E-band frequency conversion channel circuit

Abstract

The invention provides an E-band frequency conversion channel circuit, which relates to the technical field of E-band frequency conversion and comprises a local oscillator signal generator, a first E-band frequency conversion channel, a second E-band frequency conversion channel, a first frequency multiplier and a second frequency multiplier. The local oscillator signal generator outputs two local oscillator signals; each of the first E-band frequency conversion channel and the second E-band frequency conversion channel comprises a first frequency conversion sub-module and a second frequency conversion sub-module; a second output signal of the first local oscillator signal is input into a first frequency conversion sub-module of a first E-band frequency conversion channel through a first frequency multiplier, and a second output signal of the second local oscillator signal is input into a second frequency conversion sub-module of the first E-band frequency conversion channel; a first output signal of the first local oscillator signal is connected with a first frequency conversion sub-module of a second E-band frequency conversion channel through a second frequency multiplier, and a first output signal of the second local oscillator signal is input to a second frequency conversion sub-module of the second E-band frequency conversion channel. According to the invention, the integration level and consistency of the system are improved while the dual-channel tracking capability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of E-band frequency conversion, in particular to an E-band frequency conversion channel circuit. BACKGROUND

[0002] With the development of technology, the communication frequency is used higher and higher.

[0003] The existing tracking frequency converter technology mostly covers low frequency, and is only suitable for application scenarios with low frequency and single channel use. When double-channel tracking of E-band (81-86GHz) signals is required, the existing tracking frequency conversion is difficult to meet the demand. Although there are E-band corresponding modules on the market, most of them have relatively single functions and can only complete a single function. If you want to combine a double-channel tracking frequency conversion module that meets the demand, you need to combine multiple modules, which is high in cost and complex in technology. That is, in the occasion where double-channel tracking frequency conversion is required, the existing scheme often needs to be implemented by combining multiple independent modules, which not only increases the system cost and volume, but also brings a series of technical problems such as module interface matching, phase consistency, noise control, etc. The system implementation complexity is high, and it is difficult to meet the application requirements of high-frequency communication, radar, etc. with high integration and performance consistency.

[0004] Therefore, it is necessary to optimize the E-band frequency conversion technology to improve the double-channel tracking capability while improving the integration and consistency of the system. SUMMARY

[0005] The purpose of the present application is to provide an E-band frequency conversion channel circuit that can improve the double-channel tracking capability while improving the integration and consistency of the system.

[0006] The present application is implemented by the following technical solutions: An E-band frequency conversion channel circuit, comprising a local oscillator signal generator, a first E-band frequency conversion channel, a second E-band frequency conversion channel, a first frequency multiplier, and a second frequency multiplier; The local oscillator signal generator outputs a first local oscillator signal and a second local oscillator signal, and the first local oscillator signal and the second local oscillator signal are both divided into two output signals; The first E-band frequency conversion channel and the second E-band frequency conversion channel have consistent structures, and both comprise a first frequency conversion sub-module and a second frequency conversion sub-module connected in series; The second output signal of the first local oscillator signal is input to the first frequency conversion sub-module of the first E-band frequency conversion channel through the first frequency multiplier, and the second output signal of the second local oscillator signal is input to the second frequency conversion sub-module of the first E-band frequency conversion channel; The first output signal of the first local oscillator signal is input to the first frequency conversion sub-module of the second E-band frequency conversion channel through a second frequency multiplier, and the first output signal of the second local oscillator signal is input to the second frequency conversion sub-module of the second E-band frequency conversion channel.

[0007] Preferably, the local oscillator signal generator comprises a constant temperature crystal oscillator, a plurality of phase-locked loops and a plurality of power dividers. The output end of the constant temperature crystal oscillator is connected to the input end of the first phase-locked loop and the input end of the third phase-locked loop, and the output end of the first phase-locked loop is connected to the input end of the second phase-locked loop. The output end of the second phase-locked loop is connected to the input end of the first power divider, and the output end of the first power divider outputs two outputs of the first local oscillator signal. The output end of the third phase-locked loop is connected to the input end of the second power divider, and the output end of the second power divider outputs two outputs of the second local oscillator signal.

