Multi-channel dual-band microwave receiver front end

Abstract

The invention belongs to the technical field of multi-channel microwave receivers, and particularly relates to a front end of a multi-channel dual-band microwave receiver. The radio frequency channel assembly is composed of more than two independent radio frequency channel modules. The local oscillator and calibration source assembly is connected with the radio frequency channel assembly and provides high-low wave band up-down conversion local oscillator signals. The power supply and control assembly provides required power supply and control enabling for each unit; the radio frequency channel module is used for receiving high and low wave band signals of an antenna, performing frequency mixing twice with local oscillator signals to obtain intermediate frequency signals and outputting the intermediate frequency signals, and receiving processing of each path of radio frequency signals and final output of the intermediate frequency signals are independently realized in the same radio frequency channel module. The system has the beneficial effects that the channel is modularized, and the anti-interference capability is high; the number of channels of the radio frequency channel assembly is adjustable, and flexibility and expandability are better; high and low wavebands adopt two frequency mixing modes, so that the antenna has the advantages of low cost, small size and low power consumption; the metal substrate is partially replaced by aluminum and silicon, the product reliability is high, and wide application is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of multi-channel microwave receivers, and in particular relates to a multi-channel dual-band microwave receiver front end. Background Art

[0002] The multi-channel microwave receiver is a key component that connects the radar receiving antenna and the intermediate frequency processor, and realizes the amplification, frequency conversion and filtering functions of the weak signal received by the antenna. Due to the complexity of radar applications, especially the array antennas of radar applications such as direction finding and positioning, microwave arrays are required to realize the synchronous reception of multi-channel antenna signals, design more channels in the same module, and have high requirements for the amplitude and phase consistency and isolation between channels of each receiving channel.

[0003] At present, the implementation scheme of multi-channel microwave receivers is to use PIN diode switch combination in the same module to realize multi-channel microwave frequency selection receiving components, and to use the local oscillator signal to perform a down-conversion to obtain the intermediate frequency signal. The existing technical scheme has the following deficiencies: (1) The amplitude and phase consistency and channel isolation between each receiving channel are poor. More channels are designed in the same module, and the channels are not perfectly physically isolated. The coupling and crosstalk between channels are large, and the anti-interference ability is not ideal. (2) After the number of antennas or the array requirements are adjusted, the microwave receiver part needs to be redeveloped. It does not have the ability and flexibility of rapid combination and reconstruction, and its versatility is poor. (3) A mixing method is used in circuit design, which has high power consumption requirements for the local oscillator, and the circuit design is complex, large in size, and high in cost. (4) There are differences in the materials of microwave circuits and RF devices. The assembly process is unstable in a large temperature difference environment, and the product reliability is poor. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a multi-channel dual-band microwave receiver front end with modular channels, adjustable number of channels, strong anti-interference ability, and can effectively improve the signal crosstalk problem between channels and improve product reliability.

[0005] The technical solution adopted by the present invention to solve the technical problem is as follows: a multi-channel dual-band microwave receiver front end, comprising:

[0006] A radio frequency channel component, consisting of two or more independent radio frequency channel modules;

[0007] A local oscillator and calibration source component is connected to the RF channel component to provide the RF channel module with a local oscillator signal for up- and down-conversion of high and low bands and a calibration signal for a calibration mode;

[0008] A power supply and control component, connected to the RF channel component and the local oscillator and calibration source component, for providing working power and control enable to the local oscillator and calibration source component and the RF channel module;

[0009] The RF channel module is used to receive the high and low band signals of the antenna, obtain the intermediate frequency signal by mixing it twice with the local oscillator signal and output it, and the reception processing of each RF signal and the final output of the intermediate frequency signal are independently implemented in the same RF channel module.

[0010] Preferably, the RF channel module has a built-in mixing circuit for receiving local oscillator signals; the mixing circuit adopts two mixing schemes, one local oscillator switches high and low frequency sweeping local oscillator modes according to high and low bands, and the second local oscillator switches high and low frequency spot local oscillators according to high and low bands.

[0011] Preferably, the high-band signal is mixed once by a local oscillator driven by a low-frequency sweeping local oscillator to obtain a low-band fixed intermediate frequency, and then the second intermediate frequency is obtained by a second local oscillator using a high-frequency local oscillator; the low-band signal is mixed once by a local oscillator driven by a high-frequency sweeping local oscillator to obtain a high-band fixed intermediate frequency, and then the second intermediate frequency is obtained by a second local oscillator using a low-frequency local oscillator.

