High-dynamic full-wave receiving radio frequency channel

Abstract

The invention relates to the technical field of radio-frequency channels, in particular to a high-dynamic full-wave receiving radio-frequency channel which is composed of a radio-frequency signal processing circuit, a frequency mixing circuit and an intermediate-frequency signal processing circuit, after radio-frequency filtering is carried out on a changed radio-frequency signal, the radio-frequency signal is changed into a fixed intermediate-frequency signal through frequency mixing, and the fixed intermediate-frequency signal is used for narrow-band intermediate-frequency filtering and amplification. And outputting the signal of which the amplitude and the signal-to-noise ratio meet the requirements to a baseband unit for sampling and processing. The high-dynamic full-wave receiving radio frequency channel provided by the invention has the advantage of effectively improving the working range of the radio frequency receiving frequency, can perform amplification, filtering, frequency mixing, gain control and the like on wireless signals in the frequency range of 10KHz-30MHz, and meets the requirements of wide input dynamic range input signals. According to the radio frequency receiving channel, stable, high-signal-to-noise-ratio and low-distortion intermediate frequency signals are output to a baseband part for sampling all the time, and the problems that a common radio frequency receiving channel at present is single in radio frequency receiving frequency working range and cannot cover the frequency range of 10 KHz to 30 MHz are solved.

Description

Technical Field

[0001] The invention relates to the technical field of radio frequency channels, in particular to a high-dynamic full-wave receiving radio frequency channel. Background Art

[0002] Channelization is a common technology for RF broadband receivers. In the frequency domain channelization process, the received signal is divided into narrowband sub-channels, avoiding interference between overlapping signals in the time domain and having good separation capabilities for high-density signal streams.

[0003] The full-wave receiving RF channel is mainly composed of RF, mixing, and intermediate frequency circuits. After filtering the 10KHz~30MHz RF signal, it is converted into a fixed intermediate frequency signal through mixing, which is convenient for narrowband filtering and amplification, and the output amplitude and signal-to-noise ratio meet the requirements of the signal to the baseband unit for sampling and processing. At present, in common receiving RF channels, the RF receiving frequency working range is relatively single and cannot cover the frequency range of 10KHz~30MHz. For this reason, we propose a high-dynamic full-wave receiving RF channel to solve this problem. Summary of the invention

[0004] The purpose of the present invention is to provide a high-dynamic full-wave receiving radio frequency channel, which has the advantage of effectively improving the working range of the radio frequency receiving frequency, and solves the problem that the current common receiving radio frequency channels have a relatively single working range of the radio frequency receiving frequency and cannot cover the frequency range of 10KHz to 30MHz.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a high-dynamic full-wave receiving radio frequency channel, which is composed of a radio frequency signal processing circuit, a mixing circuit and an intermediate frequency signal processing circuit. After the changing radio frequency signal is subjected to radio frequency filtering, it is converted into a fixed intermediate frequency signal through mixing, which is used for narrow-band intermediate frequency filtering and amplification, and the signal with amplitude and signal-to-noise ratio that meet the requirements is output to the baseband unit for sampling and processing;

[0006] RF signal processing circuit, used for front-end protection, amplification, filtering, RFAGC control, etc. of the signal received by the antenna, conditioning the RF signal, improving the signal-to-noise ratio and suppressing out-of-band signals;

[0007] The mixer circuit mixes the RF signal in the wide frequency range and outputs a fixed intermediate frequency signal, which is used to process the signal and improve the signal quality;

[0008] The intermediate frequency signal processing circuit processes the intermediate frequency signal through multi-stage amplification and multiple bandwidth filtering circuits to improve the signal out-of-band suppression capability.

[0009] Preferably, the radio frequency signal processing circuit is composed of a radio frequency front-end protection, a low-pass filter, a single-pole four-throw radio frequency switch, a low-noise amplifier circuit and a segmented filtering circuit.

[0010] Preferably, the functional characteristics of the radio frequency signal processing circuit are as follows:

[0011] RF front-end protection mainly provides lightning protection and large signal limiting protection for RF front-end circuits to prevent large signals from damaging receiving front-end devices.

