Advances in design of L-band lightweight receiver for phased array applications [satellite communications]

Describes a L-band receiver developed under European Space Agency (ESA) contract by Marconi Space Systems as part of the Advanced Technology and Systems Programme (ATSP). The receiver operates in the INMARSAT return link (ship to shore) frequency band of 1626.5 to 1656.5 MHz. A single down conversion is made to 250 MHz of intermediate frequency (IF) to alleviate filtering requirements but yet to stay within capabilities of SAW filters. Such receivers are intended for applications in spacecraft multiple beam phase array front ends. Hence design and development of such receivers not only demands state of the art performance but also very low mass and high degree of producibility to ensure accurate tracking and alignment between relatively large number of receive elements. The critical performance parameters of this receiver are an overall noise figure (NF) of 1.5 dB with corresponding gain of 60 dB, and multicarrier (i.e 125) C/I₃ of 60 dB, over an acceptance temperature range of -5°C to +55°C. In addition to this RF performance a major design driver has been to reach a mass target of 200 gms. The author describes the receiver system in full but dwells on low noise amplifiers (LNAs) and RF filter which represent advanced design technology