[0008] Preferably, the first frequency conversion sub-module comprises a waveguide filter module, a wave-to-wave conversion module, a low-noise amplifier, a matching module and a first frequency conversion network. In the first E-band frequency conversion channel, the second output signal of the first local oscillator signal is input to the first frequency conversion network through a first frequency multiplier. In the second E-band frequency conversion channel, the first output signal of the first local oscillator signal is input to the first frequency conversion network through a second frequency multiplier. The waveguide filter module, the wave-to-wave conversion module, the low-noise amplifier, the matching module and the first frequency conversion network are connected in series.

[0009] Preferably, the first frequency conversion network comprises a first mixer and a second Π attenuator, and the matching module adopts a first Π attenuator. The output end of the first Π attenuator is connected to the input end of the first mixer, the output end of the first mixer is connected to the input end of the second Π attenuator, and the output end of the second Π attenuator is the output end of the first frequency conversion network.

[0010] Preferably, the wave-to-wave conversion module adopts a microstrip E-plane probe, and the electromagnetic field signal is coupled into the microstrip through the microstrip E-plane probe.

[0011] Preferably, the size optimization method of the microstrip E-plane probe is: The length and width of the microstrip E-plane probe and the distance between the microstrip E-plane probe and the waveguide short-circuit surface are taken as optimization variables through simulation modeling. The optimization target is to simultaneously satisfy that the reflection coefficient is not greater than a preset reflection coefficient threshold and the transmission coefficient is not less than a preset transmission coefficient threshold within the entire working frequency band of 81-86 GHz.

[0012] Preferably, the reflection coefficient threshold is -20dB, and the transmission coefficient threshold is -0.2dB.

[0013] Preferably, the second E-band frequency conversion channel comprises a first filter, a first amplifier, a second frequency conversion network, a second filter, an attenuator and a second amplifier. In the first E-band frequency conversion channel, a second output signal of the second local oscillator signal is input to the second frequency conversion network. In the second E-band frequency conversion channel, a first output signal of the second local oscillator signal is input to the second frequency conversion network. The first filter, the first amplifier, the second frequency conversion network, the second filter, the attenuator and the second amplifier are sequentially connected in series.

[0014] Preferably, a third Π attenuator is arranged as a matching module at the front end of the second frequency conversion network, and the second frequency conversion network comprises a second mixer and a fourth Π attenuator. An output end of the third Π attenuator is connected to an input end of the second mixer, an output end of the second mixer is connected to an input end of the fourth Π attenuator, and an output end of the fourth Π attenuator is an output end of the second frequency conversion network.

[0015] Preferably, each element in the first E-band frequency conversion channel and the second E-band frequency conversion channel is arranged in an independent cavity, so as to avoid mutual interference.

[0016] The technical scheme of the present application has at least the following advantages and beneficial effects: The present application breaks through the limitation of single channel and single function of the traditional frequency converter, realizes high-integration dual-channel tracking frequency conversion function in the E-band, and the system has two completely independent signal links for processing data of two channels, which is suitable for multi-channel synchronous measurement, tracking and communication scenarios. The present application adopts a unified local oscillator signal generator to provide four local oscillator outputs, ensures the phase consistency and frequency synchronization between channels, and helps to improve the stability and reliability of the dual-channel system. The four local oscillator signals of the present application correspond to two channels of up-conversion and down-conversion respectively, support independent debugging and optimization of each link, and facilitate link compensation, power balance or dynamic adjustment in complex channel environment. Each channel of the present application has complete receiving and transmitting paths, and each part is designed reasonably and has simple structure, which has the advantages of reducing system size, design complexity and assembly difficulty, and is suitable for integrated packaging and mass production. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The circuit principle diagram of the E-band frequency conversion channel circuit provided for the embodiment 1 of the present application. Figure 2 The circuit principle diagram of the local oscillator signal generator provided for the embodiment 1 of the present application is shown in the figure; Figure 3 The circuit principle diagram of the first frequency conversion network provided for the embodiment 1 of the present application is shown in the figure; Figure 4 The circuit principle diagram of the second frequency conversion network provided for the embodiment 1 of the present application is shown in the figure; Figure 5 The setting diagram of the wave conversion module provided for the embodiment 1 of the present application is shown in the figure; Figure 6 The diagram of the case that the elements provided for the embodiment 1 of the present application are respectively arranged in independent cavities is shown in the figure. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0019] Embodiment 1 The present embodiment provides an E-band frequency conversion channel circuit, referring to Figure 1 , which comprises a local oscillator signal generator, a first E-band frequency conversion channel, a second E-band frequency conversion channel, a first frequency multiplier and a second frequency multiplier. The local oscillator signal generator outputs a first local oscillator signal and a second local oscillator signal, and both the first local oscillator signal and the second local oscillator signal are divided into two output signals. The first E-band frequency conversion channel and the second E-band frequency conversion channel have consistent structures, and both comprise a first frequency conversion sub-module and a second frequency conversion sub-module connected in series. The second output signal of the first local oscillator signal is input to the first frequency conversion sub-module of the first E-band frequency conversion channel through the first frequency multiplier, and the second output signal of the second local oscillator signal is input to the second frequency conversion sub-module of the first E-band frequency conversion channel. The first output signal of the first local oscillator signal is input to the first frequency conversion sub-module of the second E-band frequency conversion channel through the second frequency multiplier, and the first output signal of the second local oscillator signal is input to the second frequency conversion sub-module of the second E-band frequency conversion channel.

