Abstract: A spacecraft payload subsystem includes a tracking receiver, an input multiplexer, an antenna pointing mechanism (APM) controller and a plurality of antenna reflectors. Each antenna reflector is mechanically coupled with a respective APM, and illuminated by a respective tracking feed element. Each respective tracking feed element is configured to receive an uplink beacon signal from the ground by way of one of the antenna reflectors and is coupled, by way of a respective pseudo-monopulse (PSM) coupler and the input multiplexer, to the tracking receiver. The tracking receiver is configured to receive multiplexed signals from the PSM couplers by way of the input multiplexer and output corresponding pointing error information to the APM controller. The APM controller is configured to send commands to one or more of the APMs. Each APM is configured to point a respective antenna reflector in response to the commands.

Abstract: A spacecraft communications payload includes a beam forming network (BFN), wherein the BFN includes a first feed waveguide and a first set of branch waveguides, each branch waveguide in the first set operating in a frequency band having a characteristic waveguide wavelength ?g1. A proximal portion of the first set of branch waveguides is communicatively coupled with the first feed waveguide. A distal portion of the first set of branch waveguides is communicatively coupled by way of an array of slots with a plurality of radiating elements. A separation distance between adjacent slots in the array is approximately equal to ?g, and the array of slots is configured as a honeycomb-like triaxial lattice. In some implementations, a compact BFN may be configured to simultaneously operate at two different polarizations (“dual-polarized”) and/or frequency bands (“dual-band”).

Abstract: A spacecraft communications payload includes a beam forming network (BFN), wherein the BFN includes a first feed waveguide and a first set of branch waveguides, each branch waveguide in the first set operating in a frequency band having a characteristic waveguide wavelength ?g1. A proximal portion of the first set of branch waveguides is communicatively coupled with the first feed waveguide. A distal portion of the first set of branch waveguides is communicatively coupled by way of an array of slots with a plurality of radiating elements. A separation distance between adjacent slots in the array is approximately equal to ?g, and the array of slots is configured as a honeycomb-like triaxial lattice. In some implementations, a compact BFN may be configured to simultaneously operate at two different polarizations (“dual-polarized”) and/or frequency bands (“dual-band”).