Performance Characterization of Power Amplifier Integrated into D-Band Front-End with Different Modulation Schemes

This paper proposes a measurement system to perform the characterization of a D-band RF front-end (RFFE) device under test (DUT) with various modulation schemes. First, a developed RFFE with an integrated power amplifier was tested and simulated, in a power-controlled continuous wave system, to characterize and model its nonlinearly compensated behavior at 142 GHz. The results have shown that the system can be pushed toward its compression region, supported by a look-up table model. The wideband modulated performance of the RFFE was experimentally validated with single carrier (SC) and eight component carriers 5G new radio orthogonal frequency division multiplexing (5GNR OFDM) signals which can be measured in terms of error vector magnitude (EVM) and adjacent channel power ratio (ACPR), which ran on an accurate RF power control system. A narrow-band model was also simulated to validate the wide-band results. The measured ACPR performance of the SC was 2-3 dB better than 5GNR OFDM due to a lower crest factor. The best system de-embedded EVM of the front-end was 1.5 % with SC of 64-QAM and a rolloff factor at 0.22. The SC provided in 16-QAM 6 dB and in 64-QAM 8 dB more power than the 5GNR OFDM at the same EVM level.