A highly reliable ultra-wideband GaN power amplifier for high-speed transportation communication systems

Abstract In response to the demand for high-frequency ultra-wideband power amplifiers (PAs) in high-speed reliable communication fields such as high-speed railway and highway transportation, a single-chip integrated circuit (MMIC) for ultra-wideband PAs operating in 2–6 GHz based on 0.25 μm GaN process is proposed in this paper. For high-speed communication in transportation applications, the PA achieves the optimal output impedance through the load/source pull method, employs a resistor capacitor (RC) parallel network to enhance stability, and utilizes an RLC/LC bias circuit to ensure the stability performance of the radio frequency (RF) circuit. The paper innovatively proposes a method for optimizing full frequency impedance matching through RC curve fitting and combines electro-magnet (EM) co-simulation to achieve 50 Ω impedance matching, significantly improving design efficiency and accuracy. The measured results show that the GaN MMIC PA has an output power greater than 39 dBm, a power gain greater than 18 dB, and a power-added efficiency (PAE) greater than 37% (peak 48.2%) in the 2–6 GHz frequency band. The overall size of the chip is 1.9 mm × 2.4 mm. This paper can provide guidance for core components of high-speed transportation communication systems, meeting the diverse requirements of high-speed wireless communication in the transportation field for transmitters.