Hae Cheon Kim

0.15 /spl mu/m gate length InAlAs/InGaAs power metamorphic HEMT on GaAs substrate with extremely low noise characteristics

The 0.15 /spl mu/m gate-length power metamorphic HEMTs (MHEMT) with wide head T-shaped gate has been fabricated and the DC, microwave, and noise performance of the device were characterized. The MHEMT device shows the DC output characteristics having an extrinsic transconductance of 740 mS/mm and a threshold voltage of -0.75 V. The f/sub T/ and f/sub max/ obtained for the 0.15 /spl mu/m /spl times/ 100 pm MHEMT device are 150 GHz and 240 GHz, respectively. The MHEMTs exhibit the minimum noise figure, NF/sub min/, of 0.79 dB and associated gain of 10.5 dB at 26 GHz. The NF/sub min/ measured at 40 GHz is 1.21 dB with associated gain of 6.41 dB. This noise data is the lowest value ever reported for power MHEMT devices with InGaAs channel of 53% In. The excellent noise characteristics might result from the low gate resistance due to the wide head T-shaped gate and the improved device performance.

0.15 /spl mu/m gate length MHEMT technology for 77 GHz automotive radar applications

The 0.15 /spl mu/m gate-length power metamorphic HEMTs (MHEMT) with wide head T-shaped gate has been fabricated and the DC, and microwave performance of the device were characterized. The MHEMT device shows the DC output characteristics having an extrinsic transconductance of 740 mS/mm and a threshold voltage of -0.75 V. The f/sub T/ and f/sub max/ obtained for the 0.15 /spl mu/m /spl times/ 100 /spl mu/m MHEMT device are 150 GHz and 240 GHz, respectively. A MMIC 77 GHz 3-stage amplifier is reported in this paper. This MMIC chip demonstrated a measured small signal gain of over 12 dB from 70 GHz to 79 GHz with 7 dBm output power at 1 dB compression. The maximum small signal gain is above 13.5 dB from 77 to 78 GHz. This chip is fabricated using 0.15 /spl mu/m MHEMT process based on 4-inch substrate. This MMIC chip size is 1.7 mm /spl times/ 2 mm. This MMIC amplifier chip is suitable for the 77 GHz automotive radar systems and related transmitter applications in W-band.