Design and Application of a Series and Parallel-summation Logarithmic Video Amplifier

Abstract

Starting with the concept of logarithmic video amplifier, this paper mainly derives the transfer functions of different logarithmic video amplifiers. The practical application of logarithmic video amplifier in the radar warning receiver is designed, and three pieces of conclusion about logarithmic video amplifier in RWR have been reached. Firstly, logarithmic transformation is completed for obtaining the azimuth information. Secondly, compressing the dynamic range is realized so that to the subsequent circuits signal processing becomes easier. Thirdly, the signal is amplified for improving the sensitivity of the receiver. A three-parallel-summation and single-series logarithmic video amplifier is used in a RWR so its direction finding precision is up to 8°, its dynamic range is up to 140dB, its sensitivity is up to -80dBm and its technique is in a higher level.