A X-band CMOS power amplifier with on-chip transmission line transformers

A X-band CMOS power amplifier (PA) has been fabricated using a 0.18-μm CMOS technology. On-chip transmission line transformers are used as matching elements for output, input, and inter-stage matching. The power amplifier provides the saturated output power of 23.5 dBm and 1-dB gain-compressed output power (P
1dB
) is 21 dBm at 8.5 GHz with 3.3 V supply. The gain is 29 dB and power-added-efficiency (PAE) is 19 % at 8.5 GHz. Among the reported X/Ku band CMOS power amplifiers, this amplifier has the largest output power.