switching the corresponding on-off relationship to form different paths, transmitting the radio frequency signal meeting the preset signal threshold to the signal amplifier based on the different paths, and transmitting the radio frequency signal not meeting the preset signal threshold to the signal attenuator; and the signal attenuator is used for attenuating the power of the radio frequency signal not meeting the preset signal threshold until the radio frequency signal meeting the preset signal threshold is obtained, and transmitting the radio frequency signal meeting the preset signal threshold to the radio frequency switch.

[0010] In the above scheme, the directional coupler, the detector, the comparator, the radio frequency switch and the signal attenuator are cooperatively arranged, the detector detects the signal power in real time, the comparator generates a control signal, the radio frequency switch is automatically switched to a straight-through or attenuation path, and it is ensured that the signal input to the signal amplifier is always in the optimal working interval. Thus, through intelligent power management and path switching of the radio frequency signal, the amplifier saturation or distortion caused by an excessively strong input signal is effectively prevented, and the radio frequency signal cannot be effectively processed due to an excessively weak signal is also avoided, thereby ensuring the reliability of the radio frequency signal transmission.

[0011] Further, the frequency conversion module comprises a first-stage frequency conversion unit and a second-stage frequency conversion unit; the first end of the first-stage frequency conversion unit is electrically connected with the second end of the combining module; the second end of the first-stage frequency conversion unit is electrically connected with the first end of the second-stage frequency conversion unit; the second end of the second-stage frequency conversion unit is electrically connected with the signal modulation module; the first-stage frequency conversion unit is used for mixing the combined signal to obtain an intermediate frequency signal and transmitting the intermediate frequency signal to the second-stage frequency conversion unit; and the second-stage frequency conversion unit is used for down-converting the intermediate frequency signal to obtain a target modulation signal and transmitting the target modulation signal to the signal modulation module.

[0012] In the above scheme, the frequency conversion module adopts a two-stage mixing structure, and through the cooperative work of the first-stage frequency conversion unit and the second-stage frequency conversion unit, the combined signal is converted into an intermediate frequency signal and the intermediate frequency signal is down-converted into a low-frequency target modulation signal. Thus, the two-stage frequency conversion structure effectively suppresses the image frequency interference, realizes efficient conversion from the intermediate frequency to the target modulation signal, and guarantees the reliability of the radio frequency signal transmission.

[0013] Further, the first-stage frequency conversion unit comprises an electrically tunable filter, a first local oscillator signal acquisition subunit, and a first frequency mixer. The first end of the electrically tunable filter is electrically connected with the second end of the combining module. The second end of the electrically tunable filter is electrically connected with the first end of the first frequency mixer. The second end of the first frequency mixer is electrically connected with the first end of the first local oscillator signal acquisition subunit. The third end of the first frequency mixer is electrically connected with the first end of the second-stage frequency conversion unit. The second end of the first local oscillator signal acquisition subunit is electrically connected with the signal modulation module. The first-stage frequency conversion unit is used for mixing the combined signal to obtain an intermediate frequency signal and transmitting the intermediate frequency signal to the second-stage frequency conversion unit, comprising: the electrically tunable filter is used for adjusting the frequency characteristic of the combined signal to obtain a first frequency signal; the first local oscillator signal acquisition subunit is used for collecting a first analog signal emitted by the signal modulation module, performing two-stage filtering on the first analog signal to obtain a first filtered signal, and adjusting the frequency and phase of the first filtered signal to obtain a first local oscillator signal; and the first frequency mixer is used for down-converting the first frequency signal and the first local oscillator signal to obtain the intermediate frequency signal.

[0014] In the above scheme, the electrically tunable filter, the first local oscillator signal acquisition subunit, and the first frequency mixer are cooperatively arranged. The electrically tunable filter adjusts the frequency characteristic of the combined signal. The first local oscillator signal acquisition subunit provides a stable first local oscillator signal. Finally, the first frequency mixer down-converts the combined signal and the first local oscillator signal to obtain the intermediate frequency signal. Thus, the dependence on external local oscillator sources is reduced, the frequency adaptability and signal quality of the intermediate frequency signal are improved, and the reliability of the radio frequency signal transmission is guaranteed.

[0015] Further, the secondary frequency conversion unit comprises: a surface acoustic wave filter, a second mixer, a second local oscillator signal acquisition subunit, a filtering and amplifying subunit, and an analog-to-digital converter; the first end of the surface acoustic wave filter is electrically connected with the third end of the first mixer; the second end of the surface acoustic wave filter is electrically connected with the first end of the second mixer; the second end of the second mixer is electrically connected with the first end of the second local oscillator signal acquisition subunit; the third end of the second mixer is electrically connected with the first end of the filtering and amplifying subunit; the second end of the filtering and amplifying subunit is electrically connected with the first end of the analog-to-digital converter; the second end of the analog-to-digital converter is electrically connected with the signal modulation module; the second end of the second local oscillator signal acquisition subunit is electrically connected with the signal modulation module; the secondary frequency conversion unit is used for down-converting the intermediate frequency signal to obtain a target modulation signal, and transmitting the target modulation signal to the signal modulation module, comprising: the surface acoustic wave filter is used for adjusting the signal-to-noise ratio of the intermediate frequency signal to obtain a filtered intermediate frequency signal; the second local oscillator signal acquisition subunit is used for collecting a second analog signal emitted by the signal modulation module, performing one-stage filtering on the second analog signal to obtain a second filtered signal, and adjusting the frequency and phase of the second filtered signal to obtain a second local oscillator signal; the second mixer is used for down-converting the filtered intermediate frequency signal and the second local oscillator signal to obtain an initial target modulation signal; the filtering and amplifying subunit is used for amplifying and filtering the initial target modulation signal to obtain the target modulation signal; and the analog-to-digital converter is used for sampling the target modulation signal and transmitting the target modulation signal to the signal modulation module.

[0016] In the above scheme, the surface acoustic wave filter, the second mixer, the second local oscillator signal acquisition subunit, the filtering and amplifying subunit, and the analog-to-digital converter work cooperatively, the surface acoustic wave filter is used for adjusting the signal-to-noise ratio of the intermediate frequency signal to obtain a filtered intermediate frequency signal, the second local oscillator signal acquisition subunit is used for providing a stable second local oscillator signal, the second mixer is used for down-converting the second local oscillator signal and the filtered intermediate frequency signal, the filtering and amplifying subunit is used for optimizing the signal quality, the target modulation signal is obtained by the analog-to-digital converter, and the sampled target modulation signal is input to the signal modulation module. Thus, after the first frequency conversion, the secondary frequency conversion is performed, which can effectively suppress the image frequency interference, realize efficient conversion from the intermediate frequency to the target modulation signal, and guarantee the reliability of the radio frequency signal transmission.

[0017] The embodiment of the present application also provides a radio frequency signal receiving method, comprising: preprocessing an initial radio frequency signal received in advance by a radio frequency signal receiving processing module to obtain a preprocessed radio frequency signal; dividing the preprocessed radio frequency signal into a plurality of power division signals by a power division module, transmitting a plurality of power division signals of a preset proportion to a combining module, and transmitting the remaining power division signals to a combining module of an adjacent receiving link; combining the plurality of power division signals of the preset proportion and the remaining power division signals transmitted by the adjacent receiving link by the combining module to obtain a combined signal; performing frequency conversion processing on the combined signal by a frequency conversion module to obtain a target modulation signal; and demodulating the target modulation signal by a signal modulation module to complete radio frequency signal transmission.

