Recently, the GaN research team of the High Frequency and High Voltage Center of the Institute of Microelectronics, led by Researcher Liu Xinyu, has conducted innovative research and exploration in research directions such as high-frequency and high-efficiency devices, limiters, and power drive circuits, and has made important progress.
In the field of high-frequency and high-efficiency devices, the team used LP-SiN combined with ALD ultra-thin gate dielectric technology to prepare 0.15μm gate length AlGaN/GaN millimeter-wave MIS-HEMT power devices, which solved the problems of large Schottky leakage and low efficiency of existing HEMT devices.
Under continuous wave test conditions, the power added efficiency (PAE) at 30GHz was 49.7% and the power density was 5.90W/mm.
In the direction of limiters, the team used a limiter based on all-GaN SBD-MMIC technology, and used monolithic microwave integrated circuit (all-GaN SBD-MMIC) technology implemented by all-GaN Schottky barrier diodes. The developed limiter showed high incident power of more than 50W in continuous wave mode (CW) and 125W in pulse mode, with insertion loss (IL) less than 1dB@8GHz and a record fast recovery time of 39 nanoseconds, which expanded the application prospects of wide bandgap materials in the field of GaN SBD limiters.
In the direction of power drive circuit, the team developed a GaN-based monolithic envelope tracking power modulator, which integrates the prevention stage required by traditional GaN switching power amplifiers and adopts a double-ended anti-bootstrap circuit to achieve tracking of 20MHz bandwidth and 6.5dB RF envelope signals; the power modulator is used to power the continuous class F PA to realize envelope tracking power amplifier application. At 2.7GHz carrier frequency, 20MHz signal bandwidth, 6.5dB peak-to-average power ratio and 30.6dBm output power, the system efficiency is 8% higher than that of a single PA.
