On the Suitability of Discrete-Time Receivers for Software-Defined Radio

—CMOS radio receiver architectures, based on radio frequency (RF) sampling followed by discrete-time (D-T) signal processing via switched-capacitor circuits, have recently been proposed for dedicated radio standards. This paper explores the suitability of such D-T receivers for highly flexible softwaredefined radio (SDR) receivers. Via symbolic analysis and simulations we analyze the properties of D-T receivers, and show that at least three challenges exist to make a D-T receiver work for SDR: 1) the sampling clock frequency is related to the radio frequency, complicating baseband filter design; 2) a frequency-dependent phase shift is introduced by pseudoquadrature and pseudo-differential sampling; 3) the conversion gain of a charge sampling front-end is strongly frequencydependent. Compared to a mixer based radio receiver, extra costs are needed to solve these problems.

• Type: Conference
• Year: 2007
• Where: ISCAS
• Authors: Zhiyu Ru, Eric A. M. Klumperink, Bram Nauta
• Keywords: D-t Receiver, ISCAS 2007, Radio Frequency, Radio Receiver