A 2.4GHz CMOS front-end having improved antenna isolation for diversity

Abstract

A front-end having improved antenna isolation for diversity in a 0.18ȝm CMOS technology is presented. In order to reduce the external components, two switches for antenna diversity are integrated in front of LNA on the chip. A stacked inductor technique is adopted to reduce the chip area. The simulation and measurement results show that the front-end (LNA, Mixer) can achieve a voltage gain of 33.5dB, a noise figure (NF) of 3.8dB and 23dB of the isolation between antennas is achieved while consuming 3.9mW with a 1.8V power supply. The NF includes the loss of BALUN, BPF and switches.