Abstract
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.
Highlights
With increasing spectral demands, the use of millimeter-wave frequencies is envisaged in the near future [1]
The potential of several mm-wave bands has been investigated for mobile or vehicular applications [2,3], with the 28 GHz band becoming a part of the 5G New Radio (NR) standard, while the 60 GHz band is promising in terms of its unlicensed access to spectra [4]
In the designed test-bed, the RX part serves as the observation receiver [45,46] for digital predistortion (DPD) adaptation and there is neither carrier nor sampling frequency mismatch as the radio frequency (RF) local oscillator and the clock source of A/D and D/A converters are shared for both TX and RX sides
Summary
The use of millimeter-wave (mm-wave) frequencies is envisaged in the near future [1]. One of the most severe RF front-end impairments is power amplifier (PA) nonlinearity [18] This results in out-of-band radiation that is less problematic in the mm-waves due to the spatial separation of the links, and in in-band signal distortion that needs to be compensated. A multi-Gb/s general-purpose AWG and oscilloscope have been used in a recent demonstration of DPD in the 28 GHz band [35] The use of such general-purpose equipment significantly increases the costs of the overall system and prohibits the wider deployment of predistortion in commercial mm-wave applications. The described test-bed is fully MATLABcontrolled and, in contrast to similar recent setups, it contains digital compensation for the RF front-end including amplitude and phase mismatch and power amplifier linearization using digital predistortion.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