[0018] The embodiment of the present application provides a radio frequency signal receiving method, which pre-processes a received radio frequency signal by a radio frequency signal receiving processing module, performs diversity on the pre-processed radio frequency signal by a power division module, combines the power division signals by a combining module to obtain a combined signal, and cooperates with the power division module and the combining module to ensure continuous signal transmission by other receiving links when a receiving link fails, and finally transmits the combined signal to a signal modulation module after frequency conversion to complete radio frequency signal transmission. Thus, the overall architecture of multiple receiving links is designed in combination with the local diversity design of the power division module and the combining module, so that the low intermediate frequency receiver is no longer paralyzed due to single point failure, and the reliability of radio frequency signal transmission is ensured.

[0019] Further, the radio frequency signal receiving processing module comprises a receiving antenna, a band pass filter, a detection comparison unit and a signal amplifier; the pre-processed radio frequency signal is obtained by preprocessing an initial radio frequency signal received in advance by the radio frequency signal receiving processing module, comprising: receiving an initial radio frequency signal transmitted by a transmitter by the receiving antenna; filtering and suppressing the radio frequency signal by the band pass filter to obtain a filtered and suppressed radio frequency signal; detecting and comparing the filtered and suppressed radio frequency signal by the detection comparison unit to obtain a radio frequency signal meeting a preset signal threshold; and amplifying the radio frequency signal meeting the preset signal threshold by the signal amplifier to obtain a pre-processed radio frequency signal.

[0020] In the above scheme, the band pass filter, the detection comparison unit and the signal amplifier are introduced to provide multi-stage preprocessing for the radio frequency signal received by the receiving antenna, the band pass filter effectively suppresses out-of-band interference and noise, the detection comparison unit monitors signal power in real time and dynamically adjusts the pass state, ensures that the signal input to the power division module is always within the preset signal threshold range, and avoids nonlinear distortion or signal loss caused by excessively strong or weak signals, and the signal amplifier further improves the driving capability of the signal, providing a stable and high-quality input source for subsequent diversity processing. Thus, the reliability of radio frequency signal transmission is ensured by the multi-stage preprocessing mechanism.

[0021] Further, the detection comparison unit comprises a directional coupler, a detector, a comparator, a radio frequency switch and a signal attenuator; the radio frequency signal satisfying the preset signal threshold is obtained by the detection comparison unit on the filtered and suppressed radio frequency signal, comprising: the filtered and suppressed radio frequency signal is coupled by the directional coupler; the filtered and suppressed radio frequency signal is detected by the detector to obtain the corresponding signal power and output the voltage value corresponding to the signal power; the voltage value is compared with the preset comparison voltage by the comparator, and the control signal is generated according to the comparison result; the control signal transmitted by the comparator is received by the radio frequency switch, the corresponding on-off relationship is switched to form different paths, and the radio frequency signal satisfying the preset signal threshold is transmitted to the signal amplifier based on different paths, and the radio frequency signal not satisfying the preset signal threshold is transmitted to the signal attenuator; the radio frequency signal not satisfying the preset signal threshold is power attenuated by the signal attenuator until the radio frequency signal satisfying the preset signal threshold is obtained, and the radio frequency signal satisfying the preset signal threshold is transmitted to the radio frequency switch.

[0022] In the above scheme, the directional coupler, the detector, the comparator, the radio frequency switch and the signal attenuator are cooperated, the signal power is detected by the detector in real time, the control signal is generated by the comparator, and the direct or attenuated path is automatically switched to ensure that the signal input to the signal amplifier is always in the best working interval. Therefore, through the intelligent power management and path switching of the radio frequency signal, the amplifier saturation or distortion caused by the input signal being too strong is effectively prevented, and the radio frequency signal cannot be effectively processed due to the signal being too weak is also avoided, and the reliability of the radio frequency signal transmission is ensured.

[0023] Further, the frequency conversion module comprises a primary frequency conversion unit and a secondary frequency conversion unit; the target modulation signal is obtained by the frequency conversion module on the combined signal, comprising: the combined signal is mixed by the primary frequency conversion unit to obtain an intermediate frequency signal; the intermediate frequency signal is down-converted by the secondary frequency conversion unit to obtain the target modulation signal.

[0024] In the above scheme, the frequency conversion module adopts a two-stage mixing structure, and the combined signal is converted into an intermediate frequency signal and a low-frequency target modulation signal through the cooperative work of the primary frequency conversion unit and the secondary frequency conversion unit. Therefore, the two-stage frequency conversion structure effectively suppresses the image frequency interference, realizes efficient conversion from the intermediate frequency to the target modulation signal, and ensures the reliability of the radio frequency signal transmission. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A module structure diagram of a low intermediate frequency receiver provided for an embodiment of the present application Figure 1 ;

[0026] Figure 2A module structure diagram of a low intermediate frequency receiver provided for an embodiment of the present application Figure 2 ;

[0027] Figure 3 A step flow diagram of a radio frequency signal receiving method provided for an embodiment of the present application DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0029] Embodiment 1

[0030] Referring to Figure 1 , Figure 1 A module structure diagram of a low intermediate frequency receiver provided for an embodiment of the present application Figure 1 . For example Figure 2As shown, it comprises: several completely same receiving links and signal modulation modules 5, any one receiving link comprises: a radio frequency signal receiving processing module 1, a power dividing module 2, a combining module 3 and a frequency conversion module 4; the first end of the radio frequency signal receiving processing module 1 is electrically connected with the first end of the power dividing module 2; the second end of the power dividing module 2 is electrically connected with the first end of the combining module 3, and the second end of the combining module 3 is electrically connected with the first end of the frequency conversion module 4; the third end of the power dividing module 2 is also electrically connected with the third end of the combining module 3 of the adjacent receiving link; the third end of the combining module 3 is also electrically connected with the third end of the power dividing module 2 of the adjacent receiving link; the second end of the frequency conversion module 4 is electrically connected with the signal modulation module 5; wherein the radio frequency signal receiving processing module 1 comprises: a receiving antenna, a band-pass filter, a detection comparison unit and a signal amplifier; the first end of the receiving antenna is electrically connected with the transmitter; the second end of the receiving antenna is electrically connected with the first end of the band-pass filter; the second end of the band-pass filter is electrically connected with the first end of the detection comparison unit; the second end of the detection comparison unit is electrically connected with the first end of the signal amplifier; the second end of the signal amplifier is electrically connected with the power dividing module 2; the detection comparison unit comprises: a directional coupler, a detector, a comparator, a radio frequency switch and a signal attenuator; the first end of the directional coupler is electrically connected with the second end of the band-pass filter; the second end of the directional coupler is electrically connected with the first end of the detector; the third end of the directional coupler is electrically connected with the first end of the radio frequency switch; the second end of the detector is electrically connected with the first end of the comparator; the second end of the comparator is electrically connected with the second end of the radio frequency switch; the radio frequency switch is electrically connected with the first end of the signal amplifier; the radio frequency switch is connected with the signal attenuator in parallel; the frequency conversion module 4 comprises: a first frequency conversion unit 41 and a second frequency conversion unit 42; the first end of the first frequency conversion unit 41 is electrically connected with the second end of the combining module 3; the second end of the first frequency conversion unit 41 is electrically connected with the first end of the second frequency conversion unit 42; the second end of the second frequency conversion unit 42 is electrically connected with the signal modulation module 5; the first frequency conversion unit 41 comprises: an electrically tunable filter, a first local oscillator signal acquisition sub-unit and a first mixer; the first end of the electrically tunable filter is electrically connected with the second end of the combining module 3; the second end of the electrically tunable filter is electrically connected with the first end of the first mixer; the second end of the first mixer is electrically connected with the first end of the first local oscillator signal acquisition sub-unit; the third end of the first mixer is electrically connected with the first end of the second frequency conversion unit 42; the second end of the first local oscillator signal acquisition sub-unit is electrically connected with the signal modulation module 5; the second frequency conversion unit 42 comprises: an acoustic surface filter, a second mixer, a second local oscillator signal acquisition sub-unit, a filter amplification sub-unit and an analog-to-digital converter; the first end of the acoustic surface filter is electrically connected with the third end of the first mixer; the second end of the acoustic surface filter is electrically connected with the first end of the second mixer; the second end of the second mixer is electrically connected with the first end of the second local oscillator signal acquisition sub-unit; the third end of the second mixer is electrically connected with the first end of the filter amplification sub-unit;The second end of the filter amplification sub-unit is electrically connected with the first end of the analog-to-digital converter; the second end of the analog-to-digital converter is electrically connected with the signal modulation module 5; the second end of the second local oscillator signal acquisition sub-unit is electrically connected with the signal modulation module 5;

