Generalized dielectric resonator filter

• US 4,477,785 A
• Filed: 12/02/1981
• Issued: 10/16/1984
• Est. Priority Date: 12/02/1981
• Status: Expired due to Term

• Current Assignee: COMSAT Corporation (Reorganized ISA SA)
• Original Assignee: Communications Satellite Corporation (Reorganized ISA SA)
• Inventors: Atia, Ali E.
• Primary Examiner(s): Nussbaum, Marvin L.
• Application Number:
  US06/326,643
• Time in Patent Office: 1,049 Days
• Field of Search: 333/202-208, 333/212, 333/219, 333/227-235
• US Class Current: 333/202
• CPC Class Codes: H01P 1/2084 with dielectric resonators

Abstract

A generalized dielectric resonator filter is disclosed for the realization of the most general transfer function characteristics of band-pass filters using cylindrical dielectric resonator discs in a microstrip transmission line configuration. The dielectric resonator filter of the invention has electrical properties comparable to conventional waveguide filters, but has a much smaller volume and mass, and is thus very attractive for use in the construction of input multiplexers of communications satellite transponders.

Claims

1. A generalized canonical form filter for electromagnetic waves, comprising an input, an output and a plurality of dielectric resonators disposed between said input and said output, said resonators being serially coupled by series couplings of the same sign, physically adjacent but electrically non-adjacent resonators being coupled by shunt couplings of arbitrary sign, wherein said couplings comprise microstrip lines extending between said resonators, said lines terminating in arcuate portion having a radius originating at the centers of said resonators.

2. A filter as claimed in claim 1, wherein said electrically non-adjacent resonators are separated by a central wall, and are coupled by means of λ

/4 or 3λ

/4 length microstrip lines running between said resonators and beneath said central wall.

3. A filter as claimed in claim 1 or 2, wherein said resonators are disposed in two adjacent rows, and within each row said series couplings comprise microstrip lines disposed on a substrate, said resonators being separated by partial walls and said series couplings running beneath said partial walls.

4. A filter as claimed in claim 1 or 2, wherein said resonators are disposed in two adjacent rows, and within each row said series couplings comprising directly coupled resonators.

5. A filter as claimed in claim 1, wherein said resonators are disposed above said microstrip coupling lines by a distance, the value of said couplings being adjustable primarily by varying said distance.

6. A filter as claimed in claim 5, said resonators being supported by dielectric spacers.

7. A filter as claimed in claim 5, said resonators being supported by foam support members.

8. A filter as claimed in claim 1, said filter being disposed within a housing having a central wall separating adjacent rows of resonators, at least said shunt couplings comprising microstrip lines between resonators, said microstrip lines being disposed on a substrate covered by said housing, said resonators being spaced from said substrate.