Electronic Science and Technology ›› 2019, Vol. 32 ›› Issue (12): 1-5.doi: 10.16180/j.cnki.issn1007-7820.2019.12.001

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A Power Feedback Circuit of IF Signal With Dual-Coupled and Dual-Mixed

ZHENG Renping,YANG Qinghui,ZHANG Huaiwu   

  1. State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China
  • Received:2018-12-06 Online:2019-12-15 Published:2019-12-24
  • Supported by:
    National Natural Science Foundation of China(61021061);National Natural Science Foundation of China(51272036);National Natural Science Foundation of China(51472046);National Natural Science Foundation of China(51002021);National Natural Science Foundation of China(61131005);International Cooperation Foundation of China(2012DFR10730);International Cooperation Foundation of China(2013HH0003)


In ALC system, there is a major limitation of commonly used power feedback circuits: the amplitude modulation dynamic range is restricted by the level detector and associated circuitry, which is typically much lower than the power variable range of the linear modulator. This paper introduced a dual-coupled and dual-mixed IF signal power feedback circuit, so that the detector could feedback and adjust the power amplitude of the RF output signal only by detecting the power of the fixed IF signal. The test showed that when the RF input signal of the circuit changed at 24 GHz, the obtained IF signal was fixed, which was equal to 54 MHz of the crystal signal. And when the attenuation of the linear modulator changed from 0 to 31.5 dB, the IF signal power had a good linear relationship with the RF output signal power, which met the expected design requirements.

Key words: Automatic Level Control, power feedback, detector, dual-coupled, dual-mixed, fixed intermediate frequency

CLC Number: 

  • TN702