A 28/60GHz Dual-Band Power Amplifier

A 0.13-µm SiGe BiCMOS dual-band power amplifier (PA) is developed which can be operated at 28 GHz or 60 GHz. The PA employs an LC tank at the input to perform dual-band impedance matching, while the output is switched from one band to the other using a tunable stub. The stub is made tunable by using an HBT switch, which reduces the stub’s length when turned ON shifting the PA between 28 and 60 GHz modes. The switch has 0.7 dB ON- and 0.3 dB OFF-state loss. The measured results exhibit 16.2/11.8 dB small signal gain, 18.4/17.2 dBm saturated output power and 33/21 % peak PAE at 28/60 GHz respectively. The dual-band compact PA has a chip size of 0.55 × 0.52 mm² and consumes a DC current of 11 mA at 3.5 V supply voltage. Within the literature, this is the first demonstration of a 28/60 GHz dual-band PA with performance comparable to dedicated PAs in each band.