Innovative technologies for the developments of W-band radars and communication payloads

The present work, that has been performed in the frame of the ASI (Italian Space Agency) program WAVE (W-band analysis and verification), i.e. the identification of innovative technologies to be used for the design and development of on-board W-band radars or telecommunication payloads. The paper provides and comments on the major results achieved in this investigation. Based on the state of the art of the present technology the possibility of developing low level W band MMICs with many functions integrated on the same chip has been investigated in order to reduce drastically the number of interconnections, the number of measurements and the workmanship with respect to the equivalent hybrid subsystems, which means a drastic reduction in terms of dimensions, weight and costs. As for the power is concerned, an analysis of the performances of MMICs developed using state-of-the-art consolidated monolithic processes has been carried out together with the analysis of the potential performance of new "wide band-gap" semiconductors that start to play an important role in terms of power and efficiency. At W-band, WR-10 waveguide losses play a significant role in the management of the performance of transmitter and receiver chains and of antennas feeds. In order to reduce such losses different technologies have to be explored. One of those is quasi optics. Quasi-optics is the name given to the technique of manipulating mm-wave signals in free-space beams through the use of quasi-optical components such as lenses, mirrors, polarisers and so on. Quasi-optics (QO) has a number of advantages over other transmission techniques (such as waveguide and microstrip), including low loss propagation and wide bandwidth capacity