Low-noise high-gain waveguide radio frequency front end

Abstract

The utility model relates to a low-noise high-gain waveguide radio frequency front end, which relates to the technical field of radar receiving front ends and comprises a waveguide port, a first isolator, an amplitude limiter, a first low-noise amplifier, a temperature compensator, a filter, an attenuator, a second low-noise amplifier, a second isolator and an N-type connector which are connected in sequence. Wherein the insertion loss of the amplitude limiter is 0.15 dB; the noise coefficient of the first low noise amplifier is 0.78 dB; and the noise coefficient of the second low noise amplifier is 1.2 dB. By controlling the loss of a passive device at the front end of the low-noise amplifier and the noise coefficient of the low-noise amplifier, the full-band noise coefficient can be less than 1.5 dB, namely the requirement of low noise is met, so that the receiving sensitivity of a radar receiving complete machine system is improved.

Description

Technical Field

[0001] This application relates to the field of radar receiving front-end technology, and particularly to a low-noise and high-gain waveguide radio frequency front-end. Background Art

[0002] There are various types and functions of existing radar receiving front-end modules, and generally they are designed specifically for the whole radar. The receiving front-end module mainly realizes the function of limiting low-noise amplification, amplifying the weak radio frequency signals received by the radar antenna, and supplying them to the signal processing of the subsequent frequency conversion channel or the radio frequency direct sampling method. Therefore, the design of the front-end module plays a crucial role in the sensitivity of the entire receiver. If the noise is high, it will affect the sensitivity of the entire receiver. This application aims at the receiving front-end index requirements proposed for the whole machine system, that is, the ultra-low noise and high-gain design index requirements within the working frequency band, and designs a low-noise and high-gain waveguide radio frequency front-end. Utility Model Content

[0003] A low-noise and high-gain waveguide radio frequency front-end provided by this application adopts the following technical solutions:

[0004] A low-noise and high-gain waveguide radio frequency front-end includes a waveguide port, a first isolator, a limiter, a first low-noise amplifier, a temperature compensator, a filter, an attenuator, a second low-noise amplifier, a second isolator, and an N-type connector connected in sequence; wherein, the insertion loss of the limiter is 0.15 dB; the noise figure of the first low-noise amplifier is 0.78 dB; the noise figure of the second low-noise amplifier is 1.2 dB.

[0005] In one embodiment, the input signal is input from the waveguide port, and the frequency range of the input signal is 5.4 GHz - 5.9 GHz.

[0006] In one embodiment, the limiter can withstand a continuous wave power of 10 W, and satisfies that the continuous wave power is greater than 1 W and the pulse power is greater than 10 W.

[0007] In one embodiment, the standing wave of the waveguide port is less than 1.2.

[0008] A low-noise and high-gain waveguide radio frequency front-end provided by an embodiment of the present disclosure can achieve the following technical effects:

[0009] By controlling the loss of the passive devices in front of the low-noise amplifier and the noise figure of the low-noise amplifier, the noise figure of the entire frequency band can be less than 1.5 dB, that is, the requirement of low noise is met, so as to improve the receiving sensitivity of the entire radar receiving system.

[0010] The above general description and the following description are only exemplary and explanatory, and are not used to limit this application. Brief Description of the Drawings

[0011] Figure 1 It is a schematic structural diagram of a low-noise and high-gain waveguide radio frequency front end provided by an embodiment of the present application.

[0012] Description of the reference numerals: 1, waveguide port; 2, first isolator; 3, limiter; 4, first low-noise amplifier; 5, temperature compensator; 6, filter; 7, attenuator; 8, second low-noise amplifier; 9, second isolator; 10, N-type connector. Detailed Description of the Embodiment

[0013] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0014] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, in the description of the present utility model, "a plurality of" means two or more unless otherwise specifically defined.

[0015] The following is further described in detail with reference to the attached Figure 1 This application is further described in detail.