[0031] In a specific embodiment, refer to Figure 2 , Figure 2 A module structure diagram of a low intermediate frequency receiver provided by an embodiment of the application Figure 2 ; as Figure 3 shown, based on the operation of a wireless microphone system based on 640-690MHz frequency, the wireless signal transmitted by the microphone (equivalent to the transmitter) is received by two antennas of the receiver, that is, in this embodiment, the receiving link is set to two paths, recorded as A link and B link, and the radio frequency signal is input from the antenna A port or the antenna B port, wherein the antenna A port is recorded as ANT_A, and the antenna B port is recorded as ANT_B; since the two receiving links are set to be completely consistent, the radio frequency signal input from ANT_A is taken as an example for explanation, after the radio frequency signal is received by ANT_A, it is transmitted to the radio frequency signal receiving and processing module 1, and is received by the band-pass filter of the radio frequency signal receiving and processing module 1, in this embodiment, the band-pass filter adopts an LC band-pass filter; after the radio frequency signal is processed by the band-pass filter, it is transmitted to the detection comparison unit, in the detection comparison unit, the coupling port of the directional coupler is connected with the input pin of the detector, and the detector outputs a corresponding voltage value according to the radio frequency signal power output coupled by the directional coupler, for example, when the directional coupler couples high power, the detector outputs high voltage; according to the output voltage value, after comparison with the comparison voltage of the comparator, a control signal is generated, which controls the on-off of the radio frequency switch, in this embodiment, the radio frequency switch is set to two SPDT radio frequency switches, and the SPDT radio frequency switch is a single-pole double-throw radio frequency switch; by switching the on-off relationship of the radio frequency switch, the paths that can be obtained include: a straight-through path and an attenuation path, the straight-through path is to directly transmit the radio frequency signal from the directional coupler to the signal amplifier, and the attenuation path is to transmit the radio frequency signal to the signal amplifier after passing through the signal attenuator, thus completing the radio frequency signal preprocessing.

[0032] In the above scheme, the introduction of the band-pass filter, the detection comparison unit and the signal amplifier provides multi-stage preprocessing for the radio frequency signal received by the receiving antenna, the band-pass filter effectively suppresses out-of-band interference and noise; the detection comparison unit dynamically adjusts the pass state by monitoring the signal power in real time, ensures that the signal input to the power division module 2 is always within the preset signal threshold range, and avoids nonlinear distortion or signal loss caused by excessively strong or weak signals; the signal amplifier further improves the driving capability of the signal, providing a stable and high-quality input source for subsequent diversity processing. Thus, the reliability of radio frequency signal transmission is ensured through the multi-stage preprocessing mechanism. Among them, the cooperative action of the directional coupler, the detector, the comparator, the radio frequency switch and the signal attenuator in the detection comparison unit, the detector detects the signal power in real time, and generates a control signal through the comparator, automatically switches to the straight-through or attenuation path, ensures that the signal input to the signal amplifier is always in the best working interval. Thus, through intelligent power management and path switching of the radio frequency signal, the saturation or distortion of the amplifier caused by excessively strong input signals is effectively prevented, and the situation that the radio frequency signal cannot be effectively processed due to excessively weak signals is also avoided, ensuring the reliability of radio frequency signal transmission.

[0033] After completing the signal preprocessing, the preprocessed radio frequency signal is transmitted to the power division module 2, and the power division module 2 is set to a one-to-two mode, dividing the radio frequency signal into two signals, one of which is transmitted along the A link to the combiner, and the other is transmitted to the combiner of the B link; then the combiner of the A link combines the radio frequency signal transmitted by the B link and the radio frequency signal transmitted by the A link into one combiner signal. In this embodiment, the power divider and the combiner use the same device, which is a device that can divide the energy of one input signal into two or more output equal or unequal energy, or can combine multiple signal energies into one output. Through the cooperative action of the power divider and the combiner, even if only one of the A link or the B link is used, two signals can also be obtained through power division and transmitted to the signal modulation module 5 for demodulation.

[0034] After the two-way signal is combined to obtain the combined signal, the combined signal enters the first frequency conversion unit 41. First, the combined signal is transmitted to the first mixer after passing through the electrically tunable filter. At this time, the first local oscillator signal is obtained from the signal modulation module 5 by the first local oscillator signal acquisition subunit. Specifically, the first local oscillator signal acquisition subunit is provided with a DAC digital-to-analog converter, two-stage LTCC filters, a phase-locked loop, and a power divider. The LTCC filter is a low-temperature co-fired ceramic filter. It is worth mentioning that the first local oscillator signal is divided into A-link and B-link by the power divider in the first local oscillator signal acquisition subunit, so that two phase-locked loops are not needed, saving design cost. After obtaining the first local oscillator signal, the first mixer mixes the first local oscillator signal and the signal output from the electrically tunable filter to generate an intermediate frequency signal, and transmits the intermediate frequency signal to the second frequency conversion unit 42.

[0035] In the above scheme, the frequency conversion module 4 adopts a two-stage frequency conversion structure. Through the cooperative work of the first frequency conversion unit 41 and the second frequency conversion unit 42, the combined signal is converted into an intermediate frequency signal and the intermediate frequency signal is down-converted to a low-frequency target modulation signal. Thus, the adoption of the two-stage frequency conversion structure effectively suppresses the mirror frequency interference, realizes efficient conversion from the intermediate frequency to the target modulation signal, and guarantees the reliability of the radio frequency signal transmission. The first frequency conversion unit 41 is provided with an electrically tunable filter, a first local oscillator signal acquisition subunit, and a first mixer that work cooperatively. The electrically tunable filter adjusts the frequency characteristics of the combined signal. The first local oscillator signal acquisition subunit provides a stable first local oscillator signal. Finally, the first mixer down-converts the combined signal and the first local oscillator signal to obtain the intermediate frequency signal. Thus, the dependence on external local oscillator sources is reduced, the frequency adaptability and signal quality of the intermediate frequency signal are improved, and the reliability of the radio frequency signal transmission is guaranteed.

