Wide angle, single screen, gridded square-loop frequency selective surface for diplexing two closely separated frequency bands
First Claim
1. A wide angle, single screen, gridded square-loop frequency selective surface for receiving and diplexing two signals in closely separated frequency bands, one of said two signals being at a first frequency and the other of said two signals being at a second frequency, said frequency selective surface comprising a single-screen array of a square grid of intersecting orthogonal x and y conductive elements defining square spaces therebetween and of square-loop conductive patch elements disposed within respective ones of the square spaces, said patch elements being symmetrically spaced with respect to said square grid of intersecting orthogonal x and y conductive elements with each square-loop patch element having respective sides evenly spaced from corresponding ones of said orthogonal x and y conductive elements of said square grid sandwiched between two layers of low loss dielectric material, each layer having a dielectric constant greater than 2 and a thickness of 0.0889 cm, whereby said wide angle, single screen gridded square-loop frequency selective surface will transmit a received signal at said first frequency and reflect a received signal at said second frequency, said second frequency being closely separated from said first frequency, and wherein each side of each square of said square grid around each square-loop patch element has a length P which is 0.3286λ
- , said sides of each square-loop patch element being spaced from each of said x and y conductive elements of said square grid with a spacing G, and said x and y conductive elements of each square of said square grid have a width W1 =0.0205λ
while said square-loop patch elements have a width W2 =0.041λ
on each side thereof, and said transmitted signal at said first frequency is an X-band signal and said reflected signal at said second frequency is a Ku-band signal, whereby the resonant frequency of said transmitted signal at said first frequency is closely separated from said reflected signal at said second frequency with good performance over a wide angle of incidence of radiation from 0°
, normal, to about 40°
from normal.
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Accused Products
Abstract
The design and performance of a wide angle, single screen, frequency selective surface (FSS) with gridded square-loop path elements are described for diplexing closely separated signal bands, for example, X- and Ku-band signals in an Orbiting Very Long Baseline Interferometer (OVLBI) earth station reflector antenna system, as well as other applications such as military and commercial communications via satellites. Excellent agreement is obtained between the predicted and measured results of this FSS design using the gridded square-loop patch elements sandwiched between 0.0889 cm thick tetrafluoroethylene fluorocarbon polymer (PTFE) slabs. Resonant frequency drift is reduced by 1 GHz with an incidence angle from 0° normal to 40° from normal.
39 Citations
3 Claims
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1. A wide angle, single screen, gridded square-loop frequency selective surface for receiving and diplexing two signals in closely separated frequency bands, one of said two signals being at a first frequency and the other of said two signals being at a second frequency, said frequency selective surface comprising a single-screen array of a square grid of intersecting orthogonal x and y conductive elements defining square spaces therebetween and of square-loop conductive patch elements disposed within respective ones of the square spaces, said patch elements being symmetrically spaced with respect to said square grid of intersecting orthogonal x and y conductive elements with each square-loop patch element having respective sides evenly spaced from corresponding ones of said orthogonal x and y conductive elements of said square grid sandwiched between two layers of low loss dielectric material, each layer having a dielectric constant greater than 2 and a thickness of 0.0889 cm, whereby said wide angle, single screen gridded square-loop frequency selective surface will transmit a received signal at said first frequency and reflect a received signal at said second frequency, said second frequency being closely separated from said first frequency, and wherein each side of each square of said square grid around each square-loop patch element has a length P which is 0.3286λ
- , said sides of each square-loop patch element being spaced from each of said x and y conductive elements of said square grid with a spacing G, and said x and y conductive elements of each square of said square grid have a width W1 =0.0205λ
while said square-loop patch elements have a width W2 =0.041λ
on each side thereof, and said transmitted signal at said first frequency is an X-band signal and said reflected signal at said second frequency is a Ku-band signal, whereby the resonant frequency of said transmitted signal at said first frequency is closely separated from said reflected signal at said second frequency with good performance over a wide angle of incidence of radiation from 0°
, normal, to about 40°
from normal. - View Dependent Claims (2, 3)
- , said sides of each square-loop patch element being spaced from each of said x and y conductive elements of said square grid with a spacing G, and said x and y conductive elements of each square of said square grid have a width W1 =0.0205λ
Specification
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- Resources
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Current AssigneeUnited States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
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Original AssigneeUnited States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
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InventorsWu, Te-Kao
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Primary Examiner(s)Lee, Benny T.
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Application NumberUS08/094,331Time in Patent Office964 DaysField of Search343/909, 343/754, 343/753, 333/134, 333/202US Class Current343/909CPC Class CodesH01Q 15/0033 used for beam splitting or ...
