Three-stage transformer-coupled CMOS power amplifier for millimeter-wave applications using 130 nm CMOS technology

High-efficiency and high-linearity three-stage transformer-coupled power amplifier (PA) and power combiner for millimeter-wave applications using 130 nm CMOS technology are presented in the paper. The suggested PA uses transformer coupled for input, inter-stage, and output matching networks where the inter-stage matching inductors are utilized to enhance the RF performance. The proposed power amplifier is composed of three stages: first, driver, and power stages. The first stage operates in a class-C to improve the efficiency and decrease power dissipated while a class-AB is used in the driver and power stages to maximize the output power. The proposed PA and power combiner designs are suitable for mm-wave 5G applications. The coupling transformers, inter-stage matching inductors, and output combiner are analyzed and designed using Ansoft high-frequency structure simulator (HFSS) and achieve high-quality factor and high-coupling coefficient over the frequency range from 26 to 33 GHz. The proposed three-stage transformer-coupled power amplifier covers a frequency band from 26 GHz to 33 GHz with a saturated output power of 13.1 dBm, a peak power added efficiency (PAE) equals 19.1%, and a maximum power gain of 13.25 dB. Whereas the proposed power combiner has a saturated output power of 16.3 dBm, a maximum PAE equals 20.5% and a peak gain of 16.5 dB. The proposed three-stage transformer-coupled PA and power combiner consume low power of 65 mW and 128 mW, respectively. Moreover, the adjacent channel power ratios (ACPR) of the proposed PA and power combiner equal -30 dBc and -36 dBc, respectively, for 20 MHz channel bandwidth. Finally, the active areas of the proposed power amplifier and power combiner equal 0.25 mm(2) and 0.69 mm(2), respectively, while the chip areas are 0.55 mm(2) and 1 mm(2), respectively.