High Performance C-/Ka-Band Coaxial Circulators

The input multiplexer and the low power circulators are crucial components in a satellite communication payload. In modern multimedia satellites the complexity of the payload is increased by adding more and more signal processing features to the simple amplification, and the role of the input multiplexer therefore becomes even more pronounced. The project focuses on C- and Ka-band circulators and isolators.

The general task of the output network is to combine all channels to one waveguide called manifold. The output network consists of isolators, switches, channel filter and the manifold. The first task of the isolator is to terminate the power amplifier. The output of the isolator is connected to a switch, which provides the signal to channel filter. The second task of the isolator is to protect the power amplifier. Two typical failure scenario are: The switch is in the wrong position or the RF frequency has not the channel frequency. In both cases the RF signal will be totally reflected at the switch or the filter and propagates back to the load of the circulator. At both failures the power amplifier is still terminated with the same impedance and is protected. The power of the backward propagating wave is terminated in the load. The project focuses on C-band high power circulators and loads with coaxial interfaces.