Claims
- 1. 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.
- 2. An antenna as in claim 1 wherein the conductive grating is formed on an interior surface of the dome.
- 3. An antenna as in claim 1 wherein the conductive grating is formed of a plurality of parallel conductors with a spacing typically less than one-fifth of the wavelength of a carrier frequency used in the wireless communication system.
- 4. An antenna as in claim 1 wherein the twist reflector further comprises:
a metal plate having grooves formed in a surface facing the conductive grating.
- 5. An antenna as in claim 1 wherein the twist reflector further comprises:
a methal backed dielectric layer, the dielectric layer having grooves formed therein to import the polarization.
- 6. An antenna as in claim 4 wherein the grooves formed in the metal plate have a depth of about one-quarter of the wavelength of a carrier frequency used in the wireless communication system.
- 7. An antenna as in claim 4 wherein approximately one to three grooves are formed in the twist plate per wavelength of a carrier frequency used in the wireless communication system.
- 8. An antenna as in claim 1 wherein the twist reflector further comprises:
a metal-backed dielectric layer with conductive grating created on its forward surface.
- 9. An antenna as in claim 1 wherein the twist reflector is additionally formed on an external face of a housing in which are enclosed a radio transceiver for receiving microwave data signals on a carrier frequency.
- 10. An antenna as in claim 8 wherein the twist reflector further serves as a heat sink for electronic components of the radio transceiver.
- 11. An antenna as in claim 1 wherein a feed point is disposed at the twist reflector along the axis of reception.
- 12. 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.
- 13. A radio unit as in claim 12 wherein the conductive grating is formed of a plurality of parallel conductors with a spacing typically less than one-fifth of the wavelength of the microwave carrier frequency.
- 14. A radio unit as in claim 12 wherein the twist reflector further comprises:
a metal plate having grooves formed in a surface facing the conductive grating.
- 15. A radio unit as in claim 14 wherein the grooves formed in the twist plate have a depth of about one-quarter of the wavelength of the microwave carrier frequency.
- 16. A radio unit as in claim 14 wherein approximately one to three grooves are formed in the twist plate per wavelength of the microwave carrier frequency.
- 17. A radio unit as in claim 12 wherein the twist reflector further comprises a metal backed dielectric layer with a conductive grating created on its forward side.
- 18. A radio unit as in claim 12 wherein the twist reflector is additionally formed on an external face of a housing in which are enclosed a radio transceiver for receiving microwave data signals on the microwave carrier frequency.
- 19. A radio unit as in claim 18 wherein the twist reflector further serves as a heat sink for electronic components of the transceiver.
- 20. A radio unit as in claim 12 wherein the feed point is disposed at the twist reflector along the axis of reception.
- 21. 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.
- 22. A method as in claim 21 additionally comprising the step of:
allowing a carrier substrate to remain integral to the resulting molded transreflector article.
- 23. A method as in claim 21 additionally comprising the step of:
introducing a fluid synthetic resin into said mold cavity to form the desired transreflector element with said spaced parallel stripes disposed on an internal concave surface thereof.
- 24. A method of making a transreflector according to claim 21 in which the resin of the carrier film is a low loss dialectric.
- 25. A method of making a transreflector according to claim 21 wherein the resin of said carrier film is a polyester.
- 26. A method of making a transreflector according to claim 21 wherein the transreflector element is a generally circular configuration.
- 27. The method of making a transreflector according to claim 21 wherein the step of forming spaced parallel stripes comprises physical vapor deposition of a metal.
- 28. A method as in claim 21 wherein the step of forming the conductive pattern comprises the steps of etching a conductive substrate.
- 29. A method as in claim 28 in which the conductive substrate is pad printed or silk screened.
- 30. A method of making a transreflector as in claim 21 wherein the step of forming the conductive pattern on the substrate comprises etching a pre-clad material.
RELATED APPLICATION(S)
[0001] This application is a continuation-in-part of a prior U.S. patent application Ser. No. 09/317,767, filed May 24, 1999, entitled “Transreflector Antenna For Wireless Communication System.” The entire teachings of the above application(s) are incorporated herein by reference.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09317767 |
May 1999 |
US |
Child |
10081035 |
Feb 2002 |
US |