[0036] After the first frequency conversion is completed, the second frequency conversion unit 42 is also provided in the embodiment to shift the radio frequency signal to a low frequency band. Specifically, the intermediate frequency signal is first transmitted to a surface acoustic wave filter for processing, and then transmitted to a second mixer. At the same time, the second local oscillator signal acquisition subunit obtains the second local oscillator signal from the signal modulation module 5. The second local oscillator signal acquisition subunit is provided with a DAC digital-to-analog converter, a one-stage LTCC filter, a phase-locked loop, and a power divider. Similarly, the power divider can divide the second local oscillator signal into A-link and B-link. Then, the second mixer down-converts the second local oscillator signal and the intermediate frequency signal processed by the surface acoustic wave filter to obtain an initial target modulation signal. The signal is then amplified and filtered by the filtering and amplifying subunit to obtain the target modulation signal. In the embodiment, the filtering and amplifying subunit includes an LNA amplifier and a low-pass filter. Finally, the target modulation signal is collected by the ADC analog-to-digital converter and transmitted to the signal modulation module 5 for demodulation. Thus, the reception of the radio frequency signal is completed. In the embodiment, the signal modulation module 5 is implemented by an FPGA.

[0037] In the above scheme, the acoustic surface filter, the second frequency mixer, the second local oscillator signal acquisition subunit, the filter amplification subunit and the analog-to-digital converter work together to adjust the signal-to-noise ratio of the intermediate frequency signal through the acoustic surface filter to obtain a filtered intermediate frequency signal, the second local oscillator signal acquisition subunit provides a stable second local oscillator signal, and then the second frequency mixer down-converts the second local oscillator signal and the filtered intermediate frequency signal, and then the signal quality is optimized through the filter amplification subunit to obtain a target modulation signal which is sampled by the analog-to-digital converter to input the sampled target modulation signal to the signal modulation module 5. Thus, after the first frequency conversion and the second frequency conversion, the image frequency interference can be effectively suppressed, the efficient conversion from the intermediate frequency to the target modulation signal is realized, and the reliability of the radio frequency signal transmission is ensured.

[0038] Based on the above example of the low intermediate frequency receiver corresponding to the connection relationship of the wireless microphone system operating based on the 640-690MHz frequency, the working principle of each device is further explained as follows: the radio frequency signal receiving and processing module 1 is used for preprocessing the initial radio frequency signal received to obtain a preprocessed radio frequency signal, and transmitting the preprocessed radio frequency signal to the power division module 2; including: a receiving antenna for receiving the initial radio frequency signal transmitted by the transmitter, and transmitting the initial radio frequency signal to a band pass filter; the band pass filter is used for filtering and suppressing the radio frequency signal to obtain a radio frequency signal after filtering and suppression, and transmitting the radio frequency signal after filtering and suppression to a detection and comparison unit; the detection and comparison unit is used for detecting and comparing the radio frequency signal after filtering and suppression to obtain a radio frequency signal satisfying a preset signal threshold, and transmitting the radio frequency signal satisfying the preset signal threshold to a signal amplifier, including: the detection and comparison unit is used for detecting and comparing the radio frequency signal after filtering and suppression to obtain a radio frequency signal satisfying a preset signal threshold and transmitting the radio frequency signal satisfying the preset signal threshold to a signal amplifier, including: a directional coupler for coupling the radio frequency signal after filtering and suppression, and transmitting the radio frequency signal after filtering and suppression to a detector; the detector is used for detecting the radio frequency signal after filtering and suppression to obtain a corresponding signal power and outputting a voltage value corresponding to the signal power, and transmitting the voltage value to a comparator; the comparator is used for comparing the voltage value transmitted by the detector with a preset comparison voltage, and generating a control signal according to the comparison result to control the on-off relationship of the radio frequency switch; the radio frequency switch is used for receiving the control signal transmitted by the comparator, switching the corresponding on-off relationship to form different paths, transmitting the radio frequency signal satisfying the preset signal threshold to the signal amplifier based on the different paths, and transmitting the radio frequency signal not satisfying the preset signal threshold to a signal attenuator; the signal attenuator is used for attenuating the power of the radio frequency signal not satisfying the preset signal threshold until the radio frequency signal satisfying the preset signal threshold is obtained, and transmitting the radio frequency signal satisfying the preset signal threshold to the radio frequency switch. The signal amplifier is used for amplifying the radio frequency signal satisfying the preset signal threshold to obtain a preprocessed radio frequency signal, and transmitting the preprocessed radio frequency signal to the power division module 2.The power division module 2 is used for dividing the preprocessed radio frequency signal into a plurality of power division signals, transmitting a plurality of power division signals of a preset proportion to the combining module 3, and transmitting the remaining plurality of power division signals to the combining module 3 of the adjacent receiving chain; the combining module 3 is used for combining the plurality of power division signals of the preset proportion and the remaining plurality of power division signals transmitted by the adjacent receiving chain to obtain a combined signal, and transmitting the combined signal to the frequency conversion module 4; the frequency conversion module 4 is used for frequency conversion processing on the combined signal to obtain a target modulation signal, and transmitting the target modulation signal to the signal modulation module 5; the signal modulation module 5 is used for demodulating the target modulation signal to complete the radio frequency signal transmission, wherein the frequency conversion module 4 includes a first frequency conversion unit 41 and a second frequency conversion unit 42; the first frequency conversion unit 41 is used for mixing the combined signal to obtain an intermediate frequency signal, and transmitting the intermediate frequency signal to the second frequency conversion unit 42, including: an electrically adjustable filter for adjusting the frequency characteristic of the combined signal to obtain a first frequency signal; a first local oscillator signal acquisition subunit for collecting a first analog signal emitted by the signal modulation module 5, performing two-stage filtering on the first analog signal to obtain a first filtered signal, and adjusting the frequency and phase of the first filtered signal to obtain a first local oscillator signal; a first frequency mixer for down-converting the first frequency signal and the first local oscillator signal to obtain the intermediate frequency signal. The second frequency conversion unit 42 is used for down-converting the intermediate frequency signal to obtain the target modulation signal, and transmitting the target modulation signal to the signal modulation module 5, including: an acoustic surface filter for adjusting the signal-to-noise ratio of the intermediate frequency signal to obtain a filtered intermediate frequency signal; a second local oscillator signal acquisition subunit for collecting a second analog signal emitted by the signal modulation module 5, performing one-stage filtering on the second analog signal to obtain a second filtered signal, and adjusting the frequency and phase of the second filtered signal to obtain a second local oscillator signal; a second frequency mixer for down-converting the filtered intermediate frequency signal and the second local oscillator signal to obtain an initial target modulation signal; a filtering and amplifying subunit for amplifying and filtering the initial target modulation signal to obtain the target modulation signal; an analog-to-digital converter for sampling the target modulation signal and transmitting it to the signal modulation module 5.

