Broadband group delay waveguide lens
First Claim
1. A broad bandwidth waveguide lens for processing electromagnetic wave energy emanating from a focal point to provide a desired phase distribution at an aperture plane comprising:
- an array of adjacent hollow metallic waveguide elements having parallel longitudinal axes disposed perpendicular to said aperture plane with one of said axes passing through said focal point, each of said waveguide elements having an input port facing said focal point and an output port facing said aperture plane, the respective lengths of said waveguide elements decreasing as a function of transverse distance from said one axis such that the same time delay is provided for electromagnetic wave energy traveling from said focal point to said aperture plane via each of said waveguide elements, and half wave plate phase shifting means disposed in each of said waveguide elements for providing a predetermined phase shift for electromagnetic wave energy propagating through the said waveguide element to provide said desired phase distribution.
0 Assignments
0 Petitions
Accused Products
Abstract
A broadband group delay waveguide lens utilizing an array of half wave plates is disclosed. The lens is comprised of an array of uniformly spaced sections of waveguide having various lengths. The waveguide lengths are selected so as to provide an equal time delay to all rays from the focal point to the aperture plane of the lens. Since equal time delay does not ensure equality of phase at the aperture plane, half wave plates are inserted in the waveguide elements for adjusting the phase of each ray to obtain a constant phase plane over the aperture plane at the design frequency. The inner surface of the lens is spherical with the radius of the sphere equalling the focal length of the lens. The outer surface may be ellipsoidal having a semi-minor axis equal to the focal length and the semi-major axis is dependent upon the waveguide cross section dimensions and the design frequency. Such a lens has a low aperture phase error over a relatively large frequency range.
22 Citations
10 Claims
-
1. A broad bandwidth waveguide lens for processing electromagnetic wave energy emanating from a focal point to provide a desired phase distribution at an aperture plane comprising:
an array of adjacent hollow metallic waveguide elements having parallel longitudinal axes disposed perpendicular to said aperture plane with one of said axes passing through said focal point, each of said waveguide elements having an input port facing said focal point and an output port facing said aperture plane, the respective lengths of said waveguide elements decreasing as a function of transverse distance from said one axis such that the same time delay is provided for electromagnetic wave energy traveling from said focal point to said aperture plane via each of said waveguide elements, and half wave plate phase shifting means disposed in each of said waveguide elements for providing a predetermined phase shift for electromagnetic wave energy propagating through the said waveguide element to provide said desired phase distribution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
9. A broad bandwidth microwave system utilizing a waveguide lens comprising:
-
wave generating means for generating electromagnetic wave energy; a waveguide lens for processing electromagnetic wave energy emanating from said wave generating means to provide a desired phase distribution at an aperture plane, said lens including an array of adjacent hollow metallic waveguide elements having parallel longitudinal axes disposed perpendicular to said aperture plane with one of said axis passing through said wave generating means, each of said waveguide elements having an input port facing said wave generating means and an output port facing said aperture plane, the respective lengths of said waveguide elements decreasing as a function of transverse distance from said one axis such that the same time delay is provided for electromagnetic wave energy traveling from said wave generating means to said aperture plane via each of said waveguide elements, and half wave plate phase shifting means disposed in each of said waveguide elements for providing a predetermined phase shift for electromagnetic wave energy propagating through the said waveguide element to provide said desired phase distribution. - View Dependent Claims (10)
-
Specification