Transreflector antenna for wireless communication system

A radio unit for use in a wireless communication system using microwave radio carrier frequencies, the radio unit comprising:

• an antenna additionally including:
• a housing having a dome shaped exterior portion thereof;
• a focusing transreflector consisting of a conductive grating disposed along a surface of the dome and further defining an axis for the antenna, the orientation of the conductive grating such that radiation having a particular polarization passes through the conductive grating and radiation of other polarizations is reflected by the conductive grating;
• a twist reflector substantially centered along the axis and located at a distance away from the transreflector such that the twist reflector reflects received radiation back towards the focusing transreflector and imparts a polarization to the received radiation thereby reflected so that the focusing transreflector causes the reflected and polarized radiation to be focused along the axis;
• a feed point disposed at the twist reflector along the axis, and arranged to couple transmit energy to the antenna and to couple receive energy from the antenna;
• a microwave transceiver, arranged to couple microwave modulated transmit signals and receive signals to the antenna through the feed point;
• and
• a modem, arranged to provide modulated data signals to the transceiver, and to provide demodulated data signals at an output thereof.

A method for making an antenna for use in a wireless communication system, the antenna comprising:

• a housing having a dome-shaped exterior portion thereof;
• a focusing transreflector consisting of a conductive grating disposed along a surface of the dome and further defining an axis for the antenna, the orientation of the conductive grating such that radiation having a particular polarization passes through the conductive grating and radiation of other polarizations is reflected by the conductive grating;
• and
• a twist reflector substantially centered along the axis and located at a distance away from the transreflector such that the twist reflector reflects received radiation back towards the focusing transreflector and imparts a polarization to the received radiation thereby reflected so that the focusing transreflector causes the reflected and polarized radiation to be focused along the axis;
• wherein the method for making such a transreflector comprising the steps of:
• (a) forming on one surface of a synthetic resin carrier film a series of spaced parallel patterns of a conductive material;
• (b) placing said film on the surface of a mold defining the desired concave internal curve for the transreflector;
• and
• (c) assembling over said film in said spaced relationship a second mold half having the desired convex external curve for the transreflector, said housing providing a mold cavity.