[0039] In a specific embodiment, the wireless signal transmitted by the microphone (equivalent to the transmitter) is received by two antennas of the receiver, i.e., in this embodiment, the receiving link is set to two paths, denoted as A link and B link, and the radio frequency signal is input from the antenna A port or the antenna B port, wherein the antenna A port is denoted as ANT_A, and the antenna B port is denoted as ANT_B. Since the two receiving links are set to be completely consistent, the radio frequency signal input from the ANT_A is taken as an example for explanation. After the radio frequency signal is received by the ANT_A, it is transmitted to the radio frequency signal receiving and processing module 1, and is received by the band-pass filter of the radio frequency signal receiving and processing module 1. In this embodiment, the band-pass filter is an LC band-pass filter, the passband frequency of the LC band-pass filter is set to 640-690 MHz, a three-order filter is used, and the out-of-band suppression is about 20 dB. After the radio frequency signal is processed by the band-pass filter, it is transmitted to the detection and comparison unit. In the detection and comparison unit, the directional coupler is a device widely used in microwave and millimeter wave systems, mainly used for signal isolation, separation and mixing. It can realize functions such as power monitoring, source output power stabilization, signal source isolation, transmission and reflection sweep test, etc. The coupling port of the directional coupler is connected with the input pin of the detector. The detector outputs a corresponding voltage value according to the radio frequency signal power coupled by the directional coupler. By comparing the voltages of the two input ends, different output voltages are generated at the output end. The function here is mainly applied to prevent the gain of the entire link from entering the nonlinear region due to the oversaturation of the radio frequency signal, thereby generating distortion. For example, when the antenna input signal is too large, the power coupled by the coupler to the detector also increases. After the high voltage output by the detector is compared with the comparison voltage of the comparator, the two SPDT radio frequency switches are controlled. According to the voltage value output, the comparison voltage of the comparator is compared, and a control signal is generated to control the on-off of the two SPDT radio frequency switches. In this embodiment, the radio frequency switch is set to two SPDT radio frequency switches. By switching the on-off relationship of the radio frequency switch, the paths that can be obtained include: a straight path and an attenuation path. The straight path is to directly transmit the radio frequency signal from the directional coupler to the signal amplifier, and the attenuation path is to transmit the radio frequency signal to the signal amplifier after passing through the signal attenuator. Specifically, when the signal is normal, the radio frequency signal normally passes through the two SPDT radio frequency switches, i.e., the straight path. When the signal increases to exceed the preset signal threshold, the comparator controls the SPDT radio frequency switch to switch to the attenuator path, i.e., the attenuation path, and the radio frequency signal passes through the attenuator to attenuate the power, thereby ensuring the normality of the subsequent link. Finally, it comes to the signal amplifier. In this embodiment, an LNA is used. The LNA is a low-noise amplifier mainly used for amplifying radio frequency signals. After the radio frequency signal passes through the LNA, it enters the power divider, and the radio frequency signal preprocessing is completed.

[0040] After the radio frequency signal enters the power divider, the power divider divides the input signal energy into two or more output equal or unequal energy, and the equal or unequal energy division of the signal energy is characterized as transmitting a plurality of power division signals with a preset ratio to the combining module 3 and transmitting the remaining plurality of power division signals to the combining module 3 of the adjacent receiving link; specifically, the radio frequency signal is divided into two output, one side of the signal of the A link continues to walk the A link, and the other side is connected to the second level power divider of the B link; similarly, the power divider of the B link also divides one into two, one side enters the second level power divider of the A link, and the other side enters the second level power divider of the B link; the second level power divider is a combiner in this embodiment, that is, the multi-path signal energy is combined into one output, the A and B respective branch signals are combined again, and then output to the electrically adjustable filter; thus, a true diversity function can be realized, and even only one of the A link antenna or the B link antenna can be finally given to the FPGA for demodulation through the two-way signal.

[0041] After the combination of the signals, the combined signal enters the first frequency conversion unit 41. The combined signal is first transmitted to the first mixer after passing through the electrically tunable filter. In this embodiment, the function of the electrically tunable filter is to adjust its frequency characteristics according to the requirements, that is, a kind of band-pass filter that can change the passband frequency. The electrically tunable filter is used here because its passband is relatively narrow and the out-of-band suppression is high. It can be stacked with the first LC band-pass filter to meet the higher image frequency suppression. After the electrically tunable filter processes the radio frequency signal, it is output to the first mixer. Then the first local oscillator signal is obtained from the signal modulation module 5. Specifically, the first local oscillator signal acquisition subunit is provided with a DAC digital-to-analog converter, two-stage LTCC filter, phase-locked loop and power divider. It is worth mentioning that by setting the power divider in the first local oscillator signal acquisition subunit, the first local oscillator signal is power divided into A link and B link, so that two phase-locked loops are not needed, saving design cost. In an example of this embodiment, the first local oscillator signal is provided by the FPGA. The FPGA outputs 8-bit serial data and SPI control high-speed DAC digital-to-analog converter. A high-speed analog signal is output through the high-speed DAC digital-to-analog converter. Then the two-stage LTCC filter is used to filter the high-speed analog signal. The first reason for using the LTCC filter is that the out-of-band suppression of the high-speed analog signal is very high, and the transition band is relatively steep. The high-frequency DAC digital-to-analog converter output is prone to generate a lot of high-frequency components and quantization noise, which avoids the generation of image frequency after entering the mixer. The high-speed analog signal filtered by the two-stage LTCC filter enters the input pin of the PLL phase-locked loop. The phase-locked loop outputs a stable high-frequency signal. Since there are two A and B links, a power divider is applied to the output of the phase-locked loop for splitting, so that two phase-locked loops are not needed, saving cost. Finally, the output of the power divider serves as the first local oscillator signal, which is provided to the mixer for frequency mixing. After obtaining the first local oscillator signal, the first mixer mixes the first local oscillator signal and the signal output from the electrically tunable filter to generate an intermediate frequency signal. Since the system frequency in this embodiment is 640-690MHz, the frequency of the first local oscillator signal is selected as 883-933MHz for down-conversion, and the intermediate frequency signal frequency is 243MHz. The intermediate frequency signal is transmitted to the second frequency conversion unit 42.

[0042] After the first-stage frequency conversion is completed, the second-stage frequency conversion unit 42 is further arranged in the embodiment to shift the radio frequency signal to a low frequency band. Specifically, the intermediate frequency signal is first transmitted to a surface acoustic wave filter for processing, and then transmitted to a second mixer. The intermediate frequency signal passes through the surface acoustic wave filter, which has a narrow bandwidth and good out-of-band suppression, and is specially applied to the output of the mixer. The second local oscillator signal acquisition subunit obtains the second local oscillator signal from the signal modulation module 5. The second local oscillator signal acquisition subunit is provided with a DAC digital-to-analog converter, a first-stage LTCC filter, a phase-locked loop, and a power divider. Similarly, the power divider can divide the second local oscillator signal into A-link and B-link. Then, the second mixer down-converts the second local oscillator signal and the intermediate frequency signal processed by the surface acoustic wave filter to obtain an initial target modulation signal. The FPGA controls the DAC digital-to-analog converter of the second local oscillator signal acquisition subunit to output the second local oscillator signal to the phase-locked loop. The frequency of the second local oscillator signal is 245 MHz. At this time, the frequency of the initial target modulation signal is reduced to 2 MHz. Then, the initial target modulation signal is output to the ADC analog-to-digital converter for sampling through the low-noise amplifier and the low-pass filter. The ADC analog-to-digital converter outputs the target modulation signal to the FPGA for demodulation. Thus, a complete true diversity low intermediate frequency receiver link is completed. In the embodiment, the filtering and amplifying subunit includes an LNA amplifier and a low-pass filter. Thus, the reception of the radio frequency signal is completed.

[0043] The embodiment of the present application provides a low intermediate frequency receiver. A plurality of receiving links are arranged, and a radio frequency signal receiving processing module 1, a power dividing module 2, a combining module 3 and a frequency conversion module 4 are arranged in each receiving link. The radio frequency signal receiving processing module 1 pre-processes the received radio frequency signal. The power dividing module 2 divides the pre-processed radio frequency signal. The combining module 3 combines the divided power dividing signals to obtain a combined signal. When a fault occurs in a receiving link, the continuous transmission of the signal can still be ensured through the cooperation of other receiving links. Finally, the combined signal is sent to the signal modulation module 5 for demodulation after frequency conversion by the frequency conversion module 4, so as to complete the transmission of the radio frequency signal. Thus, the overall architecture of the multiple receiving links is designed, and the local true diversity design of the power dividing module 2 and the combining module 3 are combined, so that the low intermediate frequency receiver is no longer paralyzed due to a single point fault, and the reliability of the radio frequency signal transmission is ensured.

