2-18GHz large-dynamic detection logarithm video amplifier

Abstract

The invention discloses a 2-18GHz large-dynamic detection logarithm video amplifier. The device comprises a radio frequency front end, a logarithm amplifier circuit, and a synthesis circuit; the radiofrequency front end comprises an ultra-broadband micro-band power divider, a broadband low-noise amplifier and a wave detector; the radio frequency front end equally divides the input radio frequencysignal into two paths, one path enters a low-noise amplifier link to be amplified, and performs the detection output, the other path directly enters the wave detector and performs the detection output; the logarithm amplifier circuit outputs and synthesizes two paths of detection video signals output by the radio frequency front end after performing the logarithm amplification on the same; a temperature compensation circuit is used for performing temperature compensation on the zero drift under the logarithm temperature change; the synthesis circuit comprises an addition circuit and an amplification circuit; the addition circuit performs adding and synthesis on the signal after the logarithm amplification and the temperature compensation voltage, and the amplification circuit amplifies the synthesized signal to obtain a final video output signal. The 2-18GHz large-dynamic detection logarithm video amplifier disclosed by the invention has the advantages of being large in radio frequency broadband range, high in sensitivity, and good in working temperature adaptation.

Description

technical field [0001] The invention relates to the technical field of broadband radio frequency signal power measurement, in particular to a 2-18GHz large dynamic detection logarithmic video amplifier. Background technique [0002] Detecting Logarithmic Video Amplifiers (DLVA) In modern receiving systems, the need to handle high density pulses with narrow pulses and large amplitudes makes the use of logarithmic amplifiers possible. Simply put, this kind of amplifier condenses the input signal with a large dynamic range into a sufficiently small and easy-to-handle signal through the logarithmic conversion function. The result of the logarithmic conversion is to make the output voltage of the logarithmic amplifier proportional to the power of the input signal. In most cases, a logarithmic amplifier is used as an amplitude detector, and because its output voltage is proportional to the input signal power, the amplitude information displayed by the amplifier is often more usef...

AI Technical Summary

Problems solved by technology

Constrained by the gain-bandwidth product of the video section, this large gain will affect the amplifier rise time and recovery time

In the existing products, there are disadvantages: 1) The working bandwidth is narrow, generally 2-8GHz or 6-18GHz; 2) The linear dynamic range is small, generally about 60dB; 3) The temperature stability is poor, and its zero point level is at -40℃~+85℃ temperature changes greatly

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