| dc.description.abstract | This study employs the WIN Semiconductors′ 0.25 μm GaN and 0.15 μm GaAs high electron mobility transistor (HEMT) commercial processes to design linear Class AB monolithic microwave integrated circuit (MMIC) power amplifiers for the Sub-6 GHz band and the millimeter-wave band, respectively.
The first chip is fabricated using the 0.25 μm GaN HEMT technology and is designed as a single-stage Class AB power amplifier. Its circuit structure comprises a single transistor paired with lumped components such as inductors, resistors, and capacitors to form input and output matching networks. The amplifier operates at a frequency of 3.5 GHz, with theoretical expectations of achieving an output power of 37.41 dBm and a power-added efficiency (PAE) of 53.07%. However, actual measurements show a maximum output power of 29.39 dBm with a corresponding PAE of 16.56%. During 5G NR QPSK and 16-QAM modulated signal testing, the adjacent channel power ratio (ACPR) is approximately -38 and -39 dBc, and the root mean square error vector magnitude (EVM) distortion values are 2.19% and 2.04%, respectively.
The second chip is fabricated using 0.15 μm GaAs pHEMT technology and is designed as a two-stage Class AB power amplifier. Its circuit structure incorporates two transistors, with input, output, and inter-stage matching networks formed using transmission lines, resistors, and capacitors. The amplifier is designed to operate at a frequency of 30 GHz, with theoretical expectations of achieving a saturated output power (Psat) of 23.19 dBm, a maximum power-added efficiency (PAE) of 32.69%, and a 1-dB compression point output power (OP1dB) of 21.34 dBm. However, measurement results show that at an operating frequency of 28 GHz, the saturated output power is 21.46 dBm, with a maximum PAE of 33.54% and an OP1dB of 14.70 dBm. At 30 GHz, the measured saturated output power drops to 15.91 dBm, the maximum PAE is 6.53%, and the OP1dB is 13.40 dBm. In the 5G NR QPSK, 16-QAM, and 256-QAM modulated signal measurements, the ACPR values are ?22 dBc, ?23 dBc, and ?33 dBc, respectively. According to the 5G NR Release 15 standard, the maximum allowable EVM for these three modulation signals is 17.5% for QPSK, 12.5% for 16-QAM, and 3.5% for 256-QAM. The corresponding output power levels are respectively 14.27 dBm, 13.18 dBm, and 3.71 dBm. | en_US |