802.11a Compliant Spatial Diversity Receiver IC in BiCMOS

摘要

This paper presents an integrated 802.11a compliant receiver integrated circuit (IC), which is capable of processing four antenna signals using RF multiple-input multiple-output (RF-MIMO) schemes. Following four low-noise amplifiers, the weighting is performed using Cartesian vector modulators, whose output signals are combined and down-converted. The baseband filters, variable gain amplifiers (VGAs), a quadrature voltage-controlled oscillator, and digital interfaces are integrated. Experimental results demonstrate the performance of the individual components, as well as the RF-MIMO capabilities of the whole chip. The IC achieves a receiver noise figure of 3.6 dB, a phase noise of -113 dBc/Hz at 1-MHz offset, and an equivalent Cartesian weighting precision of 6 × 6 bit. An RF input signal of up to -35.3 dBm (1-dB compression) can be processed, while the maximum RF path gain amounts to 28.6 dB. The baseband VGA provides further 9-61-dB gain in 64 steps.