Abstract: A microwave antenna has a rectangular section waveguide with two narrow walls and and two broad walls. Towards one end, the waveguide is coupled with a microwave transition by which a coaxial connector can be coupled to the waveguide. The transition has a conductor extending through a narrow wall and connected internally with a transition plate. The transition plate extends longitudinally, centrally along the waveguide and is stepped to provide a quarter wave section.

Abstract: A marine radar antenna has a single dielectric plate mounted in front of the waveguide polarization grid between two horn plates. A strip of dielectric material is secured to the upper and lower surfaces of the plate to form a forwardly and rearwardly facing step on each surface. The steps are located forwardly of the ends of the horn plates and are positioned to produce reflections substantially 180° out of phase with extraneous energy within the antenna. The dielectric plate is supported by a foamed plastics material within an outer radome.

Abstract: A microwave antenna has a rectangular section waveguide with two narrow walls and and two broad walls. Towards one end, the waveguide is coupled with a microwave transition by which a coaxial connector can be coupled to the waveguide. The transition has a conductor extending through a narrow wall and connected internally with a transition plate. The transition plate extends longitudinally, centrally along the waveguide and is stepped to provide a quarter wave section.

Abstract: A marine radar antenna has a single dielectric plate mounted in front of the waveguide polarisation grid between two horn plates. A strip of dielectric material is secured to the upper and lower surfaces of the plate to form a forwardly and rearwardly facing step on each surface. The steps are located forwardly of the ends of the horn plates and are positioned to produce reflections substantially 180° out of phase with extraneous energy within the antenna. The dielectric plate is supported by a foamed plastics material within an outer radome.

Abstract: A tire temperature measurement apparatus comprising a microwave receiver (9 or 11) sensitive to electromagnetic radiation in a waveband in the frequency spectrum 10 to 100 GHz and a directional antenna (5 or 7) coupled to the receiver input and responsive to radiation from a predetermined surface area only of the tire (1 or 3).