Large, lightweight, high power, L-band phased-arrays
are required to enable future NASA synthetic aperture
radar (SAR) missions. The transmit/receive (T/R) module is a
key component in SAR antennas and the T/R module efficiency
has direct implications on the power dissipation and power
generation requirements of the system. Significant
improvements in the efficiency of the T/R module will make
SAR missions more feasible and affordable. The efforts
described in this paper are part of a three-year on-going task sponsored by the NASA Earth Science Technology Office
(ESTO) under the Advanced Component Technology (ACT)
program. We will describe the current status and recent results of a novel T/R module technology to achieve ultra-high efficiencies. The T/R module performance goal is to achieve an overall module efficiency greater than 70% with a minimum of 30-Watts output power at L-band frequencies
