| With the advantages such as extremely wide bandwidth, the unlicensed band around 60GHz has permitted multi-Gbps transmission speed, which appeases people’s demand for high speed in the short-range wireless communication. However, the design of milimeter-wave fully integrated transceiver chip in CMOS, especially the power amplifier(PA) module, is very difficult due to the medium resistivity substrate and low breakdown voltage. Advances in power combiner and neutralized common-source amplifier has enhanced PA’s output power and gain. However, linearity and back-off power added efficiency(PAE) of CMOS PAs are still limited.In this desgin, based on the transformer and neutralized common-source amplifier pair, multi-gated transistors(MGTR) structure is implemented. Analysis of this structure shows MGTR is able to enhance both the linearity and back-off PAE without consuming extra DC power.To demonstrate the feasibility of this approach, a two stage 60-GHz band transformer-coupled power amplifiers is realized in 65-nm bulk CMOS process, and the chip area is 0.49mm2. When supply voltage is set to Ⅳ, the DC power dissipation is 24mW. At 54GHz, the saturated output power and the output 1dB compression point is 10.5dBm and 7.62dBm, respectively. Compared with other state-of-art PAs with the same DC power, the achieved saturation PAE and 1dB PAE(23.3% and 16.98%) are the highest. Moreover, from 51GHz to 56GHz, the 1dB PAE is more than 8%. |
