2004 Volume 73 Issue 3 Pages 363-367
Using high-quality diamond homoepitaxial thin films, we fabricated diamond short-gate MESFETs (metal-semiconductor field-effect transistors). FETs exhibited the highest RF characteristics among diamond devices, namely, a transient frequency (fT) of 25GHz, maximum oscillation frequency for a maximum available gain (MAG) (fmax(MAG)) of 63GHz and Mason's unilateral gain (U) (fmax(U)) of 81GHz. Thus, we have achieved amplification in the millimeter wave range for the first time. The power measurements of the A class at 1GHz showed a linear gain of 14dB in a wide range and a maximum output power level of 0.35W/mm. The first RF noise measurements showed a minimum noise figure of 1dB at 3GHz.
