Space filter surface

• US 4,126,866 A
• Filed: 05/17/1977
• Issued: 11/21/1978
• Est. Priority Date: 05/17/1977
• Status: Expired due to Term

• Current Assignee: The Ohio State University Research Foundation
• Original Assignee: The Ohio State University Research Foundation
• Inventors: Pelton, Edward L.
• Primary Examiner(s): Smith, Alfred E.
• Assistant Examiner(s): Moore, David K.
• Application Number:
  US05/797,797
• Time in Patent Office: 553 Days
• Field of Search: 343/754, 343/767, 343/770, 343/771, 343/909, 343/872, 343/18 A, 343/18 B
• US Class Current: 343/909
• CPC Class Codes: H01Q 1/281 Nose antennas
• CPC Class Codes: H01Q 1/425 comprising a metallic grid
• CPC Class Codes: H01Q 15/0013 said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective

Abstract

A surface used as a space filter in electromagnetic space. The filter surface is formed as a periodic array of recurrent filter components clustered in groups of three each incorporating pairs of elements extending outwardly at an internal angle of 120°. A reactive load present as a U-shaped loop is coupled with the terminal portions of each element and extends outwardly therebetween.

Claims

1. In a space filter of a variety incorporating a surface disposed array of recurrent filter components mutually arranged in a periodic pattern, the improvement comprising:

a surface incorporating a cluster of three discrete mutually spaced filter components, each said component comprising a pair of thin elements each extending from a terminal portion thereof to define linear portions, said linear portions being symmetrically disposed about, and at an angle of about 60°

, with respect to an axis bisecting them;

means defining a reactive load connected with each said terminal portion and configured as a loop symmetrically disposed about said axis and extending outwardly between said linear portions; and

the said axis of any given one of said three filter components being disposed with respect to an adjacent other one of said axes at an angle of about 60°

whereby said filter components within said cluster are mutually symmetrically disposed; and

the adjacent linear portions of said three filter components being mutually spaced and defining an open ended surface region whereby all portions of said surface are present in the array and in a continuous fashion.

2. The improved filter component of claim 1 wherein a said element is configured having an outward portion integral with and extending from said linear portion a predetermined distance to a terminus and mutually oppositely disposed at an internal angle greater than said 60°

.

3. The improved filter component of claim 1 in which said recurrent filter components are present as slots within a conductive surface to provide a band-pass function.

4. The improved filter component of claim 1 in which said recurrent filter components are present as conductive dipole elements to provide a band stop function.

5. The improved filter component of claim 1 in which said means defining a reactive load loop configuration is geometrically shaped as a, U, one termini of each side of which is coupled to a corresponding said element terminal portion;

and

each said element is configured having an outward portion extending from said linear portion a predetermined distance to a terminus and in paralleled relationship with an adjacent said U side.

6. The improved filter component of claim 1 wherein each said element is configured having an outward portion integral with and extending from said linear portion a predetermined distance and disposed in parallel relationship with said bisecting axis.

7. The improved filter component of claim 6 in which said outward portion predetermined distance is less than the length of an associated said linear portion.

8. A space filter comprising:

a periodic array of recurrent filter components present as slots within a conductive surface, each said filter component including;

a pair of thin, elongate elements each extending from a terminal portion thereof to define linear portions said linear portions being symmetrically disposed about, and at an angle of about 60°

, with respect to an axis bisecting them;

means defining a capacitive, reactive load formed as a slot within said conductive surface and connected with each said terminal portion of the said linear portions of a said pair of elements and extending outwardly in the form of a loop symmetrically disposed about said axis; and

said filter components being positioned within said array in recurring clusters of three discrete components arranged symmetrically in close mutual adjacency, the said axis of any given one of said three filter components being disposed with respect to an adjacent other one of said axes at an angle of about 60°

, the adjacent linear portions of said three filter components being mutually spaced and defining an open ended surface region whereby all portions of said conductive surface are present within said array in continuous integrally associated fashion.

9. The space filter of claim 8 wherein each said element is configured having an outward portion integral with and extending from said linear portion a predetermined distance to a terminus and mutually oppositely disposed at an internal angle greater than 60°

.

10. The space filter of claim 8 in which the distance between adjacent rows of said recurring clusters of filter components within said periodic array is less than one half the wavelength of the resonant frequency selected for filter performance.

11. The space filter of claim 8 in which:

each said element is configured having an outward portion integral with and extending from said linear portion a predetermined distance to a terminus and mutually oppositely disposed at an internal angle greater than 60°

, and

the distance between adjacent rows of said recurring clusters of filter components within said periodic array is less than one half the wavelength of the resonant frequency selected for filter performance.

12. The improved filter component of claim 8 wherein each said element is configured having an outward portion integral with and extending from said linear portion a predetermined distance and disposed in parallel relationship with said bisecting axis.

13. The improved filter component of claim 8 in which said outward portion predetermined distance is less than the length of an associated said linear portion.