CN219780137U - Multichannel short wave receiving and transmitting circuit - Google Patents

Abstract

The utility model discloses a multichannel short wave receiving and transmitting circuit, which belongs to the technical field of radio frequency receiving and transmitting conversion and comprises a switch module, a filter module and a frequency mixing module, wherein the switch module is divided into a first switch module and a second switch module, the filter module is divided into a first band filter module and a second filter module, the output end of the first switch module is connected with the input end of the first filter module in series, the output end of the first filter module is connected with the input end of the second switch module in series, the output end of the second switch module is connected with the input end of the frequency mixing module in series, the output end of the frequency mixing module is connected with the second filter module in series, seven first filter modules are provided with seven connecting ports, and the output end of the first switch module and the input end of the second switch module can ensure that the frequency mixing module works in a frequency range and obtain very good frequency conversion performance requirements.

Description

Multichannel short wave receiving and transmitting circuit

Technical Field

The utility model belongs to the technical field of radio frequency transceiving conversion, and particularly relates to a multichannel short wave transceiving circuit.

Background

In a microwave millimeter wave radio frequency receiving and transmitting system, radio frequency input signals generally need to be subjected to frequency conversion, and local oscillation frequencies are often far away from the radio frequency input frequencies, so that the later-stage circuit can remove unwanted information such as mixing spurs, image frequency, out-of-band noise and the like of a receiver, and purer frequency signals can be obtained, and therefore the identification capacity and anti-interference capacity of the receiver are improved.

In the radio frequency receiving and transmitting frequency conversion circuit, because the working frequency is very high, the frequency can not be selected to be too close to the radio frequency after frequency conversion, otherwise, signals such as radio frequency input and harmonic waves thereof are directly transmitted to a lower-level circuit through the frequency mixing circuit, and the signals exist in or near a frequency band as spurious, so that interference is caused, and a receiver can not work normally.

However, the higher the working frequency of the receiver after frequency conversion is, the higher the design requirement on the circuit is, the higher the supporting requirement on the circuit technology is, and the higher the corresponding cost of devices and raw materials is, so that the traditional circuit design method is difficult to realize, and the design difficulty and the production cost of the product are greatly improved.

Disclosure of Invention

Aiming at the problems that the higher the working frequency is after the frequency conversion of the existing receiver, the higher the design requirement on a circuit is, the traditional circuit design method is difficult to realize, and the design difficulty and the production cost of a product are improved, the utility model provides a multichannel short wave receiving and transmitting circuit.

In order to solve the problems, the utility model adopts the following technical scheme:

the utility model provides a multichannel shortwave receiving and dispatching circuit, includes switch module, wave filter module and frequency mixing module, switch module divide into first switch module and second switch module, the wave filter module divide into first wave filter module and second wave filter module, first switch module output with first wave filter module input is established ties, first wave filter module output with second switch module input is established ties, second switch module output with the input of frequency mixing module is established ties, the frequency mixing module output with second wave filter module is established ties, first wave filter module totally has seven, first switch module output with second switch module input all be equipped with first wave filter module assorted seven connection port, seven connect in parallel each other between the first wave filter module.

Preferably, the first filter module employs an LC filter.

Preferably, the working frequency of the first filter module for receiving the radio frequency input signal is 3 MHz-45 MHz, and the variable frequency output frequency of the second filter module for receiving the radio frequency is 50MHz.

Preferably, the working frequency of the radio frequency input signal transmitted by the first filter module is 3 MHz-45 MHz, and the variable frequency output frequency of the radio frequency transmitted by the second filter module is 3 MHz-45 MHz.

Further, the local oscillation frequency of the mixing module is 53 MHz-95 MHz.

A multichannel short wave receiving and transmitting circuit receives signals through multichannel receiving channels, one of the multichannel receiving channels can also be used as a transmitting channel, the first switch module divides an input signal into seven sections, the input signal is mixed by the mixing module after being filtered by the corresponding filter module, the working frequency of frequency conversion is reduced, meanwhile, extra frequency conversion strays and other interferences cannot be introduced after the frequency conversion, the design difficulty of a band-pass filter after the frequency conversion is reduced, the performance index of a receiver is guaranteed to be used by reducing the frequency bandwidth through devices, the device selection is facilitated, the implementation is easy, and the production cost is reduced.

