A wideband CMOS VGA with dB-linear gain based on active feedback and negative capacitance

Maryam Dongi | Mohsen Jalali

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=43538
Date :  2017/04/17
Publish in :    بيست و پنجمين کنفرانس مهندسي برق ايران (ICEE 2017)
DOI :  https://doi.org/10.1109/iraniancee.2017.7985090
Link :  http://www.conferenceyab.ir/13708/conferences/engineering/electronics/twenty-fifth-iranian-conference-on-electrical-engineering-icee2017
Keywords :Wideband, CMOS, Feedback, Negative, Capacitance

Abstract :

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In this paper, a low power and wideband variable gain amplifer (VGA) with dB-linear gain control characteristic is presented. This design contains three stages of differential amplifer. To achieve accurate dB-linear characteristic and broadband response, sub-threshold loads and negative capacitance are employed, respectively. In addition, active feedback structure is utilized to further extend the bandwidth. Implemented in an 180nm CMOS process, simulation results indicate that the proposed VGA achieves a gain control range of 34 dB, which -25 dB i dB-linear with ±l dB gain error and 1.1 GHz bandwidth. The power consumption is only 0.7 mW from a 1.8 V supply.

http://www.conferenceyab.ir/13708/conferences/engineering/electronics/twenty-fifth-iranian-conference-on-electrical-engineering-icee2017