Anti-blocking interference automatic gain control circuit and control method

Abstract

The invention provides an anti-blocking interference automatic gain control circuit and a control method. The control circuit is suitable for co-site adjacent band interference suppression and space adjacent channel interference suppression in a complex electromagnetic environment. The control circuit is composed of a tuning amplification module, a fixed gain low noise amplification module, a radio frequency agility module, a clock generation module and an automatic gain control module, and an automatic gain control method is realized in the automatic gain control module. The tuning amplification module is composed of two stages of tuning filters and an internally-clamped one-stage low noise amplifier, the tuning filters ensure that co-location adjacent band interference does not affect the linearity of the low noise amplifier, the low noise amplifier ensures that the noise system of the whole machine is as low as possible, and the combination of the tuning filters and the low noise amplifier can ensure the sensitivity of a receiving system under high-power co-location adjacent band interference outside 10%. The automatic gain control method adopts a feed-forward and feed-backward combined gain control mode, and has the characteristics of high gain adjustment speed, high gain adjustment precision and strong space adjacent channel suppression capability.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to an automatic gain control circuit and control method for anti-blocking interference. Background technique [0002] On the current combat platform that integrates many radio frequency systems such as communication, radar, electronic warfare, and reconnaissance, various high-power transmitting equipment and high-sensitivity receiving equipment need to work on the same platform. The high-sensitivity receiving equipment is easily affected by the high-power transmitting equipment of the co-location platform, the nonlinear effect of the high-power power amplifier, the complex coupling relationship between the transmitting and receiving antennas, and the frequency band range of the receiving equipment can form an interference voltage of several millivolts to tens of volts signal, the front-end circuit is extremely susceptible to blockage. The blocking interference of the co-loca...

AI Technical Summary

Problems solved by technology

[0003] High-sensitivity receiving equipment is also vulnerable to the interference of spatial adjacent band blocking. For example, in the ultrashort wave 30-512MHz frequency band, the channel is limited, and many frequency units working at the same time can easily lead to channel collision.

Space adjacent band interference is non-cooperative, and the strength relationship between the interference signal and the useful signal, frequency deviation, etc. are unpredictable. The existence of the interference signal will compress the amplification factor of the useful signal, resulting in a decrease in the input signal-to-noise ratio of the demodulation terminal of the receiving device. Unable to demodulate in severe cases

[0004] The invention patent with the application number CN201710851619 discloses an adaptive control circuit and control method for an adaptive interference cancellation device, and the invention patent with the application number CN201710846705 discloses a co-site interference cancellation device for multiple transceivers , but the interference handled by the above circuit or method is cooperative co-location platform interference, which cannot deal with non-cooperative blocking interference in adjacent space

[0005] The invention patent with application number CN201810355890.6 discloses a method, device and equipment for improving the blocking index of equipment, and the invention patent with application number CN202110352370.1 discloses a broadband receiving device with anti-blocking interference, and the application number is CN201680066928. The invention patent of 7 discloses a system and method for adjusting the size of the blocking margin through automatic gain control, but the interference processed by the above method or device is non-cooperative spatial blocking interference, which cannot deal with cooperative blocking interference The technical problem caused by the saturation of the front-end circuit

[0006] The invention patent with the application number CN201711065583.6 discloses a device to improve the anti-interference performance, but the input power of the frequency-selective filter amplifier module at the front end of the device is limited (about -20dBm), and it cannot handle the self-interference of the high-power co-location platform (up to 22dBm)

[0007] In summary, none of the above inventions is applicable to interference suppression scenarios where cooperative blocking interference and non-cooperative blocking interference coexist

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