Multiple output RF filter and waveguide

• US 5,656,980 A
• Filed: 02/08/1996
• Issued: 08/12/1997
• Est. Priority Date: 09/27/1994
• Status: Expired due to Term

• Current Assignee: Harris Stratex Networks, Inc.
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Zimmerman, Eric J.
• Primary Examiner(s): Lee, Benny
• Assistant Examiner(s): VU, DAVID HUNG
• Application Number:
  US08/598,404
• Time in Patent Office: 551 Days
• Field of Search: 333/212, 333/206, 333/207, 333/208, 333/204, 333/209, 333/227, 333/228, 333/230, 333/231, 333/246, 333/126, 333/128, 333/134, 333/135, 333/137, 333/123, 333/248
• US Class Current: 333/208
• CPC Class Codes: H01P 1/208 Cascaded cavities; Cascaded resonators inside a hollow waveguide structure H01P1/205 takes precedence

Abstract

A multiple output filter coupler for providing plural RF output signals from a single RF input signal may include an RF waveguide filter for receiving an RF input signal at one end thereof and for filtering the received RF input signal along its length, and plural connectors attached to the waveguide filter'"'"'s end cavity for providing plural filtered RF output signals. Tuners attached to the waveguide filter proximate the connectors may be used to vary the relative signal strengths of the filtered RF output signals. The filter coupler'"'"'s output and input may be interchanged to provide a single output from multiple inputs.

Claims

1. An integrated filter coupler for connecting two radio frequency (RF) signals to a single RF signal, the two RF signals being copies of the single RF signal, comprising:

a hollow waveguide having first and second ends;

a first coupler connector at said first end of said waveguide for the single RF signal;

a first tuner inserted into said waveguide first end a selectable distance for tuning the single RF signal at said first connector;

second coupler connectors with extensions inserted into said waveguide at said second end which is free of partitions between said extensions of said second connectors into said second end, each of said connectors for providing one of the two RF signals which are copies of the single RF signal; and

second tuners inserted into said waveguide second end a selectable distance, each of said second tuners for tuning the RF signal at one of said second connectors, and for selectably varying the signal strength of the RF signal at one said second connector relative to the signal strength of the RF signal at the other said second connector.

2. The coupler of claim 1 wherein said first and second ends of said waveguide are closed with first and second end plates.

3. The coupler of claim 2 wherein said first tuner is extend through said first end plate, and at least one of said second tuners is extended through said second end plate.

4. The coupler of claim 1 wherein said first and second ends of said waveguide comprise respective end cavities separated from the remainder of said hollow waveguide interior with posts extending laterally therethrough.

5. The coupler of claim 1 wherein said waveguide further comprises plural tunable cavities for filtering the RF input signal.

6. The coupler of claim 1 wherein said waveguide has an interior with a generally rectangular vertical cross section of a size suitable for operation with radio frequencies of at least a gigahertz.

7. The coupler of claim 1 wherein said first and second connectors are SMA connectors.

8. A method of providing two filtered radio frequency (RF) output signals of selectable signal strength which are filtered copies of a single RF input signal received on an antenna, comprising the steps of:

providing the RF input signal from the antenna to a hollow waveguide filter at an opening at a first end thereof;

filtering the RF input signal with plural tunable cavities interior to the waveguide filter;

providing each of the two filtered RF output signals from a different one of two output connectors inserted into an end cavity of the waveguide filter perpendicular to an axis of the waveguide filter at a second end thereof which is free of partitions between the inserted connectors, each connector providing an RF output signal which is a filtered copy of the RF input signal to one of the radio receivers; and

selectably varying the signal strength of the filtered RF output signals with two tuning adjusters inserted into the second end of the waveguide filter perpendicular to a corresponding one of the output connectors, each of the tuning adjusters being positioned at a selectable distance into the waveguide filter into proximity with the corresponding one of the output connectors,

whereby the signal strength of one RF output signal for one radio receiver may be varied relative to the signal strength of the other RF output signal for the other radio receiver.

9. A multiple output filter coupler for providing plural filtered RF output signals of selectable relative signal strengths from a single RF input signal, said filter coupler comprising:

a RF waveguide filter for receiving an RF input signal at one end thereof and for filtering the received RF input signal along its length;

plural connectors, each for providing one of the plural filtered RF output signals and each with an extension extending into a second end of said waveguide filter perpendicular to an axis of said waveguide filter at the second end, said second end being free of partitions between said extensions of said plural connectors so that the filtered RF output signals have the same frequencies; and

plural signal strength adjusters, each for being inserted into said second end perpendicular to, and at a selectable distance from, a different one of said extensions to selectively vary the relative signal strengths of the filtered RF output signals from said connectors.

10. The filter coupler of claim 9 wherein at least one of said plural signal strength adjusters is inserted through a wall of said waveguide filter.

11. The filter coupler of claim 9 wherein at least one of said plural signal strength adjusters is inserted through an end plate closing said second end.

12. The filter coupler of claim 9 wherein said waveguide filter comprises plural compartments along its length, each of said compartments having a device therein for tuning a frequency response of said waveguide filter.

13. The filter coupler of claim 12 wherein said tunable compartments are tuned by devices inserted into said tunable compartments a selectable distance through apertures in sides of said waveguide filter.

14. The filter coupler of claim 9 wherein the RF input signal is a microwave signal.