Abstract: A feed having a waveguide with a longitudinal axis. A plurality of corrugations extending from an end of the waveguide. The corrugations coaxial with the longitudinal axis, forming an extension of the waveguide. The corrugations having an end face angle less than 90 degrees with respect to the longitudinal axis to squint the feed beam.

Abstract: A feed having a waveguide with a longitudinal axis. A plurality of corrugations extending from an end of the waveguide. The corrugations coaxial with the longitudinal axis, forming an extension of the waveguide. The corrugations having an end face angle less than 90 degrees with respect to the longitudinal axis to squint the feed beam.

Abstract: A multi-frequency antenna feed for incorporation into a single unit which combines at least two waveguides to provide simultaneous reception and/or transmission of signals in at least two separate frequency bands is described. This is achieved by creating a waveguide system of at least two waveguides sharing the same central axis; a central conventional waveguide which also acts as a center conductor for an outer coaxial waveguide and feeding the outer coaxial waveguide from a non-circular side feed, orthogonal to the waveguide axis, to set up a uniform field in the outer coaxial waveguide. The feeds are adjusted so that the phase center for each frequency band is at the same point in the feed for the same dish. Various embodiments of the invention are described.

Abstract: An RF waveguide signal transition apparatus for minimizing leakage at RF frequency is described which consists of providing a plurality of plated through-holes (16) of blind holes in a circuit board (10). The plated holes (16) are disposed on the circumference of a circle around the RF waveguide to microstrip transition of probe (14) and each of the plated holes (16) is connected to a ground plane (24). The size of distribution of the plated holes provides a barrier to signal leakage at RF frequencies in the range 10.95-11.7 GHz and they also provide a transition impedance similar to the 50 ohm characteristic impedance providing satisfactory matching and minimizing leakage into the board. The apparatus can also be used to minimise leakage from microstrip to microstrip transitions passing through the circuit board.

Abstract: An RF waveguide signal transition apparatus for minimizing leakage at RF frequency is described which consists of providing a plurality of plated through-holes (16) of blind holes in a circuit board (10). The plated holes (16) are disposed on the circumference of a circle around the RF waveguide to microstrip transition of probe (14) and each of the plated holes (16) is connected to a ground plane (24). The size of distribution of the plated holes provides a barrier to signal leakage at RF frequencies in the range 10.95-11.7 GHz and they also provide a transition impedance similar to the 50 ohm characteristic impedance providing satisfactory matching and minimizing leakage into the board. The apparatus can also be used to minimise leakage from microstrip to microstrip transitions passing through the circuit board.