ULTRA-LOW DE POWER GAAS HBT S-BAND AND C-BAND LOW-NOISE AMPLIFIERS FOR PORTABLE WIRELESS APPLICATIONS

We report on a 2.1 mW low de power GaAs HBT LNA with 2.0 dB noise figu re and 8.9 dB gain at 2 GHz. This amplifier achieves a Gain/NF . P-dc ratio figure of merit of 2.10 (1/mW) which is the highest reported at S-band, Under low de power bias of 2 V and 0.46 mA (0.92 mW), the ampl ifier achieves 5.2 dB gain, 3.01 dB noise figure and a Gain/P-dc figur e of merit of 5.65 (dB/mW) which is also the highest reported in this frequency band, In addition, a 2-stage self-biased C-band LNA which ac hieves a minimum noise figure of 2.4 dB at 5 GHz, 16.2 dB gain, with o nly 72 mW of de power was also demonstrated. This is believed to be th e lowest noise figure performance so far reported for an HBT amplifier above 3 GHz. Both HBT LNA's are fabricated using a relaxed 3 mu m emi tter width low cost GaAs production foundry process, The high performa nce obtained from HBT's at very low de bias makes them attractive for portable wireless applications in the Industrial-Scientific-Medical (I SM) frequency bands.