Implementation of a two-stage digital AGC for spectrum analyzer

Author

Zheng, Xing ; Wang, Zhi Gang ; Huang, Yue Cheng

Author_Institution

Sch. of Autom. Eng., Univ. of Electron. Sci. & Technol. of China, Chengdu, China

fYear

2011

fDate

14-16 Dec. 2011

Firstpage

37

Lastpage

40

Abstract

A new digital Automatic gain control (AGC) circuit with two-stage gain adjustment is proposed in this paper. This AGC circuit is designed as part of an intermediate frequency (IF) processing circuit in the spectrum analyzer. The first stage controls the gain in 20 dB Steps and improves the measurement range of the RMS detector, while the second stage controls the gain in 3 dB Steps and gets a precise output signal. The gain of the two stages of amplifier is coordinated by a gain control logical module. Simulations for the control algorithm are implemented; the results show this control algorithm has some advantages in aspects of rapidity and astringency. Due to the large available gain provided by two-stage gain adjustment, a large controllable input range can be obtained. Experimental results show that the detectable range of this AGC circuit is -105 dBm to 18 dBm at a 60 MHz IF frequency.

Keywords

automatic gain control; spectral analysers; IF frequency; RMS detector; digital automatic gain control circuit; frequency 60 MHz; gain 20 dB; gain 3 dB; gain control logical module; intermediate frequency processing circuit; spectrum analyzer; two-stage digital AGC circuit; two-stage gain adjustment; Accuracy; Automatic generation control; Detectors; Electronics packaging; Filtering theory; Gain; Gain control; automatic gain control (AGC); intermediate frequency (IF); spectrum analyzer; two-stage gain adjustment;

fLanguage

English

Publisher

ieee

Conference_Titel

Applied Superconductivity and Electromagnetic Devices (ASEMD), 2011 International Conference on

Conference_Location

Sydney, NSW

Print_ISBN

978-1-4244-7852-1

Type

conf

DOI

10.1109/ASEMD.2011.6145062

Filename

6145062