[0012] Preferably, the RF channel module also has a built-in gating circuit, which is connected before the mixing circuit. The gating circuit receives antenna signals and calibration signals. The gating circuit is a gating control switch circuit with two input sources, one of which is used for gating high-band antenna signals and calibration signals through the first switch, and the other is used for gating low-band antenna signals and calibration signals through the second switch.

[0013] Preferably, the RF channel module also has built-in RF conditioning circuit and intermediate frequency conditioning circuit, the RF conditioning circuit is connected between the selection circuit and the mixing circuit; the intermediate frequency conditioning circuit is connected after the mixing circuit to perform intermediate frequency output.

[0014] Preferably, the metal substrate of the gating circuit, the radio frequency conditioning circuit, the mixing circuit and / or the intermediate frequency conditioning circuit is made of aluminum silicon.

[0015] Preferably, in the intermediate frequency conditioning circuit, the filter is connected to the amplifier, and the amplifier is connected to the attenuator.

[0016] Preferably, it also includes: a power division component, which is connected between the local oscillator and calibration source component and the RF channel component, performs power division on the local oscillator signal and / or the calibration signal, divides one signal into multiple signals, and provides a local oscillator signal and / or a calibration signal for each RF channel module.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The modular design of the receiving channel physically isolates the RF signal path, solves the crosstalk problem of signal transmission, and has strong anti-interference ability;

[0019] 2. The modular receiving channel solution is adopted. The receiving and processing of each RF signal and the final output of the intermediate frequency signal are independently implemented in one RF channel module, which is convenient for channel expansion according to the number of antenna arrays, effectively improving the flexibility of the receiver;

[0020] 3. In circuit design, two mixing modes are used for high and low bands to achieve time-sharing up and down frequency conversion of high and low bands, which reduces the requirements for local oscillators, simplifies circuit design, and achieves the purpose of low cost, small size and low power consumption;

[0021] 4. Aluminum silicon materials are used as partial replacements on the metal substrate of key microwave circuits to ensure that its thermal expansion coefficient is similar to that of RF devices, improve the stability of the assembly process in a large temperature difference environment, and improve product reliability;

[0022] In summary, the multi-channel dual-band microwave receiver front end has modular channels and strong anti-interference ability; the number of channels of the RF channel component is adjustable, and the flexibility and scalability are better; two mixing methods are used for high and low bands, which has the advantages of low cost, small size and low power consumption; the metal substrate is partially replaced by aluminum silicon, and the product has high reliability, which is conducive to wide application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the front-end structure of a multi-channel dual-band microwave receiver;

[0024] Figure 2 This is the circuit block diagram of the RF channel module;

[0025] Figure 3 It is a diagram of the mixing scheme;

[0026] Figure 4 This is a schematic diagram of the location of the key microwave circuit in Example 2. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0028] Example 1: Combination Figure 1 and Figure 3It is understood that a multi-channel dual-band microwave receiver front end includes: a radio frequency channel component, which is composed of more than two independent radio frequency channel modules; a local oscillator and calibration source component, which is connected to the radio frequency channel component and is used to provide the radio frequency channel module with a local oscillator signal for up-conversion of high and low bands and a calibration signal of a calibration mode; a power supply and control component, which is connected to the radio frequency channel component and the local oscillator and calibration source component, and is used to provide working power and control enable to the local oscillator and calibration source component and the radio frequency channel module; the radio frequency channel module is used to receive the high and low band signals of the antenna, and obtain the intermediate frequency signal by mixing it twice with the local oscillator signal and output it, and the reception and processing of each radio frequency signal and the final output of the intermediate frequency signal are independently realized in the same radio frequency channel module. The modular design of the receiving channel physically isolates the radio frequency signal path, solves the crosstalk problem of signal transmission, and has strong anti-interference ability; the modular receiving channel solution is adopted, and the signal reception processing and output functions are independently realized, which is convenient for channel expansion according to the number of antenna arrays, and effectively improves the flexibility of the receiver. The RF channel module has a built-in mixing circuit for receiving local oscillator signals; the mixing circuit adopts two mixing schemes, one local oscillator switches between high and low frequency sweeping local oscillator modes according to high and low bands, and the other local oscillator switches between high and low frequency spot local oscillators according to high and low bands. The mixing circuit is pre-installed with a band selection switch, that is, Figure 3 The A switch and the B switch are used to select the mixing path. The two mixing schemes are as follows: the high-band signal is mixed once through a first oscillator using a low-frequency sweeping local oscillator to obtain a low-band fixed intermediate frequency, and then through a second local oscillator using a high-frequency local oscillator to obtain a second intermediate frequency; the low-band signal is mixed once through a first oscillator using a high-frequency sweeping local oscillator to obtain a high-band fixed intermediate frequency, and then through a second local oscillator using a low-frequency local oscillator to obtain a second intermediate frequency. The frequency conversion scheme is optimized by multi-intermediate frequency design and high-low local oscillator mixing. This mixing method realizes the high and low bands time-sharing up and down conversion to obtain the intermediate frequency signal. The sweeping local oscillator range is controllable and less than 1 octave, which reduces the requirements for the local oscillator, simplifies the circuit design, and achieves the purpose of low cost, small size, and low power consumption.

