Analysis of a GaN/SiC UHF Radar Amplifier for Operation at 125 V Bias

The relationship between Fe concentration in the buffer layer and breakdown voltage of an AlGaN/GaN on SiC HEMT transistor has been investigated to achieve operation of the device in a UHF power amplifier operated at a bias of 100V or higher. A 15mm transistor has been tested in a power amplifier at the frequency of 430MHz with a 100µs pulse and 10% duty factor, operated at 75V, 100V, 125V and 150V bias. At 100V bias, the device achieves 250W output power and 78% drain efficiency with 27dB gain almost independently of Fe content; at 125V bias, only the devices with Fe content above 1e18 cm-3 achieve a saturated power in excess of 350W with 75% drain efficiency and 27dB gain. RF burn-in tests indicate very stable operation. To the authors’ knowledge, this is the first time that UHF pulsed radar amplifier operation has been reported at voltages above 100V with GaN technology.

Please note: By downloading a white paper, the details of your profile might be shared with the creator of the content and you may be contacted by them directly.