Electronic Science and Technology ›› 2021, Vol. 34 ›› Issue (2): 57-61.doi: 10.16180/j.cnki.issn1007-7820.2021.02.010

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Design of a Broadband Large Dynamic AGC Circuit

MAO Yunshan,WEI Xubo   

  1. School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China
  • Received:2019-11-07 Online:2021-02-15 Published:2021-01-22
  • Supported by:
    National Natural Science Foundation of China(61471086)


A high-frequency broadband large dynamic AGC circuit is designed for the high frequency, wide frequency band and large dynamics of automatic gain control circuits. In this paper, the problem of inaccurate power detection caused by the bottoming of the wideband circuit is solved by adopting the narrow banding method of the AGC coupling signal, and the large dynamic of the AGC circuit is realized by the cascade control of the two-stage voltage-controlled gain amplifier. The input and output amplification filter circuit is added to improve signal purity. According to the design, the measured AGC circuit has a dynamic range of 100 dB when the signal frequency is 2 GHz and the signal bandwidth is 200 MHz, which improves the applicable frequency and bandwidth when compared with the conventional AGC circuit.

Key words: AGC, high-frequency, broadband, large dynamic, power detection, VGA

CLC Number: 

  • TN850.3