[0029] Example 2: Recombination Figure 2 It is understood that, based on Example 1, the RF channel module also includes a gating circuit, a RF conditioning circuit and an intermediate frequency conditioning circuit, and each circuit is connected in series. The RF conditioning circuit is connected between the gating circuit and the mixing circuit; the intermediate frequency conditioning circuit is connected after the mixing circuit to output the intermediate frequency. The gating circuit receives antenna signals and calibration signals, and the gating circuit is a gating control switch circuit of two input sources, one of which is used for gating high-band antenna signals and calibration signals through the first switch, and the other is used for gating low-band antenna signals and calibration signals through the second switch.

[0030] Working principle: Combination Figure 1-3It is understood that in a microwave receiver front end with multiple receiving channels, each independent RF channel module receives a RF signal, which has high and low bands. Three signal sources, namely, high-band antenna signal, low-band antenna signal and calibration signal, enter the gating circuit, which is a gating control switch circuit for two input sources, one of which is used for gating high-band antenna signal and calibration signal through a first switch, and the other is used for gating low-band antenna signal and calibration signal through a second switch; the selected signal enters the RF conditioning circuit, in which it first enters the band selection switch for segmented filtering according to the operating frequency to realize the pre-selection filtering function of the input signal, filter out the image frequency signal to improve the anti-interference ability, and then select the amplification mode or attenuation mode according to the signal power range; the signal enters the mixing circuit after passing through the RF conditioning circuit, and is mixed twice with the local oscillator signal emitted by the local oscillator component and output by the power division component; the signal enters the intermediate frequency conditioning circuit after passing through the mixing circuit, and the intermediate frequency conditioning circuit filters, amplifies, and program-controlled attenuates the intermediate frequency signal, and finally outputs the intermediate frequency signal to the intermediate frequency processor. Figure 1 The n RF channel modules can process n antenna signals respectively and finally generate n intermediate frequency outputs.

[0031] Example 3: Based on Example 2, gallium arsenide is a widely used RF device material, and its thermal expansion coefficient is a key parameter for evaluating its stability. The difference in thermal expansion coefficients between the chip and the microwave circuit will cause the connection between the chip and other components to fail, reducing the overall system stability. The metal substrate of the microwave circuit is generally aluminum material, and the thermal expansion coefficient of aluminum is 23.6 ppm / ℃, while the thermal expansion coefficient of gallium arsenide is 5.7 ppm / ℃, which is quite different. The thermal expansion coefficient of aluminum silicon material can be controlled between 5 ppm / ℃ and 20 ppm / ℃. Aluminum silicon material is used to partially replace the metal substrate of the key microwave circuit, and the replacement position is Figure 4 The shaded parts of the three parts can effectively reduce the stress of the chip caused by temperature changes during operation, ensure the stability of the assembly process under a large temperature difference environment, and improve product reliability.

