Broadband transmit-receive channel circuit

Abstract

The utility model belongs to the technical field of communication, and discloses a wide-frequency-band transceiving channel circuit, which comprises a receiving circuit, a transmitting circuit and a receiving circuit, the receiving circuit comprises a low-pass filter, a numerical control attenuator, an amplitude limiter, an LNA amplifier, a radio frequency switch, a segmented low-pass filter, a radio frequency switch, a low-pass filter, a frequency mixer, a band-pass filter, a radio frequency amplifier, a band-pass filter, a frequency mixer, a low-pass filter, a numerical control attenuator, a radio frequency amplifier, a numerical control attenuator, a radio frequency amplifier and a radio frequency switch which are connected in sequence; a filter, a radio frequency switch, a radio frequency amplifier and a low-pass filter are selected according to different bandwidths; the system also comprises a transmitting circuit. The transmitting circuit comprises a numerical control attenuator, a radio frequency amplifier, a tuned filter and a radio frequency switch which are connected in sequence. According to the utility model, a superheterodyne receiver architecture and a twice frequency mixing design are adopted, and the antenna also has the advantages of wide frequency band, high gain, high dynamic range and multiple bandwidth modes.

Description

Technical Field

[0001] The utility model relates to the technical field of communications, in particular to a wide-band transceiver channel circuit. Background Art

[0002] With the development and maturity of wireless communication technology, there are more and more application scenarios for wide frequency bands such as VHF / UHF plus L-band, and there are more applications for channels that can meet the use of wide frequency bands. The existing designs and applications are mainly in VHF / UHF transceiver channels and L-band transceiver channels. By integrating the broadband of VHF / UHF plus L-band, applications in various different scenarios can be realized. Especially in the scenario of multi-channel resources, the combination of different functions can be realized through the allocation of channel resources.

[0003] Currently, the predominant architecture of transceivers is still a superheterodyne architecture for both receiving and transmitting channels. (This is based on a heterodyne process, in which an input signal and a frequency-shifted local oscillator signal are mixed in a nonlinear device to generate an intermediate frequency. This intermediate frequency is the frequency offset between the local oscillator signal and the input signal. This nonlinear device is a mixer. In a superheterodyne architecture, the frequency conversion operation may occur more than once, so single-frequency superheterodyne and double-frequency superheterodyne are often seen.) However, the inventors have discovered in actual applications that the existing transceiver channel circuit design is not simple enough. Therefore, they have proposed a wide-band transceiver channel circuit. Utility Model Content

[0004] In order to overcome the above-mentioned defects of the prior art, the inventors have conducted in-depth research and completed the present utility model after paying a lot of creative work.

[0005] Specifically, the technical problem to be solved by the present invention is to provide a wide-band transceiver channel circuit to solve the technical problem that the existing transceiver channel circuit design is not simple enough.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A wide-band transceiver channel circuit comprises: a receiving circuit;

[0008] The receiving circuit includes a low-pass filter, a digitally controlled attenuator, a limiter, an LNA amplifier, a radio frequency switch, a segmented low-pass filter, a radio frequency switch, a low-pass filter, a mixer, a band-pass filter, a radio frequency amplifier, a band-pass filter, a mixer, a low-pass filter, a digitally controlled attenuator, a radio frequency amplifier, a digitally controlled attenuator, a radio frequency amplifier, a radio frequency switch, filters for selecting different bandwidths, a radio frequency switch, a radio frequency amplifier, and a low-pass filter, which are connected in sequence. The receiving circuit adopts a superheterodyne architecture, detects the received signal strength in real time through a signal detection circuit, controls a multi-stage AGC circuit to adjust the signal amplitude, and has a high dynamic range while meeting high sensitivity, so as to realize the reception of various different signals.

[0009] Also included: a transmitting circuit;

[0010] The transmitting circuit includes a digitally controlled attenuator, a radio frequency amplifier, a tuned filter, and a radio frequency switch connected in sequence. The transmitting circuit adopts radio frequency direct transmission. Through the amplification and filtering circuits, it can not only ensure the amplitude of the output signal, but also reduce out-of-band interference signals.

[0011] As an improved technical solution, the digitally controlled attenuator realizes a gain control range of 1-3 levels, where each level is 30dB and the step is 1dB. The gain characteristic design gain control range is achieved by a 3-level digitally controlled attenuator, where each level is 30dB and the step is 1dB. The attenuator switching time is very short, which can meet the switching requirements of all application scenarios.