[0020] In the embodiment, the local oscillator signal generator outputs two local oscillator signals, and the embodiment also includes two frequency conversion channels, the first local oscillator signal of the local oscillator signal generator is input to the first frequency conversion sub-module of the first E-band frequency conversion channel and the second E-band frequency conversion channel after different frequency multiplication processing of different frequency multipliers, and the second local oscillator signal of the local oscillator signal generator is directly input to the second frequency conversion sub-module of the first E-band frequency conversion channel and the second E-band frequency conversion channel.

[0021] In the embodiment, the first E-band frequency conversion channel and the second E-band frequency conversion channel are designed to have two frequency conversion sub-modules, and the E-band signal is converted to the final intermediate frequency signal through twice frequency conversion, that is, the first frequency conversion sub-module first outputs the first intermediate frequency signal, and then the second frequency conversion sub-module outputs the second intermediate frequency signal as the final output. The twice frequency conversion scheme can reduce link image frequency interference. If a once frequency conversion scheme is used, the intermediate frequency is relatively low, and the input filter cannot suppress the image frequency, so twice frequency conversion is used, the E-band signal is first converted to an intermediate frequency 1, the image frequency 1 can be suppressed by the waveguide filter, and the intermediate frequency 1 is then converted to an intermediate frequency 2, and the image frequency 2 can be suppressed by the intermediate frequency 1 filter. In this way, the entire link image frequency is effectively suppressed. On this basis, the embodiment realizes independent and consistent frequency conversion operations of the two frequency conversion channels, respectively completes the E-band frequency conversion to the intermediate frequency, meets the demand of multi-channel parallel processing, can flexibly adapt to different frequency requirements of the frequency conversion link through the frequency multiplication operation of the local oscillator signal, and at the same time, guarantees the structural symmetry of the two channel frequency conversion channels and improves the consistency between the channels.

[0022] To sum up, the scheme of the embodiment is applicable to the 81-86 GHz frequency band, that is, supports high frequency conversion of the E-band, meets the demand of high frequency radar, communication and the like. The double-channel structure is symmetrical and has strong adaptability, facilitating system expansion and channel balance control. The setting of different frequency multipliers enables different frequency conversion sub-modules to obtain the required local oscillator frequency, improving the overall matching degree. All frequency conversion modules are driven by a unified local oscillator source, have good frequency stability, and are suitable for applications such as multi-channel phased array. On this basis, the double-channel E-band tracking frequency converter completes the conversion of the two E-band signals to the intermediate frequency 70M signal, realizes double-channel tracking frequency conversion, and has high dynamic input range and other performance indicators.