[0032] The independent channel design in the present invention, on the one hand, physically isolates the RF signal channel to avoid the crosstalk problem of signal transmission, and on the other hand, the modular setting of the RF channel has better flexibility and scalability, and enhances the array reconstruction capability. Two mixing methods are used for high and low bands. The multi-IF design and high and low local oscillator mixing methods optimize the frequency conversion scheme to achieve time-sharing up and down frequency conversion of high and low bands. The frequency range of the swept local oscillator can be controlled, which reduces the difficulty of implementing the local oscillator and is conducive to the selection of devices and the design of interconnected circuits. Aluminum silicon material is used for partial replacement on the metal substrate of the key microwave circuit to ensure that its thermal expansion coefficient is similar to that of the RF device, improve the stability of the assembly process in a large temperature difference environment, and improve product reliability.

[0033] In one embodiment, in the intermediate frequency conditioning circuit, the filter is connected to the amplifier, and the amplifier is connected to the attenuator.

[0034] In one embodiment, it also includes: a power division component, which is connected between the local oscillator and calibration source component and the RF channel component, performs power division on the local oscillator signal and / or the calibration signal, divides one signal into multiple signals, and provides a local oscillator signal and / or a calibration signal for each RF channel module.

[0035] In one embodiment, the metal substrate of the gating circuit, the radio frequency conditioning circuit, the mixing circuit and / or the intermediate frequency conditioning circuit is made of aluminum silicon.

[0036] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A multi-channel dual-band microwave receiver front end, characterized in that: include: A radio frequency channel component, consisting of two or more independent radio frequency channel modules; A local oscillator and calibration source component is connected to the RF channel component to provide the RF channel module with a local oscillator signal for up- and down-conversion of high and low bands and a calibration signal for a calibration mode; A power supply and control component, connected to the RF channel component and the local oscillator and calibration source component, for providing working power and control enable to the local oscillator and calibration source component and the RF channel module; The RF channel module is used to receive the high and low band signals of the antenna, obtain the intermediate frequency signal by mixing it twice with the local oscillator signal and output it, and the reception processing of each RF signal and the final output of the intermediate frequency signal are independently implemented in the same RF channel module.

2. The multi-channel dual-band microwave receiver front end according to claim 1, characterized in that: The RF channel module has a built-in mixing circuit for receiving local oscillator signals; the mixing circuit adopts two mixing schemes, one local oscillator switches high and low frequency sweeping local oscillator modes according to high and low bands, and the second local oscillator switches high and low frequency spot local oscillators according to high and low bands.

3. The multi-channel dual-band microwave receiver front end according to claim 2, characterized in that: The high-band signal is mixed once through a local oscillator using a low-frequency sweep local oscillator to obtain a low-band fixed intermediate frequency, and then passed through a second local oscillator using a high-frequency local oscillator to obtain a second intermediate frequency; the low-band signal is mixed once through a local oscillator using a high-frequency sweep local oscillator to obtain a high-band fixed intermediate frequency, and then passed through a second local oscillator using a low-frequency local oscillator to obtain a second intermediate frequency.

4. The multi-channel dual-band microwave receiver front end according to claim 2 or 3, characterized in that: The RF channel module also has a built-in gating circuit, which is connected in front of the mixing circuit. The gating circuit receives antenna signals and calibration signals. The gating circuit is a gating control switch circuit with two input sources, one of which is used for gating high-band antenna signals and calibration signals through the first switch, and the other is used for gating low-band antenna signals and calibration signals through the second switch.

5. The multi-channel dual-band microwave receiver front end according to claim 4, characterized in that: The RF channel module also has built-in RF conditioning circuit and intermediate frequency conditioning circuit. The RF conditioning circuit is connected between the selection circuit and the mixing circuit; the intermediate frequency conditioning circuit is connected after the mixing circuit to perform intermediate frequency output.

6. The multi-channel dual-band microwave receiver front end according to claim 5, characterized in that: The metal substrate of the gating circuit, the radio frequency conditioning circuit, the mixing circuit and / or the intermediate frequency conditioning circuit is made of aluminum silicon.

7. The multi-channel dual-band microwave receiver front end according to claim 5, characterized in that: In the intermediate frequency conditioning circuit, the filter is connected to the amplifier, and the amplifier is connected to the attenuator.

8. The multi-channel dual-band microwave receiver front end according to any one of claims 1 to 3, characterized in that: Also includes: A power division component is connected between the local oscillator and calibration source component and the RF channel component, performs power division on the local oscillator signal and / or the calibration signal, divides one signal into multiple signals, and provides a local oscillator signal and / or a calibration signal for each RF channel module.

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