Guidance apparatus with dual mode sensor

Apparatus for producing guidance signals relative to a target in conjunction with associated transmitter and receiver apparatus comprising:

• a) a window transparent to both infrared and radio frequency radiation;
• b) an infrared detector positioned behind said window and producing a first guidance signal upon detection of infrared radiation from the target;
• c) a dual reflector-antenna assembly positioned behind said window comprising:
• i) a chemical vapor deposited substrate of dielectric material,
• ii) a plurality of radio frequency antenna elements formed upon said substrate and arranged to define an antenna beam axis, and
• iii) reflective means reflective to infrared radiation and supported upon said substrate for receiving infrared radiation transmitted through said window, for concentrating said transmitted infrared radiation upon said infrared detector, and for defining an infrared detection beam axis coincident with said antenna beam axis;
• and
• d) a transmission line coupled to said radio frequency antenna elements, said transmission line supplying radio frequency energy generated by associated transmitter apparatus to said radio frequency antenna elements to form a beam of radio frequency radiation, said transmission line also supplying a second guidance signal to associated receiver apparatus, said second guidance signal corresponding to radio frequency radiation reflected from a target through said window along said antenna beam axis.

Apparatus for producing guidance signals for a tactical missile in conjunction with associated transmitter and receiver apparatus, comprising:

• a) a window transparent to both infrared and radio frequency radiation;
• b) an infrared detector producing a first guidance signal upon detection of infrared radiation from a target;
• c) a dual reflector-antenna assembly positioned behind said window comprising:
• i) a chemical vapor deposited substrate of dielectric material, said substrate having an aperture therethrough and supporting said infrared detector at the end of said aperture opposite said window;
• ii) a plurality of microstrip radio frequency antenna elements formed within said substrate by metalization techniques and arranged in an array to define an antenna beam axis, and
• iii) a reflective surface reflective to infrared radiation and transparent to radio frequency radiation formed on the side of said substrate closest to said window, and said reflective surface concentrating infrared radiation transmitted through said window parallel to an infrared detection axis coincident with said antenna beam axis;
• d) a secondary reflector positioned between said window and said reflector assembly to form a Cassegrainian optical system with said reflective surface, said secondary reflector reflecting said concentrated infrared radiation through said aperture to said infrared detector;
• and
• e) a transmission line coupled to said antenna elements and supplying radio frequency energy generated by associated transmitter apparatus to said antenna elements to form a beam of radio frequency radiation coincident with said antenna beam axis, said transmission line also supplying a second guidance signal to associated receiver apparatus, said second guidance signal corresponding to radio frequency radiation reflected from a target through said window along said antenna beam axis.

A method for forming a dual reflector-antenna assembly for guidance signal producing apparatus, comprising the steps of:

• forming a base of dielectric material;
• polishing the base into a curved surface corresponding generally to the desired curve of a radio frequency antenna system;
• forming a radio frequency ground plane of conductive material on the curved surface by a thin-film metalization process;
• forming first layers of dielectric material by a chemical vapor deposition process upon the ground plane;
• polishing the first dielectric layers;
• depositing a plurality of radio frequency antenna components by a thin-film metalization process upon the first dielectric layers;
• depositing second layers of dielectric material by a chemical vapor deposition process to form a surface even with the antenna components;
• polishing the even surface;
• depositing material transparent to radio frequency radiation and reflective to electro-optical radiation by a chemical vapor deposition process upon the polished even surface to form a reflective coating;
• and
• polishing the reflective coating to form a high quality reflective surface.