Abstract

A low-noise X-band microstrip hybrid VCO has been designed and realised using a 2 x 50 µm GaN-on-SiC pseudo-morphic HEMT as the active device. The transistor has been manufactured by TIGER and features a gate-length of 0.15 µm, an fT of 22 GHz, a break-down voltage of 42 Volts and an Idss close to 1 A/mm. The VCO has been assembled with standard SMD reflow and chip-on-board technology on Rogers 4003 substrate material. The circuit is biased at +15 Volts and 38 mA and has a measured tuning range from 8.1 to 10.6 GHz, an output power level of +19 dBm and an average phase-noise level of -114 dBc/Hz @ 1 MHz offset.