[0012] Low-pass filter, which filters the frequency signals above 30MHz to reduce the linear influence of high-frequency out-of-band signals on the subsequent circuits;

[0013] SP4T RF switch, switching between two low noise amplifier circuits, attenuation circuit and through circuit;

[0014] The low noise amplifier circuit is divided into two frequency bands, namely low noise amplifier 1: 10KHz~1MHz, low noise amplifier 2: 1MHz~30MHz;

[0015] The segmented filtering circuit is divided into 12 groups of filters, which filter signals in different frequency bands separately to improve the ability to suppress out-of-band interference.

[0016] Preferably, the frequency mixing circuit is composed of a mixer, a bandpass filter, a local oscillator amplifier and a frequency synthesizer circuit.

[0017] Preferably, the functional characteristics of the mixing circuit are as follows:

[0018] Mixer: A passive mixer with high dynamic range and high linearity is selected;

[0019] Bandpass filter, which filters the frequency synthesizer output frequency and removes out-of-band spurious signals and local oscillator harmonic signals;

[0020] The local oscillator amplifier uses a gain amplifier with a strong output capability to increase the amplitude of the local oscillator signal to meet the high local oscillator amplitude requirement of the passive mixer;

[0021] The frequency synthesizer circuit realizes frequency generation within the frequency range of 70.01MHz to 100MHz through a local phase-locked loop circuit.

[0022] Preferably, the intermediate frequency signal processing circuit is composed of an intermediate frequency input bandpass filter, a digitally controlled attenuator, an intermediate frequency amplifier, an intermediate frequency output bandpass filter, a coupler and a detector.

[0023] Preferably, the functional characteristics of the intermediate frequency signal processing circuit are as follows:

[0024] The intermediate frequency input bandpass filter uses a two-stage narrowband crystal bandpass filter to perform narrowband filtering on the 70M intermediate frequency signal to improve the signal out-of-band spurious suppression performance;

[0025] Digitally controlled attenuator: The intermediate frequency part adopts a two-stage digitally controlled attenuator with a maximum digitally controlled gain control range of 63dB. Combined with the 30dB gain control range at the RF end, the maximum gain control range can be 93dB, achieving high dynamic working capability of reception;

[0026] Intermediate frequency amplifier: The intermediate frequency part adopts a two-stage high-gain intermediate frequency amplifier circuit to provide high gain for reception;

[0027] The IF output bandpass filter is mainly used to suppress the harmonic signals and clutter signals generated by other IF circuits and improve the signal-to-noise ratio output to the AD sampling circuit;

[0028] The coupler couples the intermediate frequency output signal and performs field strength signal detection;

[0029] The detector uses a detection chip to detect the RSSI field strength of the coupled intermediate frequency signal and outputs a DC voltage signal that is proportional to the RF signal.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The high-dynamic full-wave receiving radio frequency channel proposed in the present invention has the advantage of being able to effectively improve the working range of the radio frequency receiving frequency. It consists of three parts: a radio frequency signal processing circuit, a mixing circuit and an intermediate frequency signal processing circuit. After the changing radio frequency signal is subjected to radio frequency filtering, it is converted into a fixed intermediate frequency signal through mixing, which is used for narrow-band intermediate frequency filtering and amplification. The output signal with amplitude and signal-to-noise ratio meeting the requirements is sent to the baseband unit for sampling and processing. The wireless signal in the frequency range of 10KHz to 30MHz can be amplified, filtered, mixed, gain controlled, etc. When the input signal meets the wide input dynamic range, a stable, high signal-to-noise ratio, and low-distortion intermediate frequency signal is always output to the baseband part for sampling, which solves the problem that the current common receiving radio frequency channel has a relatively single working range of the radio frequency receiving frequency and cannot cover the frequency range of 10KHz to 30MHz. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a block diagram of the full-wave receiving radio frequency channel system of the present invention;

[0033] Figure 2 This is a block diagram of the radio frequency processing circuit of the present invention;

[0034] Figure 3 The block diagram of the mixing circuit of the present invention is as follows;

[0035] Figure 4 It is a block diagram of the intermediate frequency processing circuit of the present invention;

[0036] Figure 5 A receiving gain distribution diagram of a receiving channel of the present invention;

[0037] Figure 6 This is a receiving automatic gain control diagram of the receiving channel of the present invention.