[0023] As a preferred scheme of the embodiment, referring to Figure 2 , the local oscillator signal generator includes a constant temperature crystal oscillator, a plurality of phase-locked loops and a plurality of power dividers, the phase-locked loop x in the figure represents the xth phase-locked loop, and x is a number; The output end of the constant temperature crystal oscillator is connected to the input end of the first phase-locked loop and the input end of the third phase-locked loop, and the output end of the first phase-locked loop is connected to the input end of the second phase-locked loop; The output end of the second phase-locked loop is connected to the input end of the first power divider pd1, and the output end of the first power divider pd1 outputs two output signals of the first local oscillator signal, L01-1 and L01-2 being respectively a first output and a second output of the first local oscillator signal after the first local oscillator signal passes through the first power divider pd1. The output end of the third phase-locked loop is connected to the input end of the second power divider pd2, and the output end of the second power divider pd2 outputs two output signals of the second local oscillator signal, L02-1 and L02-2 being respectively a first output and a second output of the second local oscillator signal after the second local oscillator signal passes through the second power divider pd2.

[0024] The conventional scheme generally generates one local oscillator signal by one local oscillator signal generator, and two local oscillator signal generators are needed in the design of the double-channel to provide the local oscillator signals for the two variable frequency channels, which is high in cost and is not conducive to miniaturization design. Therefore, the embodiment generates two local oscillator signals by one local oscillator signal generator, which can share the phase-locked constant temperature crystal oscillator, power supply and control circuit, reduces the cost and the structure, and is further conducive to high integration.

[0025] In the above scheme, the constant temperature crystal oscillator outputs a high-stability reference frequency signal, which is connected to the input ends of the first phase-locked loop and the third phase-locked loop as the reference sources. The output of the first local oscillator signal is generated by the double phase-locked loop mode, which is good in spurious performance and low in phase noise, and finally generates a local oscillator signal with a step of 0.5KHz, which is output after power division. The second local oscillator signal is generated by the single phase-locked loop mode to generate a point frequency local oscillator signal, which is output after power division. The phase-locked loop can realize precise frequency synthesis of the local oscillator signal, has the characteristics of adjustability and extremely low phase noise. Each power divider divides the local oscillator signal into two paths with equal power, which is used to drive the two-stage variable frequency sub-modules in the double-channel system.

[0026] In addition, the first variable frequency sub-module of the embodiment includes a waveguide filter module, a waveguide-to-coaxial conversion module, a low-noise amplifier, a matching module and a first variable frequency network. In the first E-band variable frequency channel, the second output signal of the first local oscillator signal is input to the first variable frequency network through a first frequency multiplier; In the second E-band variable frequency channel, the first output signal of the first local oscillator signal is input to the first variable frequency network through a second frequency multiplier; The waveguide filter module, the waveguide-to-coaxial conversion module, the low-noise amplifier, the matching module and the first variable frequency network are connected in series.

[0027] In the first frequency conversion sub-module, after receiving the channel input signal, the waveguide filtering module first completes the band-pass selection to filter out the non-target frequency band interference signal and improve the signal purity. Then the wave conversion module efficiently converts the E-band electromagnetic wave signal in the waveguide structure into a form suitable for microstrip circuit transmission. Next, the signal is converted and then enters the low noise amplifier for preliminary amplification while maintaining a low noise coefficient to improve the overall signal-to-noise ratio of the system. The matching module is used to reduce the mismatch between the front stage and the rear stage to improve the link performance. In this embodiment, the matching module is preferably a Π attenuator. Generally speaking, the standing wave at the input end of the frequency conversion network is poor, so the attenuator is used to optimize the standing wave at the input end of the frequency conversion network, enhance the matching performance of the frequency conversion network and the low noise amplifier in the front stage, and improve the link performance. Finally, the signal is sent to the first frequency conversion network, which is mixed with the second output of the first local oscillator signal output by the frequency multiplier to realize the conversion of the signal frequency and provide suitable signals for the subsequent frequency conversion stage.

[0028] Referring to Figure 3 , the first frequency conversion network includes a first mixer and a second Π attenuator, and the matching module uses a first Π attenuator. The output end of the first Π attenuator is connected to the input end of the first mixer, the output end of the first mixer is connected to the input end of the second Π attenuator, and the output end of the second Π attenuator is the output end of the first frequency conversion network.