Advantageous effects

Compared with the prior art, the utility model provides a multichannel short wave receiving and transmitting circuit, which has the following beneficial effects:

(1) According to the utility model, different input frequencies are replaced to different filters for filtering through switch selection, so that the efficiency of the filters for suppressing spurious input frequencies and other useless signals is greatly improved, the design difficulty of the band-pass filters after mixing is reduced, and the anti-interference capability and the identification capability of the receiver are improved;

(2) The utility model adopts the low local oscillator frequency conversion technology to reduce the frequency after frequency conversion, and the working frequency is not required to be far higher than the radio frequency input frequency in the working frequency bandwidth because the working frequency is lower, thereby reducing the design difficulty of an internal circuit and the supporting requirement of a production process;

(3) The utility model replaces the input frequency to different filters for filtering through the switch selection, reduces the design difficulty of an internal circuit, reduces the requirement of the broadband performance index of the device, reduces the frequency bandwidth usage through the device, and facilitates the device model selection, thereby reducing the raw material cost.

Drawings

Fig. 1 is a schematic circuit distribution diagram of a multichannel short wave transceiver circuit according to the present utility model;

fig. 2 is a schematic diagram of a connection structure of a multichannel short-wave transceiver circuit according to the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments.

In the description of the present utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present utility model and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Examples:

referring to fig. 1, a channel shortwave transceiver circuit divides a signal into multiple frequency inputs by a single frequency conversion, and frequency conversion output can be realized by using a mixer and a local oscillator input through switch control.

Through singlechip control, the clutter signals in the input signals are filtered through corresponding filters respectively, then the input signals are mixed with corresponding local oscillator inputs through a switch, variable frequency output is realized, the input signals are put into different filters for filtering through the switch, so that the design difficulty of the filters can be reduced, and meanwhile, good clutter suppression performance is obtained, thereby realizing the receiving of short waves, and the input signals can also be applied to a power amplifier circuit, so that the transmitting function of the circuit is realized.

The working principle of the short wave receiving and transmitting circuit is that the working frequency of the receiving radio frequency input signal is 3 MHz-45 MHz, and the corresponding variable frequency output frequency is designed to be 50MHz; the working frequency of the transmitting radio frequency input signal is 3 MHz-45 MHz, and the corresponding output frequency is designed to be 3 MHz-45 MHz, so that the corresponding local oscillation frequency is respectively 53 MHz-95 MHz.

The band-pass filters 1-7 adopt LC filters, the band-pass filter 8 adopts a cavity filter, the insertion loss is small, the inhibition is high, and the volume is small.

Band-pass filter	Center frequency/MHz	Passband bandwidth/MHz	Insertion loss/dB
				1	4.5	3	1.4
2	8	4	1.4
				3	13	6	1.4
4	19	6	1.4
				5	25.5	7	1.4
6	34	8	1.4
				7	41	8	1.4
8	50	1.2	2

When receiving an input signal RFin and working in a frequency band of 3 MHz-6 MHz, a switch 1 and a switch 2 select to switch the input frequency to a filter BPF1, and the input local oscillation frequency LO is 53 MHz-56 MHz;

when receiving an input signal RFin and working in a frequency band of 6 MHz-10 MHz, a switch 1 and a switch 2 select to switch the input frequency to a filter BPF2, and the input local oscillation frequency LO is 56 MHz-60 MHz;

when receiving an input signal RFin and working in a frequency band of 10 MHz-16 MHz, a switch 1 and a switch 2 select to switch the input frequency to a filter BPF3, and the input local oscillation frequency LO is 60 MHz-66 MHz;

when receiving an input signal RFin and working in a frequency band of 16 MHz-22 MHz, a switch 1 and a switch 2 select to switch the input frequency to a filter BPF4, and the input local oscillation frequency LO is 66 MHz-72 MHz;

when receiving an input signal RFin and working at a frequency band of 22 MHz-29 MHz, a switch 1 and a switch 2 select to switch the input frequency to a filter BPF5, and the input local oscillation frequency LO is 72 MHz-79 MHz;

when receiving an input signal RFin and working in the frequency range of 29 MHz-37 MHz, the switch 1 and the switch 2 select to switch the input frequency to the filter BPF6, and the input local oscillation frequency LO is 79 MHz-87 MHz;

when the received input signal RFin works in the frequency range of 37 MHz-45 MHz, the switch 1 and the switch 2 select to switch the input frequency to the filter BPF7, and the input local oscillation frequency LO is 87 MHz-95 MHz.