[0038] In the figure: 1. RF signal processing circuit; 2. Mixing circuit; 3. Intermediate frequency signal processing circuit; 4. RF front-end protection; 5. Low-pass filter; 6. Single-pole four-throw RF switch; 7. Low-noise amplifier circuit; 8. Segmented filtering circuit; 9. Mixer; 10. Band-pass filter; 11. Local oscillator amplifier; 12. Frequency synthesizer circuit; 13. Intermediate frequency input band-pass filter; 14. Digitally controlled attenuator; 15. Intermediate frequency amplifier; 16. Intermediate frequency output band-pass filter; 17. Coupler; 18. Detector. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Embodiment 1:

[0041] A high-dynamic full-wave receiving RF channel consists of three parts: an RF signal processing circuit, a mixing circuit and an intermediate frequency signal processing circuit. After the changing RF signal is subjected to RF filtering, it is converted into a fixed intermediate frequency signal through mixing, which is used for narrow-band intermediate frequency filtering and amplification, and the output signal with amplitude and signal-to-noise ratio that meet the requirements is sent to the baseband unit for sampling and processing.

[0042] (1) RF signal processing circuit, which is used to perform front-end protection, amplification, filtering, RFAGC control, etc. on the signal received by the antenna, condition the RF signal, improve the signal-to-noise ratio and suppress out-of-band signals;

[0043] In this embodiment, the radio frequency signal processing circuit is composed of a radio frequency front-end protection, a low-pass filter, a single-pole four-throw radio frequency switch, a low-noise amplifier circuit and a segmented filtering circuit.

[0044] In this embodiment, the functional characteristics of the radio frequency signal processing circuit are as follows:

[0045] RF front-end protection mainly provides lightning protection and large signal limiting protection for RF front-end circuits to prevent large signals from damaging receiving front-end devices.

[0046] Low-pass filter filters the frequency signals above 30MHz to reduce the linear influence of high-frequency out-of-band signals on the subsequent circuits. At the same time, the filter has a lower input insertion loss, which reduces the deterioration of the receiving signal-to-noise ratio.

[0047] The single-pole four-throw RF switch switches between two types of low-noise amplifier circuits, attenuation circuits, and direct-through circuits. Controlled by the RFAGC signal, it switches between different operating frequency amplifications and different gain states. When a small signal is input in the low-frequency band, it switches to the low-noise amplifier channel 1; when a small signal is input in the high-frequency band, it switches to the low-noise amplifier channel 2; when a large input signal does not need to be amplified, it switches to the direct-through channel; when the input signal is very large, it switches to the attenuation channel, which can achieve a gain control range of 30dB in the RF band;

[0048] The low-noise amplifier circuit is divided into two frequency bands, namely low-noise amplifier 1: 10KHz~1MHz, and low-noise amplifier 2: 1MHz~30MHz, which are respectively realized by low-noise operational amplifier circuits and radio frequency amplifier circuits that can work in the corresponding frequency bands;

[0049] The segmented filtering circuit is divided into 12 groups of filters, which filter signals in different frequency bands respectively to improve the ability to suppress out-of-band interference. It is mainly used to provide lightning protection and large signal limiting protection for the RF front-end circuit to prevent large signals from damaging the receiving front-end devices.

[0050] (2) Mixing circuit: After mixing the RF signal in the wide frequency band, it outputs a fixed intermediate frequency signal, which is used to process the signal and improve the signal quality.

[0051] In this embodiment, the frequency mixing circuit is composed of a mixer, a bandpass filter, a local oscillator amplifier and a frequency synthesizer circuit.

[0052] In this embodiment, the functional characteristics of the mixer circuit are as follows:

[0053] Mixer: A passive mixer with high dynamic range and high linearity is selected;

[0054] Bandpass filter, which filters the frequency synthesizer output frequency and removes out-of-band spurious signals and local oscillator harmonic signals;

[0055] The local oscillator amplifier uses a gain amplifier with a strong output capability to increase the amplitude of the local oscillator signal to meet the high local oscillator amplitude requirement of the passive mixer;

[0056] The frequency synthesizer circuit realizes frequency generation within the frequency range of 70.01MHz to 100MHz through a local phase-locked loop circuit.

[0057] (3) Intermediate frequency signal processing circuit, which processes the intermediate frequency signal through multi-stage amplification and multiple bandwidth filtering circuits to improve the signal out-of-band suppression capability.