[0029] The first Π attenuator is located at the front end of the network and can effectively absorb the reflected wave and excessive power of the input signal to protect the mixer from being damaged by the input signal. The second Π attenuator is located at the rear end of the mixer and can perform power shaping and amplitude suppression on the output signal to make the intermediate frequency output power more stable and reliable. The design of this embodiment plays a role in matching, isolation and stable power output, and improves the overall linearity and stability of the system.

[0030] Referring to Figure 5 , the wave conversion module uses a microstrip E-plane probe to couple the electromagnetic field signal to the microstrip through the microstrip E-plane probe.

[0031] As a preferred scheme of this embodiment, the size optimization method of the microstrip E-plane probe is as follows: Through simulation modeling, the length and width of the microstrip E-plane probe and the distance between the microstrip E-plane probe and the waveguide short-circuit surface are used as optimization variables. The optimization target is to simultaneously satisfy that the reflection coefficient is not greater than a preset reflection coefficient threshold and the transmission coefficient is not less than a preset transmission coefficient threshold within the entire working frequency band of 81-86 GHz.

[0032] Specifically, the reflection coefficient threshold is -20 dB, and the transmission coefficient threshold is -0.2 dB.

[0033] After the above optimization, the final waveguide microstrip conversion insertion loss can be less than 0.2dB, and the standing wave is better than 1.2.

[0034] On the other hand, the second E-band frequency conversion channel includes a first filter, a first amplifier, a second frequency conversion network, a second filter, an attenuator and a second amplifier. In the first E-band frequency conversion channel, the second output signal of the second local oscillator signal is input to the second frequency conversion network. In the second E-band frequency conversion channel, the first output signal of the second local oscillator signal is input to the second frequency conversion network. The first filter, the first amplifier, the second frequency conversion network, the second filter, the attenuator and the second amplifier are connected in series.

[0035] The output of the first frequency conversion network first enters the first filter, which is used to filter out irrelevant frequency band interference signals. The signal processed by the first filter enters the first amplifier to meet the frequency conversion processing requirements. The signal output by the first amplifier enters the second frequency conversion network, which also receives the second local oscillator signal from the local oscillator signal generator and converts the received signal to the required frequency signal. Next, the frequency conversion output signal enters the second filter to further filter out local oscillator leakage and spurious components. Then the signal passes through the attenuator for power control to adapt to the power requirements of the subsequent equipment or system. The power-shaped signal is finally output through the second amplifier to ensure that the intermediate frequency signal has sufficient output level and good linearity.

[0036] Referring to Figure 4 A third Π attenuator is provided as a matching module at the front end of the second frequency conversion network, and the second frequency conversion network includes a second mixer and a fourth Π attenuator. The output end of the third Π attenuator is connected to the input end of the second mixer, the output end of the second mixer is connected to the input end of the fourth Π attenuator, and the output end of the fourth Π attenuator is the output end of the second frequency conversion network.

[0037] The second frequency conversion network of the embodiment is consistent with the structure of the first frequency conversion network.

[0038] As a shielding optimization scheme, each element in the first E-band frequency conversion channel and the second E-band frequency conversion channel of the embodiment is arranged in an independent cavity to avoid mutual interference. Referring to Figure 6 One case shows the local arrangement of the first frequency conversion sub-module, in which each module includes signal output and input that are isolated from each other.

[0039] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An E-band frequency conversion channel circuit, characterized in that: It includes a local oscillator signal generator, a first E-band frequency conversion channel, a second E-band frequency conversion channel, a first frequency multiplier and a second frequency multiplier; The local oscillator signal generator outputs a first local oscillator signal and a second local oscillator signal, and the first local oscillator signal and the second local oscillator signal are both divided into two output signals; The first E-band frequency conversion channel and the second E-band frequency conversion channel have the same structure, and both include a first frequency conversion submodule and a second frequency conversion submodule connected in series; The second output signal of the first local oscillator signal is input into the first frequency conversion submodule of the first E-band frequency conversion channel through the first frequency multiplier, and the second output signal of the second local oscillator signal is input into the second frequency conversion submodule of the first E-band frequency conversion channel; The first output signal of the first local oscillator signal is input to the first frequency conversion submodule of the second E-band frequency conversion channel through the second frequency multiplier, and the first output signal of the second local oscillator signal is input to the second frequency conversion submodule of the second E-band frequency conversion channel.