[0044] Embodiment 2

[0045] Reference Figure 3 , Figure 3 A step flowchart of a radio frequency signal receiving method provided by the embodiment of the present application is shown in FIG. 1. ​ The embodiment of the present application provides a radio frequency signal receiving method, which comprises steps 101 to 105, and each step is specifically as follows.

[0046] Step 101, pre-process the initial radio frequency signal received by the radio frequency signal receiving processing module 1 to obtain a pre-processed radio frequency signal;

[0047] Step 102, divide the pre-processed radio frequency signal into several power division signals by the power division module 2, and transmit a preset proportion of the several power division signals to the combining module 3, and transmit the remaining several power division signals to the combining module 3 of the adjacent receiving link;

[0048] Step 103, combine the preset proportion of the several power division signals and the remaining several power division signals transmitted by the adjacent receiving link by the combining module 3 to obtain a combined signal;

[0049] Step 104, frequency conversion processing of the combined signal by the frequency conversion module 4 to obtain a target modulation signal;

[0050] Step 105, demodulate the target modulation signal by the signal modulation module 5 to complete the radio frequency signal transmission.

[0051] A specific embodiment, for example, based on the wireless microphone system operating at 640-690 MHz frequency, the wireless signal transmitted by the microphone (equivalent to the transmitter) is received by two antennas of the receiver, that is, in this embodiment, the receiving link is set to two-way, recorded as A link and B link, respectively, the radio frequency signal is input from the antenna A port or B port, wherein the antenna A port is recorded as ANT_A, and the antenna B port is recorded as ANT_B; Since the two-way receiving link is set to be completely consistent, taking the radio frequency signal input from ANT_A as an example for explanation, the radio frequency signal is received by ANT_A and transmitted to the radio frequency signal receiving and processing module 1, which is received by the band-pass filter of the radio frequency signal receiving and processing module 1, in this embodiment, the band-pass filter adopts LC band-pass filter; The radio frequency signal is transmitted to the detection comparison unit after being processed by the band-pass filter, in which the coupling port of the directional coupler is connected with the input pin of the detector, and the detector outputs a corresponding voltage value according to the radio frequency signal power output coupled by the directional coupler, for example, when the directional coupler couples high power, the detector outputs high voltage; According to the output voltage value, after comparing with the comparison voltage of the comparator, a control signal is generated to control the on-off of the radio frequency switch, in this embodiment, the radio frequency switch is set to two SPDT; The on-off relationship of the radio frequency switch is switched, and the paths that can be obtained include: straight path and attenuation path, the straight path is directly transmitting the radio frequency signal from the directional coupler to the signal amplifier, and the attenuation path is transmitting the radio frequency signal to the signal amplifier after passing through the signal attenuator, thus completing the radio frequency signal preprocessing. After completing the signal preprocessing, the preprocessed radio frequency signal is transmitted to the power division module 2, which is set to one-to-two mode, dividing the radio frequency signal into two-way signals, one-way signal is transmitted to the combiner along the A link, and the other way signal is transmitted to the combiner of the B link; Then the combiner of the A link combines the radio frequency signal transmitted by the B link and the radio frequency signal transmitted by the A link into one-way combined signal, in this embodiment, the power divider and the combiner adopt the same device, which is a device capable of dividing one-way input signal energy into two-way or multiple-way output equal or unequal energy, or vice versa. Through the synergistic effect of the power divider and the combiner, even if only one of the A link or the B link is used, two-way signals can also be obtained through power division and transmitted to the signal modulation module 5 for demodulation.After the completion of the combination of the signals, the combined signal enters the first frequency conversion unit 41. First, the combined signal is transmitted to the first mixer after passing through the electrically adjustable filter. At this time, the first local oscillator signal is obtained from the signal modulation module 5 by the first local oscillator signal acquisition subunit. Specifically, the first local oscillator signal acquisition subunit is provided with a DAC digital-to-analog converter, two-stage LTCC filters, a phase-locked loop, and a power divider. It is worth mentioning that the first local oscillator signal is divided into A-link and B-link by the power divider in the first local oscillator signal acquisition subunit, so that two phase-locked loops are not needed, thereby saving design costs. After obtaining the first local oscillator signal, the first mixer mixes the first local oscillator signal with the signal output from the electrically adjustable filter to generate an intermediate frequency signal, and transmits the intermediate frequency signal to the second frequency conversion unit 42. After the completion of the first frequency conversion, the second frequency conversion unit 42 is also provided in the embodiment to shift the radio frequency signal to a low frequency band. Specifically, the intermediate frequency signal is first transmitted to the acoustic surface filter for processing, and then transmitted to the second mixer. At the same time, the second local oscillator signal is obtained from the signal modulation module 5 by the second local oscillator signal acquisition subunit. The second local oscillator signal acquisition subunit is provided with a DAC digital-to-analog converter, a one-stage LTCC filter, a phase-locked loop, and a power divider. Similarly, the power divider can divide the second local oscillator signal into A-link and B-link. Then, the second mixer down-converts the second local oscillator signal and the intermediate frequency signal processed by the acoustic surface filter to obtain an initial target modulation signal, and then performs signal amplification and filtering on the initial target modulation signal by the filtering and amplifying subunit to obtain a target modulation signal. In the embodiment, the filtering and amplifying subunit includes an LNA amplifier and a low-pass filter. Finally, the target modulation signal is collected by the ADC analog-to-digital converter and transmitted to the signal modulation module 5 for demodulation. Thus, the reception of the radio frequency signal is completed. In the embodiment, the signal modulation module 5 is implemented by an FPGA.

[0052] The embodiment of the present application proposes a radio frequency signal receiving method. The received radio frequency signal is preprocessed by the radio frequency signal receiving processing module 1. The preprocessed radio frequency signal is divided by the power division module 2, and then the divided signals are combined by the combination module 3 to obtain a combined signal. Through the cooperative work of the power division module 2 and the combination module 3, when a certain receiving link fails, the continuous transmission of the signal can still be ensured by other receiving links. Finally, the combined signal is frequency-converted by the frequency conversion module 4 and sent to the signal modulation module 5 for demodulation to complete the transmission of the radio frequency signal. Thus, by designing the overall architecture of the multiple receiving links and combining the local diversity design of the power division module 2 and the combination module 3, the low intermediate frequency receiver is no longer paralyzed due to a single point failure, thereby ensuring the reliability of the radio frequency signal transmission.

[0053] Further, the radio frequency signal receiving and processing module 1 comprises a receiving antenna, a band-pass filter, a detection and comparison unit, and a signal amplifier; the pre-received initial radio frequency signal is pre-processed by the radio frequency signal receiving and processing module 1 to obtain a pre-processed radio frequency signal, including: receiving the initial radio frequency signal transmitted by the transmitter through the receiving antenna; filtering and suppressing the radio frequency signal through the band-pass filter to obtain a filtered and suppressed radio frequency signal; detecting and comparing the filtered and suppressed radio frequency signal through the detection and comparison unit to obtain a radio frequency signal satisfying a preset signal threshold; and amplifying the radio frequency signal satisfying the preset signal threshold through the signal amplifier to obtain a pre-processed radio frequency signal.

