High Power, Thermally Efficient, X-band 3D T/R Module With Calibration Capability for Space Radar

Earth observation from space radar is based on the active electronically steerable antenna (AESA) whose performances count on reliable and powerful transmit/receive modules (TRM). To this aim, as a follow-up of the successful demonstration of a low-footprint transmit/receive hybrid module concept based on 3-D packaging and interconnect technologies (3DTRM), the interest for carrying out additional development work took a further step aiming at achieving a three-fold module performance improvement as well as at consolidating the novel proposed 3-D technology for space applications. First, the possibility of performing an AESA highly accurate calibration was implemented by embedding a wide band, high directivity directional coupler in the module circuitry without any total module footprint increase. Second, the heat extraction capability of the metal-ceramic hermetic package was enhanced through a re-design of the monolithic microwave integrated circuit (MMIC)-to-sink interface. And finally, the gallium arsenide (GaAs) MMIC high power amplifier (HPA) of the first 3DTRM version was replaced by a gallium nitride (GaN) HPA MMIC, obtaining both a higher transmit output power at 5 dB of compressed gain and an improved power added efficiency (PAE) at module level.