After final mixing, the mixture is output by a Radio Frequency (RF) port, and then filtered by a BPF8 to obtain an RFout signal with a center frequency of 50MHz.

When the transmitting input signal works at 3 MHz-45 MHz, the signal is directly amplified by a power amplifier and then output.

The receiving and transmitting circuit adopts low local oscillation frequency, and the image frequency corresponding to the input signal is RF+LO respectively.

The input frequency is received at 3 MHz-45 MHz, the frequency is converted to 50MHz, the input frequency and the 2 nd harmonic thereof are close to 45MHz, but the 2 nd harmonic of the input frequency and out-of-band mixing spurious and interference signals can be well restrained by the band-pass filters BPF 1-7 before mixing, meanwhile, the image frequency is RF+LO, and the band-pass filters are far away from the working frequency, so that the front-end circuit filters can conveniently restrain the image frequency.

In the short wave receiving and transmitting circuit, the input signal is divided into seven sections, and the frequency mixing is carried out after the input signal is filtered by the corresponding filter, so that the design difficulty of the internal circuit is reduced.

The receiving frequency conversion circuit has the advantages that the working frequency of the receiving frequency conversion circuit is not too high after frequency conversion, and the receiving frequency conversion circuit does not need to work far higher than the radio frequency input frequency in the working frequency bandwidth, so that the circuit design difficulty and the production and development cost are reduced.

Secondly, the receiving frequency is selected by a switch to enter the corresponding filter respectively, and the output signal after frequency conversion works at a fixed frequency, so that the filter is convenient to suppress mixing spurious, image interference and other useless signals, the design difficulty of the band-pass filter after mixing is reduced, and the band-pass filter is easy to realize.

Thirdly, the input signal can also realize the transmitting function of the circuit through the power amplifier circuit, so that the purposes of receiving and transmitting are realized by the short wave receiving and transmitting circuit, the circuit is simple, efficient and practical, and the cost is saved.

The utility model is applied to the technical field of radio frequency transceiver conversion, and the transceiver circuit realized by the mode can obtain very good frequency conversion performance requirements under the condition of ensuring the working in a frequency range, and has the advantages of simple circuit, high efficiency, practicability, low cost and convenient production.

The foregoing is only a preferred embodiment of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art, who is within the scope of the present utility model, should make equivalent substitutions or modifications according to the technical scheme of the present utility model and the inventive concept thereof, and should be covered by the scope of the present utility model.

Claims (5)

1. The utility model provides a multichannel shortwave receiving and dispatching circuit, its characterized in that includes switch module, wave filter module and mixing module, switch module divide into first switch module and second switch module, the wave filter module divide into first wave filter module and second wave filter module, first switch module output with first wave filter module input is established ties, first wave filter module output with second switch module input is established ties, second switch module output with mixing module's input is established ties, mixing module output with second wave filter module establishes ties, first wave filter module total seven, first switch module output with second switch module input all be equipped with first wave filter module assorted seven connecting port, seven between the first wave filter module are parallelly connected each other.

2. The multi-channel short wave transceiver circuit of claim 1, wherein said first filter module employs LC filters.

3. The multi-channel short wave transceiver circuit of claim 1, wherein the first filter module receives the radio frequency input signal at a working frequency of 3 MHz-45 MHz, and the second filter module receives the radio frequency at a variable frequency output frequency of 50MHz.

4. The multi-channel short wave transceiver circuit of claim 1, wherein the operating frequency of the first filter module transmitting radio frequency input signal is 3 MHz-45 MHz, and the output frequency of the second filter module transmitting radio frequency is 3 MHz-45 MHz.

5. The multi-channel short wave transceiver circuit of claim 1, wherein the local oscillation frequency of the mixing module is 53 MHz-95 MHz.