[0054] In the above scheme, the band-pass filter, the detection and comparison unit, and the signal amplifier are introduced to provide multi-stage preprocessing for the radio frequency signal received by the receiving antenna, effectively suppress the out-of-band interference and noise through the band-pass filter; the signal power is monitored in real time and the pass state is dynamically adjusted through the detection and comparison unit, ensuring that the signal input into the power division module 2 is always within the preset signal threshold range, avoiding nonlinear distortion or signal loss caused by excessively strong or weak signals; the signal amplifier further improves the driving capability of the signal, providing a stable and high-quality input source for subsequent diversity processing. Thus, the reliability of radio frequency signal transmission is ensured through the multi-stage preprocessing mechanism.

[0055] Further, the detection and comparison unit comprises a directional coupler, a detector, a comparator, a radio frequency switch, and a signal attenuator; the radio frequency signal after filtering and suppression is detected and compared by the detection and comparison unit to obtain a radio frequency signal satisfying a preset signal threshold, including: coupling the radio frequency signal after filtering and suppression through the directional coupler; detecting the radio frequency signal after filtering and suppression through the detector to obtain the corresponding signal power and output the voltage value corresponding to the signal power; comparing the voltage value with the preset comparison voltage through the comparator, and generating a control signal according to the comparison result; receiving the control signal transmitted by the comparator through the radio frequency switch, switching the corresponding on-off relationship to form different paths, transmitting the radio frequency signal satisfying the preset signal threshold to the signal amplifier based on different paths, and transmitting the radio frequency signal not satisfying the preset signal threshold to the signal attenuator; attenuating the power of the radio frequency signal not satisfying the preset signal threshold through the signal attenuator until the radio frequency signal satisfying the preset signal threshold is obtained, and transmitting the radio frequency signal satisfying the preset signal threshold to the radio frequency switch.

[0056] In the above scheme, the cooperative action of the directional coupler, the detector, the comparator, the radio frequency switch and the signal attenuator is arranged, the detector detects the signal power in real time, and the control signal is generated through the comparator, and the straight-through or attenuation path is automatically switched to, so that the signal input to the signal amplifier is always in the optimal working interval. Therefore, through intelligent power management and path switching of the radio frequency signal, the amplifier saturation or distortion caused by the input signal being too strong is effectively prevented, and at the same time, the radio frequency signal cannot be effectively processed due to the signal being too weak is also avoided, and the reliability of the radio frequency signal transmission is ensured.

[0057] Further, the frequency conversion module 4 comprises: a first frequency conversion unit 41 and a second frequency conversion unit 42; the target modulation signal is obtained by frequency conversion processing of the combined signal through the frequency conversion module 4, comprising: mixing the combined signal through the first frequency conversion unit 41 to obtain an intermediate frequency signal; the intermediate frequency signal is down-converted through the second frequency conversion unit 42 to obtain the target modulation signal.

[0058] In the above scheme, the frequency conversion module 4 adopts a two-stage mixing structure, and through the cooperative work of the first frequency conversion unit 41 and the second frequency conversion unit 42, the combined signal is converted into an intermediate frequency signal and the intermediate frequency signal is down-converted to a low-frequency target modulation signal. Therefore, the two-stage frequency conversion structure effectively suppresses the image frequency interference, realizes efficient conversion from the intermediate frequency to the target modulation signal, and ensures the reliability of the radio frequency signal transmission.

[0059] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be considered as the protection scope of the present application.

[0060] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0061] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

Claims

1. A low intermediate frequency receiver, characterized by The low intermediate frequency receiver comprises a plurality of identical receiving links and a signal modulation module, any one of the receiving links comprises: a radio frequency signal receiving processing module, a power division module, a combination module and a frequency conversion module; a first end of the radio frequency signal receiving processing module is electrically connected with a first end of the power division module; a second end of the power division module is electrically connected with a first end of the combination module, a second end of the combination module is electrically connected with a first end of the frequency conversion module; a third end of the power division module is further electrically connected with a third end of a combination module of an adjacent receiving link; a third end of the combination module is further electrically connected with a third end of a power division module of the adjacent receiving link; a second end of the frequency conversion module is electrically connected with the signal modulation module; the radio frequency signal receiving processing module is used for pre-processing a pre-received initial radio frequency signal to obtain a pre-processed radio frequency signal, and transmitting the pre-processed radio frequency signal to the power division module; the power division module is used for dividing the pre-processed radio frequency signal into a plurality of power division signals, transmitting a preset proportion of the plurality of power division signals to the combination module, and transmitting the remaining plurality of power division signals to the combination module of the adjacent receiving link; the combination module is used for combining the preset proportion of the plurality of power division signals and the remaining plurality of power division signals transmitted by the adjacent receiving link to obtain a combination signal, and transmitting the combination signal to the frequency conversion module; the frequency conversion module is used for frequency conversion processing the combination signal to obtain a target modulation signal, and transmitting the target modulation signal to the signal modulation module; the signal modulation module is used for demodulating the target modulation signal to complete radio frequency signal transmission.

2. A low intermediate frequency receiver as claimed in claim 1, characterized in that the radio frequency signal receiving processing module comprises a receiving antenna, a band pass filter, a detection comparison unit and a signal amplifier; a first end of the receiving antenna is electrically connected with a transmitter; a second end of the receiving antenna is electrically connected with a first end of the band pass filter; a second end of the band pass filter is electrically connected with a first end of the detection comparison unit; a second end of the detection comparison unit is electrically connected with a first end of the signal amplifier; a second end of the signal amplifier is electrically connected with the power division module; the radio frequency signal receiving processing module is used for pre-processing a pre-received initial radio frequency signal to obtain a pre-processed radio frequency signal, and transmitting the pre-processed radio frequency signal to the power division module, comprising: the receiving antenna is used for receiving an initial radio frequency signal transmitted by the transmitter, and transmitting the initial radio frequency signal to the band pass filter; the band pass filter is used for filtering and suppressing the radio frequency signal to obtain a radio frequency signal after filtering and suppression, and transmitting the radio frequency signal after filtering and suppression to the detection comparison unit; the detection comparison unit is used for detecting and comparing the radio frequency signal after filtering and suppression to obtain a radio frequency signal satisfying a preset signal threshold, and transmitting the radio frequency signal satisfying the preset signal threshold to the signal amplifier; the signal amplifier is used for amplifying the radio frequency signal satisfying the preset signal threshold to obtain a pre-processed radio frequency signal, and transmitting the pre-processed radio frequency signal to the power division module.

3. A low intermediate frequency receiver as claimed in claim 2, characterized in that The detection comparison unit comprises a directional coupler, a detector, a comparator, a radio frequency switch and a signal attenuator. The first end of the directional coupler is electrically connected with the second end of the band-pass filter; the second end of the directional coupler is electrically connected with the first end of the detector; the third end of the directional coupler is electrically connected with the first end of the radio frequency switch; the second end of the detector is electrically connected with the first end of the comparator; the second end of the comparator is electrically connected with the second end of the radio frequency switch; the radio frequency switch is electrically connected with the first end of the signal amplifier; and the radio frequency switch is connected in parallel with the signal attenuator. The detection comparison unit is used for detecting and comparing the filtered and suppressed radio frequency signal, obtaining a radio frequency signal satisfying a preset signal threshold and transmitting the radio frequency signal satisfying the preset signal threshold to the signal amplifier, and comprises: The directional coupler is used for coupling the filtered and suppressed radio frequency signal and transmitting the filtered and suppressed radio frequency signal to the detector. The detector is used for detecting the filtered and suppressed radio frequency signal, obtaining a corresponding signal power and outputting a voltage value corresponding to the signal power, and transmitting the voltage value to the comparator. The comparator is used for comparing the voltage value transmitted by the detector with a preset comparison voltage, generating a control signal according to a comparison result, and controlling the on-off relationship of the radio frequency switch. The radio frequency switch is used for receiving the control signal transmitted by the comparator, switching a corresponding on-off relationship to form different paths, transmitting a radio frequency signal satisfying the preset signal threshold to the signal amplifier based on the different paths, and transmitting a radio frequency signal not satisfying the preset signal threshold to the signal attenuator. The signal attenuator is used for attenuating the power of the radio frequency signal not satisfying the preset signal threshold until a radio frequency signal satisfying the preset signal threshold is obtained, and transmitting the radio frequency signal satisfying the preset signal threshold to the radio frequency switch.

