A New Gaussian Band-IF Receiver

Abstract

A novel Gaussian passband intermediate frequency receiver provided by the invention consists of two stages before and after, including a low noise amplifier, an attenuation matching network, a front-stage Gaussian filter, a post-stage Gaussian filter, a numerically controlled attenuator, a wideband gain amplifier, a wideband mixing The low-noise amplifier is connected with the attenuation matching network, the front-stage Gaussian filter, the numerically controlled attenuator, the broadband gain amplifier, and the broadband mixer to form the first-stage process, and is then matched with the broadband gain amplifier, attenuation matching The network, the post-stage Gaussian filter, the numerical control attenuator, the broadband gain amplifier, and the final-stage driver amplifier are connected in sequence to form the second-stage process. The invention is based on a Gaussian filter, and the filter has the characteristics of small in-band group delay fluctuation and high phase linearity, so as to reduce the in-band noise power of the receiver signal and eliminate the impact and ringing phenomenon of the modulated pulse signal. the goal of. At the same time, the broadband design is adopted to increase the information amount of the available signal to improve the detection accuracy of the receiver system.

Description

technical field [0001] The invention relates to a novel Gaussian pass band intermediate frequency receiver. Background technique [0002] During the working process of the semi-active radar seeker, due to the impure spectrum of the irradiation signal, the phase noise in the signal, the phase noise sideband of the local oscillator modulated into the signal channel and the clutter signal are easy to enter the speed gate, causing the receiver system to fail. Minimal target signal detected. Therefore, how to reduce the noise power, phase noise sideband and clutter technology in the signal channel of the receiver system, that is, anti-leakage and clutter technology, is one of the technical difficulties in the development of semi-active radar seekers. As for how to improve the visibility index of the receiver system, the usual method is to compress the speed gate or the bandwidth of the signal channel to reduce the phase noise power of the radiation leakage signal and clutter sig...

AI Technical Summary

Problems solved by technology

It can be seen from the figure that the group delay fluctuates greatly at the sideband of the passband, and the signal distortion is serious, which will cause the deterioration of the phase noise in the signal channel and increase the noise power

At the same time, due to the severe impulse response and step response characteristics of the narrowband filter, it will cause serious shock and ringing at the front and back ends of the modulated pulse, resulting in the loss of signal information within the pulse width

Therefore, although the IF receiver designed with a narrowband filter can effectively reduce the noise power of the radiation leakage signal entering the signal channel, the receiver itself will increase the noise power in the channel due to the characteristics of the narrowband filter, and the visibility under system leakage, etc. Metrics won't improve much

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