Polarization-sensitive receiver for microwave signals

Claim 2

An improved microwave receiver for microwave radiation sensitive to the polarization of the incoming signal, comprising: a planar reflecting mirror for reflecting received microwave radiation and being rotatable around a principal axis and aligned at substantially 45 degrees with respect thereto; a flat, polarizing filter, constructed from a material substantially transparent to microwave radiation, said filter being substantially in orthogonal alignment with, and substantially centered on, said principal axis of rotation, and said filter being in the path of radiation reflected from said planar reflecting mirror and synchronously driven with respect thereto; a first, circular, transmitting region in said polarizing filter, substantially centered on said axis of rotation; a second, annular, partially transmitting region abutting on said first region, defined by a plurality of substantially parallel, electrically conductive, grid lines substantially opaque to microwave radiation; a third, annular, partially transmitting region abutting on said second region and positioned radially outwardly therefrom, defined by a plurality of substantially parallel, electrically conductive, striations substantially opaque to microwave radiation, with said striations aligned at substantially right angles with respect to said grid lines; first receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said first region of the polarizing filter; second receiving means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said second region of the polarizing filter; and third receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said third region of the polarizing filter.

Claim 3

The microwave receiver of claim 1, wherein said parallel grid lines are also substantially parallel to elements of said planar reflecting mirror orthogonal to said principal axis of rotation.

Claim 4

The microwave receiver of claim 2, additionally comprising drive means for entraining said mirror and said filter disk into synchronized rotation about said principal axis of rotation.

Claim 5

The microwave receiver of claim 3, further comprising a parabolic antenna for microwave radiation and having front, focusing surface and a rear, non-focusing surface said planar reflecting mirror being mounted on the rear surface of the parabolic antenna.

Claim 6

The microwave receiver of claim 3, additionally incorporating means for measuring signal strengths received by said first, second and third receiver means.

Claim 7

The microwave receiver of claim 5, wherein said means for measuring signal strengths includes at least one measurement channel, with such measurement channel including: waveguide means for conveying microwave radiation sensed by said receiver means; a microwave diode communicating with the output end of said waveguide means; and a microammeter connected to the output of said diode.

Claim 8

The microwave receiver of claim 1, wherein said parallel grid lines are parallel to said principal axis of rotation.

Claim 9

The microwave receiver of claim 1, wherein said first, transmitting region in said filter is small in radial extent, and said first receiver means is omitted.

Claim 10

The microwave receiver of claim 1, wherein the width of each of said grid lines and each of said striations is small compared to the wavelength of the incoming microwave signal and wherein the distance between longitudinal center lines of adjacent grid lines and between longitudinal center lines of adjacent striations is large compared to the width of each of said grid lines and each of said striations.

Claim 11

The microwave receiver of claim 9, wherein the width of each of said grid lines and each of said striations is between about 0.005 inch and about 0.025 inch, and wherein the distance between longitudinal center lines of adjacent grid lines and between longitudinal center lines of adjacent striations is between about 0.030 inch and 0.100 inch.

Claim 12

An improved microwave receiver for microwave radiation sensitive to the polarization of the incoming signal, comprising: an antenna for transmitting and receiving microwave radiation having vertical and horizontal components and having a front, focusing surface and a rear, non-focusing surface; a planar reflecting mirror for reflecting received microwave radiation and being rotatable around a principal axis common to the antenna and aligned at substantially 45 degrees with respect thereto and being mounted on the rear surface of the antenna; a flat, polarizing filter, constructed from a material substantially transparent to microwave radiation, said filter being substantially in orthogonal alignment with, and substantially centered on, said principal axis of rotation, and said filter being in the path of radiation reflected from said planar reflecting mirror and synchronously driven with respect thereto; a first, circular, transmitting region in said polarizing filter, substantially centered on said axis of rotation; a second, annular, partially transmitting region abutting on said first region, defined by a plurality of substantially parallel, electrically conductive, grid line substantially opaque to microwave radiation; a third, annular, partially transmitting region abutting on said second region and positioned radially outwardly therefrom, defined by a plurality of substantially parallel, electrically conductive, striations substantially opaque to microwave radiation, with said striations aligned at substantially right angles with respect to said grid lines; first receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said first region of the polarizing filter; second receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said second region of the polarizing filter; and third receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said third region of the polarizing filter; wherein the second and third partially transmitting regions filter the received microwave signal into its horizontal and vertical components; and means for comparing the radiation received by the first , second and third receiver means.