4. A low intermediate frequency receiver as claimed in claim 1, characterized in that The frequency conversion module comprises a primary frequency conversion unit and a secondary frequency conversion unit. The first end of the primary frequency conversion unit is electrically connected with the second end of the combining module; the second end of the primary frequency conversion unit is electrically connected with the first end of the secondary frequency conversion unit; and the second end of the secondary frequency conversion unit is electrically connected with the signal modulation module. The primary frequency conversion unit is used for mixing the combined signal to obtain an intermediate frequency signal and transmitting the intermediate frequency signal to the secondary frequency conversion unit. The secondary frequency conversion unit is used for down-converting the intermediate frequency signal to obtain a target modulation signal and transmitting the target modulation signal to the signal modulation module.

5. A low intermediate frequency receiver as claimed in claim 4, characterized in that The primary frequency conversion unit comprises an electrically tunable filter, a first local oscillator signal acquisition subunit and a first frequency mixer. The first end of the electrically tunable filter is electrically connected with the second end of the combining module; the second end of the electrically tunable filter is electrically connected with the first end of the first frequency mixer; the second end of the first frequency mixer is electrically connected with the first end of the first local oscillator signal acquisition subunit; the third end of the first frequency mixer is electrically connected with the first end of the second frequency conversion unit; the second end of the first local oscillator signal acquisition subunit is electrically connected with the signal modulation module; The first frequency conversion unit is used for mixing the combined signal to obtain an intermediate frequency signal and transmitting the intermediate frequency signal to the second frequency conversion unit, and comprises: The electrically tunable filter is used for adjusting the frequency characteristic of the combined signal to obtain a first frequency signal; The first local oscillator signal acquisition subunit is used for collecting a first analog signal emitted by the signal modulation module, performing second filtering on the first analog signal to obtain a first filtered signal, and adjusting the frequency and phase of the first filtered signal to obtain a first local oscillator signal; The first frequency mixer is used for down-converting the first frequency signal and the first local oscillator signal to obtain an intermediate frequency signal.

6. A low intermediate frequency receiver as claimed in claim 5, characterized in that The second frequency conversion unit comprises: a surface acoustic wave filter, a second frequency mixer, a second local oscillator signal acquisition subunit, a filtering and amplifying subunit, and an analog-to-digital converter; The first end of the surface acoustic wave filter is electrically connected with the third end of the first frequency mixer; the second end of the surface acoustic wave filter is electrically connected with the first end of the second frequency mixer; the second end of the second frequency mixer is electrically connected with the first end of the second local oscillator signal acquisition subunit; the third end of the second frequency mixer is electrically connected with the first end of the filtering and amplifying subunit; the second end of the filtering and amplifying subunit is electrically connected with the first end of the analog-to-digital converter; the second end of the analog-to-digital converter is electrically connected with the signal modulation module; the second end of the second local oscillator signal acquisition subunit is electrically connected with the signal modulation module; The second frequency conversion unit is used for down-converting the intermediate frequency signal to obtain a target modulation signal and transmitting the target modulation signal to the signal modulation module, and comprises: The surface acoustic wave filter is used for adjusting the signal-to-noise ratio of the intermediate frequency signal to obtain a filtered intermediate frequency signal; The second local oscillator signal acquisition subunit is used for collecting a second analog signal emitted by the signal modulation module, performing first filtering on the second analog signal to obtain a second filtered signal, and adjusting the frequency and phase of the second filtered signal to obtain a second local oscillator signal; The second frequency mixer is used for down-converting the filtered intermediate frequency signal and the second local oscillator signal to obtain an initial target modulation signal; The filtering and amplifying subunit is used for amplifying and filtering the initial target modulation signal to obtain a target modulation signal; The analog-to-digital converter is used for sampling the target modulation signal and transmitting the target modulation signal to the signal modulation module.

7. A method of receiving a radio frequency signal, characterized by, The method is executed by the low intermediate frequency receiver according to any one of claims 1 to 6, and comprises: The initial radio frequency signal is preprocessed by a radio frequency signal receiving processing module to obtain a preprocessed radio frequency signal; The initial radio frequency signal is preprocessed by a radio frequency signal receiving processing module to obtain a preprocessed radio frequency signal; The power division module divides the preprocessed radio frequency signal into several power division signals, transmits several power division signals of a preset ratio to the combining module, and transmits the remaining several power division signals to the combining module of an adjacent receiving link; The combining module combines several power division signals of a preset ratio and the remaining several power division signals transmitted by the adjacent receiving link to obtain a combined signal; The frequency conversion module performs frequency conversion processing on the combined signal to obtain a target modulation signal; The signal modulation module demodulates the target modulation signal to complete radio frequency signal transmission.

8. A method of receiving a radio frequency signal as claimed in claim 7, characterized in that, The radio frequency signal receiving processing module includes a receiving antenna, a bandpass filter, a detection comparison unit, and a signal amplifier; the radio frequency signal receiving processing module preprocesses the initially received initial radio frequency signal to obtain a preprocessed radio frequency signal, including: The receiving antenna receives the initial radio frequency signal transmitted by the transmitter; The bandpass filter filters and suppresses the radio frequency signal to obtain a filtered and suppressed radio frequency signal; The detection comparison unit detects and compares the filtered and suppressed radio frequency signal to obtain a radio frequency signal that meets a preset signal threshold; The signal amplifier amplifies the radio frequency signal that meets the preset signal threshold to obtain a preprocessed radio frequency signal.

9. A method of receiving a radio frequency signal as claimed in claim 8, characterized in that, The detection comparison unit includes a directional coupler, a detector, a comparator, a radio frequency switch, and a signal attenuator; the detection comparison unit detects and compares the filtered and suppressed radio frequency signal to obtain a radio frequency signal that meets a preset signal threshold, including: The directional coupler couples the filtered and suppressed radio frequency signal; The detector detects the filtered and suppressed radio frequency signal to obtain the corresponding signal power and outputs the voltage value corresponding to the signal power; The comparator compares the voltage value with a preset comparison voltage and generates a control signal according to the comparison result; The radio frequency switch receives the control signal transmitted by the comparator, switches the corresponding on-off relationship to form different paths, transmits the radio frequency signal that meets the preset signal threshold to the signal amplifier based on different paths, and transmits the radio frequency signal that does not meet the preset signal threshold to the signal attenuator; The signal attenuator attenuates the power of the radio frequency signal that does not meet the preset signal threshold until the radio frequency signal that meets the preset signal threshold is obtained, and transmits the radio frequency signal that meets the preset signal threshold to the radio frequency switch.

10. A method of receiving a radio frequency signal as claimed in claim 7, characterized in that, The frequency conversion module includes a primary frequency conversion unit and a secondary frequency conversion unit; the frequency conversion module performs frequency conversion processing on the combined signal to obtain a target modulation signal, including: The primary frequency conversion unit mixes the combined signal to obtain an intermediate frequency signal; The secondary frequency conversion unit down-converts the intermediate frequency signal to obtain a target modulation signal.

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