Highly integrated reconfigurable microwave switch matrix module for geostationary satellites

A hybrid integrated 4×4 reconfigurable switch matrix module bearing four redundant paths is presented. Besides standard switching functionality between inputs and outputs, the module exhibits a transparent mode in case of on-board power failure. In the transparent mode, the redundant paths establish a direct transmission between an input and a corresponding output. Owing to the low temperature co-fired ceramic technology, the hermetically sealed module exhibits compact dimensions of 32 mm × 32 mm × 1.7 mm and a light weight of just 6.15 g. The high degree of miniaturization and static power consumption due to the PIN diodes based design raise thermal concerns. Infrared thermographs and finite element thermal simulation modeling provide an estimate of the peak temperature on the package. Compared to its predecessor, the peak temperature of the most recent version was lowered by 22 K with the help of reduced bias currents and thermal vias. The electrical and thermal considerations improve the reliability of the module required for the long-life geostationary satellite. On-wafer measurements revealed an insertion loss of ~(9±1) dB and return loss ≥ 10 dB in normal and transparent modes, and an on-to-off isolation of ≥ 50 dB over the entire Ka-band downlink frequency band (17...22 GHz).