[0012] As an improved technical solution, the digitally controlled attenuators together form a three-stage AGC control circuit in the receiving circuit channel, wherein the digitally controlled attenuators connected in sequence together form a three-stage AGC control circuit in the receiving channel. The first digitally controlled attenuator in the receiving circuit is called a radio frequency AGC circuit, the second digitally controlled attenuator in the receiving circuit is called an intermediate frequency AGC1 (automatic gain control 1) circuit, and the third digitally controlled attenuator in the receiving circuit is called an intermediate frequency AGC2 (automatic gain control 2) circuit. The coordinated work of the three AGCs can achieve a maximum attenuation of 90dB, ensuring that the receiving channel can operate normally under both small and large signal conditions.

[0013] As an improved technical solution, the frequency of the radio frequency signal input to the radio frequency port of the receiving circuit and the input and output of the radio frequency port of the transmitting circuit is 30MHz to 2500MHz. When the radio frequency signal passes through the limiter and the three-stage digitally controlled attenuator, the high dynamic range of the radio frequency signal can be guaranteed;

[0014] When the RF signal passes through low-pass, band-pass, low-pass and different bandwidth selection filters, it can effectively suppress image frequency interference 80dBc and intermediate frequency interference 80dBc, ensuring the high anti-interference performance of the circuit.

[0015] After adopting the above technical solution, the beneficial effects of the utility model are:

[0016] 1. The utility model adopts modular circuit design. The receiving circuit and the transmitting circuit are laid out and designed separately. The functional circuits of each part are separated by a metal cavity, which can effectively shield the interference between signals to ensure high reliability. The receiving circuit adopts a superheterodyne receiver architecture and a two-time mixing design, and the transmitting circuit adopts RF direct transmission. The overall design has the advantages of wide frequency band, high gain, high dynamic range, and compatibility with multiple bandwidth modes.

[0017] 2. The receiving circuit of the present invention adopts a superheterodyne architecture, which detects the received signal strength in real time through the post-stage signal detection circuit and controls the multi-stage AGC circuit to adjust the signal amplitude. It has a high dynamic range while meeting the sensitivity requirements to achieve reception of different signal strengths.

[0018] 3. In the present invention, the transmitting circuit adopts radio frequency direct transmission, and through the amplification and filtering circuits, it can not only ensure the amplitude of the output signal, but also reduce the out-of-band interference signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work. Among them:

[0020] Figure 1 The figure is a schematic diagram of the receiving circuit of the wide-band transceiver channel circuit of the present invention.

[0021] Figure 2 The figure is a schematic diagram of the transmitting circuit of the wide-band transceiver channel circuit of the present invention. DETAILED DESCRIPTION

[0022] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] At the same time, the meaning of "and / or" or "and / or" appearing in the full text includes three options. Taking "A and / or B" as an example, it includes option A, or option B, or an option in which both A and B are satisfied.

[0025] In addition, in this utility model, the descriptions of "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0026] Example 1

[0027] Reference Figure 1 , which is the first embodiment of the utility model, provides a wide-band transceiver channel circuit, the wide-band transceiver channel circuit comprising: a receiving circuit;

[0028] The receiving circuit includes a low-pass filter, a digitally controlled attenuator, a limiter, an LNA amplifier, a radio frequency switch, a segmented low-pass filter, a radio frequency switch, a low-pass filter, a mixer, a band-pass filter, a radio frequency amplifier, a band-pass filter, a mixer, a low-pass filter, a digitally controlled attenuator, a radio frequency amplifier, a digitally controlled attenuator, a radio frequency amplifier, a radio frequency switch, filters for selecting different bandwidths, a radio frequency switch, a radio frequency amplifier, and a low-pass filter, which are connected in sequence.

[0029] The digitally controlled attenuator achieves a gain control range of 1-3 levels, with each level being 30dB and the step being 1dB. The gain characteristic design achieves a gain control range of 3 levels with a digitally controlled attenuator, with each level being 30dB and the step being 1dB. The attenuator response time is very short, which can meet the switching requirements of all application scenarios.

[0030] The digitally controlled attenuators together form a three-stage AGC (automatic gain control) control circuit in the receiving circuit channel. The digitally controlled attenuators connected in sequence together form a three-stage AGC control circuit in the receiving channel. The first digitally controlled attenuator in the receiving circuit is called the RF AGC circuit, the second digitally controlled attenuator in the receiving circuit is called the IF AGC1 (automatic gain control one) circuit, and the third digitally controlled attenuator in the receiving circuit is called the IF AGC2 (automatic gain control two) circuit. The coordinated work of the three AGCs can achieve a maximum attenuation of 90dB to ensure the normal operation of the receiving channel under large signal conditions.

