A Multimode 5–6 GHz sige BiCMOS PA design powers emerging wireless LAN radio standards

A multimode 5-6 GHz SiGe BiCMOS PA IC that powers the emerging Wireless LAN applications is presented. The design can be realized in a 1.35 × 0.7 active area as a standalone power amplifier (PA) or the transmit (Tx) chain of a Front-end IC. The design features multiple modes with low DEVM supporting 1024 QAM data rates and >20 dB accurate power controls. The linearity is well scaled with supply voltage from 2.8V to 5.5 V and insensitive to modulation bandwidths and duty cycles. With a 5 V supply, the PA has 32 dB gain and meets -41 dB DEVM for 1024 QAM, up to 20 dBm Pout and -35 dB DEVM for 256 QAM 802.11ac up to 21 dBm Pout. The design has also support a low power mode having 3 dB less linear power, with reduced current. With DPD, the low linearity mode can achieve similar linear power as the high linearity mode with 40 mA current reduction. The diverse features of the PA IC simplify front-end circuit designs of emerging high throughput radio standards.