[0058] In this embodiment, the intermediate frequency signal processing circuit is composed of an intermediate frequency input bandpass filter, a digitally controlled attenuator, an intermediate frequency amplifier, an intermediate frequency output bandpass filter, a coupler and a detector.

[0059] In this embodiment, the functional characteristics of the intermediate frequency signal processing circuit are as follows:

[0060] The intermediate frequency input bandpass filter uses a two-stage narrowband crystal bandpass filter to perform narrowband filtering on the 70M intermediate frequency signal to improve the signal out-of-band spurious suppression performance;

[0061] Digitally controlled attenuator: The intermediate frequency part adopts a two-stage digitally controlled attenuator with a maximum digitally controlled gain control range of 63dB. Combined with the 30dB gain control range at the RF end, the maximum gain control range can be 93dB, achieving high dynamic working capability of reception;

[0062] Intermediate frequency amplifier: The intermediate frequency part adopts a two-stage high-gain intermediate frequency amplifier circuit to provide high gain for reception;

[0063] The IF output bandpass filter is mainly used to suppress the harmonic signals and clutter signals generated by other IF circuits and improve the signal-to-noise ratio output to the AD sampling circuit;

[0064] The coupler couples the intermediate frequency output signal and performs field strength signal detection as a reference for signal strength;

[0065] The detector uses a detection chip to detect the RSSI field strength of the coupled intermediate frequency signal and outputs a DC voltage signal that is proportional to the RF signal.

[0066] In this embodiment, the total gain of the receiving channel mainly depends on the interface level requirements of the baseband unit and the minimum input receiving level of the whole machine. According to the system requirements, when the input sensitivity signal is -113dBm (0.5uV), it can still output an intermediate frequency signal with an amplitude of not less than -65dBm to the baseband A / D sampling, and the total gain needs to reach 48dB. The entire receiver is mainly divided into two parts, the RF and the intermediate frequency, which are gain-amplified separately. If the gain of the RF part is too low, it will affect the channel noise coefficient, and if it is too high, it will reduce the channel dynamic range. Therefore, a 14dB static gain is set. The intermediate frequency part contributes most of the gain to the channel, with a 41dB static gain. After deducting the loss of frequency conversion -7dB, the total static gain is 48dB, which can meet the requirements.

[0067] In this embodiment, the automatic gain control circuit is a key part of receiving high dynamics. By controlling the RF switch and the digitally controlled attenuator of the intermediate frequency part, the amplitude of the output intermediate frequency signal can be guaranteed to be approximately constant when different amplitude RF signals are input. The receiving channel is designed with 30dB and 63dB gain dynamic adjustment circuits in the RF band and the intermediate frequency band respectively. The entire receiving channel is designed with a gain control range of not less than 93dB, which can meet the processing capability of linear output when the +10dBm signal is input. The control of the attenuator follows the principle of compression first and attenuation first. The intermediate frequency band is controlled first, and the RF band is controlled later, to avoid the influence of the RF band attenuation on the receiver signal-to-noise ratio when the signal is small.

[0068] In this embodiment, the segmented filtering frequency bands of the segmented filtering circuit are shown in the following table:

[0069] Serial number Frequency band 1 10kHz~22kHz 2 22kHz~46kHz 3 46kHz~100kHz 4 100kHz~215kHz 5 215kHz~464kHz 6 464kHz~1.0MHz 7 1.0MHz~1.8MHz 8 1.8MHz~3.1MHz 9 3.1MHz~5.5MHz 10 5.5MHz~9.6MHz 11 9.6MHz~17MHz 12 17MHz~30MHz

[0070] In summary, the high-dynamic full-wave receiving RF channel proposed in the present invention is composed of three parts: an RF signal processing circuit, a mixing circuit and an intermediate frequency signal processing circuit. After the changing RF signal is subjected to RF filtering, it is converted into a fixed intermediate frequency signal through mixing, which is used for narrow-band intermediate frequency filtering and amplification. The output amplitude and signal-to-noise ratio meet the requirements of the signal to be sampled and processed by the baseband unit. The wireless signal in the frequency range of 10KHz to 30MHz can be amplified, filtered, mixed, gain controlled, etc. When the input signal meets the wide input dynamic range, a stable, high signal-to-noise ratio, and low-distortion intermediate frequency signal is always output to the baseband part for sampling.

