Third-Order Elliptic Lowpass Filter for Multi-Standard Baseband Chain Using Highly Linear Digitally Programmable OTA

International Conference on Applied Electronic and Engineering 2017

无线电电子学;工业技术

Elamien, Mohamed B.^1 ; Mahmoud, Soliman A.^1

Department of Electrical and Computer Engineering, University of Sharjah, United Arab Emirates^1

关键词: Adaptive biasing;    Current division network;    Cutoff frequency tuning;    Double differential;    Elliptic lowpass filter;    Linearization technique;    Source degeneration;    Third order harmonics;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/341/1/012005/pdf
DOI  :  10.1088/1757-899X/341/1/012005

学科分类：工业工程学

来源: IOP

【 摘 要 】

In this paper, a third-order elliptic lowpass filter is designed using highly linear digital programmable balanced OTA. The filter exhibits a cutoff frequency tuning range from 2.2 MHz to 7.1 MHz, thus, it covers W-CDMA, UMTS, and DVB-H standards. The programmability concept in the filter is achieved by using digitally programmable operational transconductors amplifier (DPOTA). The DPOTA employs three linearization techniques which are the source degeneration, double differential pair and the adaptive biasing. Two current division networks (CDNs) are used to control the value of the transconductance. For the DPOTA, the third-order harmonic distortion (HD3) remains below -65 dB up to 0.4 V differential input voltage at 1.2 V supply voltage. The DPOTA and the filter are designed and simulated in 90 nm CMOS technology with LTspice simulator.