Claim 13

An improved microwave receiver for microwave radiation sensitive to the polarization of the incoming signal, comprising: an antenna for transmitting and receiving microwave radiation having vertical and horizontal components and having a front, focusing surface and a rear, non-focusing surface; a planar reflecting mirror for reflecting received microwave radiation and being rotatable around a principal axis common to the antenna and aligned at substantially 45 degrees with respect thereto and being mounted on the rear surface of the antenna; a flat, polarizing filter, constructed from a material substantially transparent to microwave radiation, said filter being substantially in orthogonal alignment with, and substantially centered on, said principal axis of rotation, and said filter being in the path of radiation reflected from said planar reflecting mirror and synchronously driven with respect thereto; a first, circular, transmitting region in said polarizing filter, substantially centered on said axis of rotation; a second, annular, partially transmitting region abutting on said first region, defined by a plurality of substantially parallel, electrically conductive, grid line substantially opaque to microwave radiation; a third, annular, partially transmitting region abutting on said second region and positioned radially outwardly therefrom, defined by a plurality of substantially parallel, electrically conductive, striations substantially opaque to microwave radiation, with said striations aligned at substantially right angles with respect to said grid lines; first receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said first region of the polarizing filter; second receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said second region of the polarizing filter; and third receiver means, positioned behind the face of said polarizing filter remote from said planar reflecting mirror and aligned to receive radiation reflected therefrom through said third region of the polarizing filter; wherein the second and third partially transmitting regions filter the received microwave signal into its horizontal and vertical components; and means for comparing the radiation received by the first , second and third receiver means.

Claim 14

The microwave receiver of claim 11, wherein said parallel grid lines are also substantially parallel to elements of said planar reflecting mirror orthogonal to said principal axis of rotation.

Claim 15

The microwave receiver of claim 12, additionally comprising drive means for entraining said mirror and said filter disk into synchronized rotation about said principal axis of rotation.

Claim 16

The microwave receiver of claim 13, wherein said antenna is a parabolic antenna.

Claim 17

The microwave receiver of claim 13, additionally incorporating means for measuring signal strengths received by said first, second and third receiver means.

Claim 18

The microwave receiver of claim 15, wherein said means for measuring signal strengths includes at least one measurement channel, with such measurement channel including: waveguide means for conveying microwave radiation sensed by said receiver means; a microwave diode communicating with the output end of said waveguide means; and a microammeter connected to the output of said diode.

Claim 19

The microwave receiver of claim 11, wherein said parallel grid lines are parallel to said principal axis of rotation.

Claim 20

The microwave receiver of claim 11, wherein said first, transmitting region in said filter is small in radial extent, and said first receiver means is omitted.

Claim 21

The microwave receiver of claim 11, wherein the width of each of said grid lines and each of said striations is small compared to the wavelength of the incoming microwave signal and wherein the distance between longitudinal center lines of adjacent grid lines and between longitudinal center lines of adjacent striations is large compared with the width of each of said grid lines and each of said striations.

Claim 22

The microwave receiver of claim 19, wherein the width of each of said grid lines and each of said striations is between about 0.005 inch and about 0.025 inch, and wherein the distance between longitudinal center lines of adjacent grid lines and between longitudinal center lines of adjacent striations is between about 0.030 inch and 0.100 inch.