Shinichi Miyakuni

A GSM/EDGE dual-mode, 900/1800/1900-MHz triple-band HBT MMIC power amplifier module

This paper describes a 3.5-V operation HBT MMIC power amplifier module for use in GSM/EDGE dual-mode, 900/1800/1900-MHz triple band handset applications. With diode switches and a band select switch built on the MMIC, the module delivers a P/sub out/ of 35.5 dBm and a PAE of about 50% for GSM900, a 33.4-dBm P/sub out/ and a 45% PAE for GSM1800/1900. While satisfying an error vector magnitude (EVM) of less than 4% and a receive-band noise power of less than -83 dBm/100 kHz, the module also delivers a 29.5 dBm P/sub out/ and a PAE of over 25% for EDGE900, a 28.5 dBm P/sub out/ and a PAE of over 25% for EDGE1800/1900.

A high reliability GaN HEMT with SiN passivation by Cat-CVD

This is the first report of catalytic vapor deposition (Cat-CVD) passivated AlGaN/GaN HEMT. We have found out that the Cat-CVD passivation film with NH3 treatment greatly enhances the reliability of the AlGaN/GaN HEMT. It is rationalized, through the low frequency capacitance-voltage measurement, that the NH3 treatment in the Cat-CVD reactor before the SiN film deposition minimizes the damage at the SiN/AlGaN interface, leading to reducing the surface trap density. The AlGaN/GaN HEMT passivated by the Cat-CVD SiN film suppresses the degradation of an output power to less than 0.4 dB under the RF operation of Vd = 30 V, f = 5 GHz after 200 h.

A Low 1/f Noise and High Reliability InP/GaAsSb DHBT for 76 GHz Automotive Radars

To develop a low 1/f noise and high reliability InP/GaAsSb DHBT, experimental analyses on the recombination current have been carried out. The results show that the recombination current that can affect 1/f noise and reliability originates from the surface of the base. We have optimized the ledge and passivation film on the base surface of InP/GaAsSb DHBT. The optimized DHBT offers 7 dB lower 1/f noise level than the non-optimized DHBT. Additionally, in the high temperature burn-in test, no degradation has been induced even after 1,000 hr. It can satisfy the criterion of automotive radars. The W-band oscillator with the optimized DHBT delivers a remarkably low phase noise of -107 dBc/Hz at 1MHz-offset. This phase noise is 10 dB lower than that of the non-optimized HBT oscillator. These results experimentally confirm that decreasing 1/f noise is effective for the design of a low phase noise oscillator using InP/GaAsSb DHBT. To our knowledge, this is the first report to reveal that the base surface structure of InP/GaAsSb DHBT is a key factor in the improvement of reliability and phase noise.