Experimental performance comparison of six-port and conventional zero-IF/low-IF receivers for software defined radio

Abstract

This paper presents an experimental performance comparison among three RF architectures that are very suitable for Software De¯ned Radio (SDR) implementation: zero-IF, low-IF, and six-port network. A six-port receiver and a dual zero-IF/low-IF receiver have been developed for this purpose. Six-port receiver is a very promising and fexible RF architecture for the low-cost implementation of integrated microwave and millimeter-wave systems. Competitive advantages such as ultra-broadband behavior, low-cost, reconfigurability, and low power consumption, point to the six-port architecture as a good candidate to implement a SDR. However, two issues on broadband six-port receivers require intensive research: dynamic range extension, and miniaturization. In this paper, two solutions are proposed to solve these problems: the use of biased detector diodes for dynamic range extension, and the use of low temperature cofired ceramic (LTCC) technology for six-port reduction. The measurement results indicate that the six-port receiver shows high potential benefits and advantages compared to conventional zero-IF and low-IF receivers. In addition, the capability of the six-port architecture to operate as both zero-IF and low-IF receivers has been experimentally demonstrated for the first time.