[0071] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high dynamic full wave receiving RF channel, Features: It consists of three parts: RF signal processing circuit, mixing circuit and intermediate frequency signal processing circuit. After the changing RF signal is subjected to RF filtering, it is converted into a fixed intermediate frequency signal through mixing, which is used for narrowband intermediate frequency filtering and amplification. The output signal with amplitude and signal-to-noise ratio that meet the requirements is sent to the baseband unit for sampling and processing. RF signal processing circuit, used for front-end protection, amplification, filtering, RFAGC control, etc. of the signal received by the antenna, conditioning the RF signal, improving the signal-to-noise ratio and suppressing out-of-band signals; The mixer circuit mixes the RF signal in the wide frequency range and outputs a fixed intermediate frequency signal, which is used to process the signal and improve the signal quality; The intermediate frequency signal processing circuit processes the intermediate frequency signal through multi-stage amplification and multiple bandwidth filtering circuits to improve the signal out-of-band suppression capability.

2. A high dynamic full wave receiving radio frequency channel according to claim 1, Features: The radio frequency signal processing circuit is composed of a radio frequency front-end protection, a low-pass filter, a single-pole four-throw radio frequency switch, a low-noise amplifier circuit and a segmented filtering circuit.

3. A high dynamic full wave receiving radio frequency channel according to claim 2, Features: The functional characteristics of the radio frequency signal processing circuit are as follows: RF front-end protection mainly provides lightning protection and large signal limiting protection for RF front-end circuits to prevent large signals from damaging receiving front-end devices. Low-pass filter, which filters the frequency signals above 30MHz to reduce the linear influence of high-frequency out-of-band signals on the subsequent circuits; SP4T RF switch, switching between two low noise amplifier circuits, attenuation circuit and through circuit; The low noise amplifier circuit is divided into two frequency bands, namely low noise amplifier 1: 10KHz~1MHz, low noise amplifier 2: 1MHz~30MHz; The segmented filtering circuit is divided into 12 groups of filters, which filter signals in different frequency bands separately to improve the ability to suppress out-of-band interference.

4. A high dynamic full wave receiving radio frequency channel according to claim 1, Features: The frequency mixing circuit is composed of a mixer, a bandpass filter, a local oscillator amplifier and a frequency synthesizer circuit.

5. A high dynamic full wave receiving radio frequency channel according to claim 4, Features: The functional characteristics of the mixing circuit are as follows: Mixer: A passive mixer with high dynamic range and high linearity is selected; Bandpass filter, which filters the frequency synthesizer output frequency and removes out-of-band spurious signals and local oscillator harmonic signals; The local oscillator amplifier uses a gain amplifier with a strong output capability to increase the amplitude of the local oscillator signal to meet the high local oscillator amplitude requirement of the passive mixer; The frequency synthesizer circuit realizes frequency generation within the frequency range of 70.01MHz to 100MHz through a local phase-locked loop circuit.

6. A high dynamic full wave receiving radio frequency channel according to claim 1, Features: The intermediate frequency signal processing circuit is composed of an intermediate frequency input bandpass filter, a digitally controlled attenuator, an intermediate frequency amplifier, an intermediate frequency output bandpass filter, a coupler and a detector.

7. A high dynamic full wave receiving radio frequency channel according to claim 6, Features: The functional characteristics of the intermediate frequency signal processing circuit are as follows: The intermediate frequency input bandpass filter uses a two-stage narrowband crystal bandpass filter to perform narrowband filtering on the 70M intermediate frequency signal to improve the signal out-of-band spurious suppression performance; Digitally controlled attenuator: The intermediate frequency part adopts a two-stage digitally controlled attenuator with a maximum digitally controlled gain control range of 63dB. Combined with the 30dB gain control range at the RF end, the maximum gain control range can be 93dB, achieving high dynamic working capability of reception; Intermediate frequency amplifier: The intermediate frequency part adopts a two-stage high-gain intermediate frequency amplifier circuit to provide high gain for reception; The IF output bandpass filter is mainly used to suppress the harmonic signals and clutter signals generated by other IF circuits and improve the signal-to-noise ratio output to the AD sampling circuit; The coupler couples the intermediate frequency output signal and performs field strength signal detection; The detector uses a detection chip to detect the RSSI field strength of the coupled intermediate frequency signal and outputs a DC voltage signal that is proportional to the RF signal.

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