2. The E-band frequency conversion channel circuit according to claim 1, characterized in that: The local oscillator signal generator includes a constant temperature crystal oscillator, multiple phase-locked loops and multiple power dividers; The output end of the constant temperature crystal oscillator is connected to the input end of the first phase-locked loop and the input end of the third phase-locked loop, and the output end of the first phase-locked loop is connected to the input end of the second phase-locked loop; The output end of the second phase-locked loop is connected to the input end of the first power divider, and the output end of the first power divider outputs two outputs of the first local oscillator signal; The output end of the third phase-locked loop is connected to the input end of the second power divider, and the output end of the second power divider outputs two paths of the second local oscillation signal.

3. The E-band frequency conversion channel circuit according to claim 1, characterized in that: The first frequency conversion submodule includes a waveguide filtering module, a waveguide conversion module, a low noise amplifier, a matching module and a first frequency conversion network; In the first E-band frequency conversion channel, the second output signal of the first local oscillator signal is input into the first frequency conversion network through the first frequency multiplier; In the second E-band frequency conversion channel, the first output signal of the first local oscillator signal is input into the first frequency conversion network through the second frequency multiplier; The waveguide filter module, the waveguide conversion module, the low noise amplifier, the matching module and the first frequency conversion network are connected in series in sequence.

4. The E-band frequency conversion channel circuit according to claim 3, characterized in that: The first frequency conversion network includes a first mixer and a second π-type attenuator, and the matching module adopts the first π-type attenuator; The output end of the first Π-type attenuator is connected to the input end of the first mixer, the output end of the first mixer is connected to the input end of the second Π-type attenuator, and the output end of the second Π-type attenuator is the output end of the first frequency conversion network.

5. The E-band frequency conversion channel circuit according to claim 3, characterized in that: The wavelet conversion module adopts a microstrip E-plane probe, and couples the electromagnetic field signal into the microstrip through the microstrip E-plane probe.

6. The E-band frequency conversion channel circuit according to claim 5, characterized in that: The size optimization method of the microstrip E-plane probe is: Through simulation modeling, the length and width of the microstrip E-plane probe and the distance between the microstrip E-plane probe and the waveguide short-circuit surface are used as optimization variables; The optimization goal is to simultaneously satisfy the following requirements in the entire operating frequency band of 81–86 GHz: the reflection coefficient is no greater than the preset reflection coefficient threshold, and the transmission coefficient is no less than the preset transmission coefficient threshold.

7. The E-band frequency conversion channel circuit according to claim 6, characterized in that: The reflection coefficient threshold is -20 dB, and the transmission coefficient threshold is -0.2 dB.

8. The E-band frequency conversion channel circuit according to claim 1, characterized in that: The second E-band frequency conversion channel includes a first filter, a first amplifier, a second frequency conversion network, a second filter, an attenuator, and a second amplifier; In the first E-band frequency conversion channel, the second output signal of the second local oscillator signal is input into the second frequency conversion network; In the second E-band frequency conversion channel, the first output signal of the second local oscillator signal is input into the second frequency conversion network; The first filter, the first amplifier, the second frequency conversion network, the second filter, the attenuator and the second amplifier are connected in series in sequence.

9. The E-band frequency conversion channel circuit according to claim 8, characterized in that: A third Π-type attenuator is provided at the front end of the second frequency conversion network as a matching module, wherein the second frequency conversion network includes a second mixer and a fourth Π-type attenuator; The output end of the third Π-type attenuator is connected to the input end of the second mixer, the output end of the second mixer is connected to the input end of the fourth Π-type attenuator, and the output end of the fourth Π-type attenuator is the output end of the second frequency conversion network.

10. The E-band frequency conversion channel circuit according to claim 1, characterized in that: Each element in the first E-band frequency conversion channel and the second E-band frequency conversion channel is respectively arranged in an independent cavity.

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