GaAs & Si MMIC Building Blocks: a moot point revisited

The emergence of large volume markets for commercial space and ground telecommunication systems is beginning to reignite the smouldering Si-GaAs controversy mainly limited so far to high speed digital applications. The main difference now is that GaAs IC processes and especially N-off mixed a/d processes like PMI s PR07AD, have matured into commercially available products. More specifically they yield a better cost-performance trade-off than their Si counterparts down to L-band when low noise and low DC power is the issue. Basic GaAs analogue-digital building blocks like LNAs, active mixers, VCOs, PLLs and power modules are available today, either as standard ICs or as standard cells for ASIC design. Very low DC power Fully and high packing density monolithic downconverters including an RF LNA, mixer and a VCO can thus be designed with 4.5 dB NF and 20 dB associated gain at 1.9 GHz and a drain current as low as 4 mA at Vdd - 3 V for a chip area as small as 0.5 mm².