A 5/6 GHz Compact, Dual-Band, and Highly Linear Wi-Fi 6E SiGe HBT Power Amplifier Using Q-Modulated Switched Capacitor Interstage Matching Network and Optimized Output Stage

This work presents a compact, highly linear SiGe HBT power amplifier (PA) for Wi-Fi 6E application. To cover the entire 5/6 GHz band, a Q-modulated switched capacitor interstage matching network, a broadband transformer balun, and an optimized output stage layout are co-designed. With these circuit design techniques, the proposed PA maintains similar small/large signal performance at 5/6 GHz band. The two-stage PA is fabricated in 0.35-μm SiGe HBT BiCMOS technology, with its chip DIE size of 0.73 mm2. Measured small signal gains are 27.0/27.0 dB at 5/6 GHz band, with gain variation less than 0.12 dB at any 80 MHz channel bandwidth (BW). Linear output power (PAVG) is x/y/z/x/y/z dBm (EVM=-35 dB) at 5250/5570/5850/6025/6585/6985 MHz under an 802.11ac MCS9 VHT80 signal. The SiGe PA also supports 802.11ax MCS11 VHT160 signal with PAVG of x dBm, at EVM = -38 dB.