Radiation sensor
First Claim
1. A radiation sensor including a converging dielectric lens arranged to define an optical aperture and an optical axis through the aperture, and wherein:
- (a) the lens incorporates polarization-selective reflecting means for defining first and second focal planes at respective lens surface regions extending across the optical axis,(b) the reflecting means provides for the focal planes to correspond to differing radiation polarization,(c) a first receive array of antennas is located not more than λ
1 from the first focal plane, where λ
1 is an operating wavelength of the sensor measured in a medium adjacent the first focal plane and through which radiation passes to the receive array, each antenna defining a respective radiation beam direction through the lens and being coupled predominantly to radiation passing through the lens, and(d) directionally selective transmitting means couplable to a plurality of output beam directions through the lens are located not more than λ
2 from the second focal plane, where λ
2 is an operating wavelength of the sensor as measured in a medium adjacent the second focal plane through which radiation Passes from the transmitting means.
2 Assignments
0 Petitions
Accused Products
Abstract
A radiation sensor for the microwave and millimeter-wave regions incorporates a lens having two parallel focal planes, these being defined by a polarization-selective reflector grid within the lens. One focal plane is occupied by a receive array of crossed dipole antennas with respective mixer diodes. One dipole of each antenna couples to a local oscillator signal and the other couples to a receive signal reflected by the grid. These signals are mixed by the diodes to produce intermediate frequency signals for subsequent processing. The other focal plane is occupied by a transmit array of separately activatable polarization switching antennas arranged to define a range of transmit beam directions. This focal plane may alternatively be occupied by a second receive array.
37 Citations
20 Claims
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1. A radiation sensor including a converging dielectric lens arranged to define an optical aperture and an optical axis through the aperture, and wherein:
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(a) the lens incorporates polarization-selective reflecting means for defining first and second focal planes at respective lens surface regions extending across the optical axis, (b) the reflecting means provides for the focal planes to correspond to differing radiation polarization, (c) a first receive array of antennas is located not more than λ
1 from the first focal plane, where λ
1 is an operating wavelength of the sensor measured in a medium adjacent the first focal plane and through which radiation passes to the receive array, each antenna defining a respective radiation beam direction through the lens and being coupled predominantly to radiation passing through the lens, and(d) directionally selective transmitting means couplable to a plurality of output beam directions through the lens are located not more than λ
2 from the second focal plane, where λ
2 is an operating wavelength of the sensor as measured in a medium adjacent the second focal plane through which radiation Passes from the transmitting means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A radiation sensor including a converging dielectric lens arranged to define an optical aperture and an optical axis through the aperture, and wherein:
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(a) the lens incorporates polarization-selective reflecting means for defining first and second focal planes at respective lens surface regions extending across the optical axis, (b) the reflecting means provides for the focal planes to correspond to differing radiation polarization, (c) a first receive array of antennas is located not more than λ
1 from the first focal plane, where λ
1 is an operating wavelength of the sensor measured in a medium adjacent the first focal plane and through which radiation passes to the receive array, each antenna defining a respective radiation beam direction through the lens and being coupled predominantly to radiation passing through the lens, and(d) a second receive array of antennas is arranged equivalently to the first receive array to respond to a different radiation polarization, the second receive array being located not more than λ
2 from the second focal plane, where λ
2 is an operating wavelength of the sensor measured in a medium adjacent the second focal plane and through which radiation passes to the second receive array. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification