A 28GHz Power Amplifier with Analog Predistortion Linearizer in 65nm CMOS

This paper proposes that a radio frequency power amplifier is suitable for a 5G millimeter wave. It adopts a three-stage single-ended structure at 28GHz. An analog predistortion linearization method is used to improve the linearity of the power amplifier (PA). As a result, there is a significant improvement in power-added efficiency (PAE) and linearity is achieved. The Ka-band PA is implemented in TSMC 65nm CMOS process. At 1.2V supply voltage, the PA proposed in this paper achieves a saturated output power of 15.9dBm and a PAE of 16%. After linearization, the output power at the 1dB compression point is increased by 2dBm, with efficient gain compensation performance.

Digitally-Compensated Wideband 60 GHz Test-Bed for Power Amplifier Predistortion Experiments

Millimeter waves will play an important role in communication systems in the near future. On the one hand, the bandwidths available at millimeter-wave frequencies allow for elevated data rates, but on the other hand, the wide bandwidth accentuates the effects of wireless front-end impairments on transmitted waveforms and makes their compensation more difficult. Research into front-end impairment compensation in millimeter-wave frequency bands is currently being carried out, mainly using expensive laboratory setups consisting of universal signal generators, spectral analyzers and high-speed oscilloscopes. This paper presents a detailed description of an in-house built MATLAB-controlled 60 GHz measurement test-bed developed using relatively inexpensive hardware components that are available on the market and equipped with digital compensation for the most critical front-end impairments, including the digital predistortion of the power amplifier. It also demonstrates the potential of digital predistortion linearization on two distinct 60 GHz power amplifiers: one integrated in a direct-conversion transceiver and an external one with 24 dBm output power.