[0031] The limiter protects the receiving LNA (amplifier) ​​and other circuits to ensure that the receiving link is not damaged when a large signal is input.

[0032] The amplifier is in a linear state under small signals, and the channel provides a gain of no less than 45dB.

[0033] Filters in the receiving channel are mostly selected with small delay to meet the low delay requirements of the receiving channel.

[0034] The IF filter has four different bandwidths to choose from to cover application requirements of various bandwidth waveforms.

[0035] The radio frequency uses a three-level low-pass filter, which suppresses the image frequency by more than 80dB and can meet most application requirements.

[0036] The first intermediate frequency uses a bandpass filter, which suppresses the second intermediate frequency by more than 80dB, which can meet most application requirements.

[0037] In actual use, the receiving circuit adopts a superheterodyne architecture, and uses the post-stage signal detection circuit to detect the received signal strength in real time, and controls the multi-stage AGC circuit to adjust the signal amplitude. It has a high dynamic range while meeting the sensitivity requirements to achieve the reception of signals of various strengths.

[0038] Example 2

[0039] Reference Figure 1 and Figure 2 , which is the second embodiment of the present utility model, is different from the first embodiment in that:

[0040] Also included: a transmitting circuit;

[0041] The transmitting circuit includes a digitally controlled attenuator, a radio frequency amplifier, a tuning filter, and a radio frequency switch which are connected in sequence.

[0042] The transmitting circuit has a first-stage digitally controlled attenuator to ensure that the transmitting output amplitude can be adjusted to meet most application requirements.

[0043] By tuning the filter, you can effectively filter out spurious waves and harmonics and reduce interference to other devices.

[0044] By switching the RF switch at the transmitter, pulse modulation can be achieved to meet the relevant requirements of the waveform.

[0045] The characteristics of the integrated receiving and transmitting circuit and the wide-band receiving and transmitting channel are as follows: the frequency of the RF signal input to the receiving circuit RF port and the input and output of the transmitting circuit RF port is 30MHz to 2500MHz;

[0046] When the RF signal passes through the limiter and the three-stage digitally controlled attenuator, the high dynamic range of the RF signal can be guaranteed;

[0047] When the RF signal passes through low-pass, band-pass, low-pass and different bandwidth selection filters, it can effectively suppress the image frequency 80dBc and the intermediate frequency 80dBc, ensuring the high anti-interference performance of the circuit.

[0048] In actual use, the transmitting circuit adopts direct radio frequency transmission. Through the amplification and filtering circuits, it can not only ensure the amplitude of the output signal but also reduce the out-of-band interference signal.

[0049] The remaining structures are the same as those of Example 1.

[0050] It should be understood that these embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention. In addition, it should be understood that after reading the technical content of the present invention, those skilled in the art may make various changes, modifications and / or variations to the present invention, and all such equivalent forms also fall within the scope of protection defined by the appended claims of this application.

Claims

1. A wide-band transceiver channel circuit, characterized in that: include: receiving circuit; The receiving circuit includes a low-pass filter, a digitally controlled attenuator, a limiter, an LNA amplifier, a radio frequency switch, a segmented low-pass filter, a radio frequency switch, a low-pass filter, a mixer, a band-pass filter, a radio frequency amplifier, a band-pass filter, a mixer, a low-pass filter, a digitally controlled attenuator, a radio frequency amplifier, a digitally controlled attenuator, a radio frequency amplifier, a radio frequency switch, filters for selecting different bandwidths, a radio frequency switch, a radio frequency amplifier, and a low-pass filter, which are connected in sequence; Also included: a transmitting circuit; The transmitting circuit includes a digitally controlled attenuator, a radio frequency amplifier, a tuning filter, and a radio frequency switch which are connected in sequence.

2. The wideband transceiver channel circuit according to claim 1, wherein: The digitally controlled attenuator achieves a gain control range of 1-3 levels, wherein each level is 30 dB and the step is 1 dB.

3. The wideband transceiver channel circuit according to claim 1, wherein: The digitally controlled attenuators together form a three-stage AGC control circuit in the receiving circuit channel.

4. The wideband transceiver channel circuit according to claim 1, wherein: The frequencies of the radio frequency signals input to the radio frequency port of the receiving circuit and input and output to the radio frequency port of the transmitting circuit are 30 MHz to 2500 MHz.

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