[0016] An embodiment of the present application discloses a low-noise and high-gain waveguide radio frequency front end, including a waveguide port 1, a first isolator 2, a limiter 3, a first low-noise amplifier 4, a temperature compensator 5, a filter 6, an attenuator 7, a second low-noise amplifier 8, a second isolator 9 and an N-type connector 10 connected in sequence; wherein, the insertion loss of the limiter 3 is 0.15 dB; the noise figure of the first low-noise amplifier is 0.78 dB; the noise figure of the second low-noise amplifier is 1.2 dB.

[0017] By controlling the loss of the passive devices at the front end of the low-noise amplifier and the noise figure of the low-noise amplifier, the noise figure of the entire frequency band can be less than 1.5 dB, that is, the requirement of low noise is met, thereby improving the receiving sensitivity of the radar receiving system as a whole.

[0018] The C-band RF signal enters the module through waveguide port 1, and after passing through the isolator, it undergoes limiting low-noise amplification processing. After filtering out clutter through filter 6 and then amplifying, the signal is finally output from the module through N-type connector 10.

[0019] Waveguide port 1 is a BJ-58 type general waveguide, which is docked with the waveguide interface at the antenna end to achieve low loss and small reflection of RF signal transmission. The first isolator 2 and the second isolator 9 ensure that the port standing wave is as low as possible, further avoiding signal reflection and reducing the RF performance of the front-end module. The limiting low-noise amplifier circuit composed of the limiter 3 and the first low-noise amplifier 4 not only effectively attenuates high-power signals when input from the antenna to protect the subsequent circuits from damage, but also performs low-noise amplification processing when weak radar signals are input. The filtering and amplification circuit composed of the temperature compensator 5, the filter 6, the attenuator 7 and the second low-noise amplifier 8 filters out out-of-band clutter signals of the RF signal and amplifies the RF signal to meet the gain index requirements of the module.

[0020] In one embodiment, the above-mentioned limiting low-noise amplifier circuit can provide a gain of 29 dB for small-power signals.

[0021] In one embodiment, the above-mentioned filtering and amplification circuit filters the RF signal and amplifies the RF signal again, providing a gain of 25 dB.

[0022] In one embodiment, the input signal is input from waveguide port 1, and the frequency range of the input signal is 5.4 GHz - 5.9 GHz.

[0023] In one embodiment, the gain of this application meets 43 ± 1.5 dB.

[0024] In one embodiment, the limiter 3 can withstand a continuous wave power of 10 W and meets the requirements that the continuous wave power is greater than 1 W and the pulse power is greater than 10 W.

[0025] In one embodiment, the port standing wave of waveguide port 1 is less than 1.2, and the insertion loss within the passband is 0.12 dB. The first isolator 2 and the second isolator 9 ensure that the port standing waves at the input and output of the module are within 1.2, avoiding RF signal reflection and reducing the risk of deterioration of the overall machine cascade use index.

[0026] The above are all preferred embodiments of this application. It does not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A low-noise and high-gain waveguide RF front-end, characterized in that, It includes a waveguide port, a first isolator, a limiter, a first low-noise amplifier, a temperature compensator, a filter, an attenuator, a second low-noise amplifier, a second isolator and an N-type connector connected in sequence; wherein, the insertion loss of the limiter is 0.15 dB; the noise figure of the first low-noise amplifier is 0.78 dB; the noise figure of the second low-noise amplifier is 1.2 dB.

2. The low-noise and high-gain waveguide radio frequency front end according to claim 1, wherein: The input signal is input from the waveguide port, and the frequency range of the input signal is 5.4 GHz - 5.9 GHz.

3. The low-noise high-gain waveguide RF front-end according to claim 1, characterized in that: The limiter can withstand a continuous wave power of 10 W and meets the requirements that the continuous wave power is greater than 1 W and the pulse power is greater than 10 W.

4. The low-noise high-gain waveguide RF front end according to claim 1, wherein: The standing wave of the waveguide port is less than 1.2.

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