We present GaAs pHEMTs demonstrating output power over 1 W/mm in Ka-band at an operating voltage of 8 V. DC, RF and reliability results are reported. Continuous wave load pull tests at 35 GHz show peak power added efficiency of 52 % and associated gain of 8 dB. The saturated output power of 1.2 W/mm is achieved. Power performance improvement is attributed… (More)
GaN-based RF transistors offer impressive power densities, although to achieve the maximum potential offered by GaN, thermal management must be improved beyond the current GaN-on-SiC devices. By using diamond, rather than SiC substrates, transistor thermal resistance can be significantly reduced. It is important to experimentally verify thermal resistance,… (More)
It is well documented that muscle contraction results from cyclic rotations of actin-bound myosin cross-bridges. The role of actin is hypothesized to be limited to accelerating phosphate release from myosin and to serving as a rigid substrate for cross-bridge rotations. To test this hypothesis, we have measured actin rotations during contraction of a… (More)
The design and performance of a high efficiency Ka-band power amplifier MMIC utilizing a 0.15um high voltage GaAs PHEMT process (HV15) is presented. Experimental continuous wave (CW) in-fixture results for the power amplifier MMIC demonstrate up to 5W of saturated output power and 30% associated power added efficiency at 35GHz.
Thermal conductivity of the substrate affects the performance of high power RF devices. It is a dominant limiting factor in current state-of- the-art GaN HEMTs on SiC substrate. Due to high thermal conductivity, diamond substrate is an attractive alternative for GaN HEMTs. We have developed device quality GaN-on-diamond wafers using CVD diamond and… (More)
The design and performance of a 0.15-um PHEMT high efficiency Ka-band power amplifier MMIC is presented. The 3-stage amplifier utilizes a commercially available production released process with demonstrated reliability and 3metal interconnect (3MI) technology. Experimental continuous wave (CW) in-fixture results for the power amplifier MMIC demonstrate up… (More)