Reconfigurable diplexer for communications applications

• US 20010035801A1
• Filed: 03/15/2001
• Published: 11/01/2001
• Est. Priority Date: 03/17/2000
• Status: Active Grant

• Current Assignee: Achilles Technology Management Co Ii, Inc.
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: Gilbert, Roland A.
• Granted Patent: US 6,373,349 B2
• Time in Patent Office: Days
• US Class Current: 333/126
• CPC Class Codes: H04B 1/52 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa

Abstract

The present invention provides a reconfigurable diplexer which is well suited for use with mulitple element antenna arrays. The diplexer includes a common, slot-line transmission line adapted to carry electromagnetic signals; a pair a separate slot-line transmission lines coupled to the common transmission line; each separate slot-line transmission line having an individual filter coupled thereto, wherein each filter is adapted to selectively give its respective separate slot-line transmission line a characteristic impedance dependent upon predetermined frequencies of the electromagnetic signals; and a separate slot-line balun associated with each separate slot-line transmission line and adapted for coupling signals to and/or from its respective separate slot-line transmission line. The diplexer may be configured to operate in several different bands such as the INTELSAT frequencies (7.2-8.4 GHz) or DSCS frequencies (11.7-14.5 GHz).

Claims

1. A diplexer for coupling transmission signals to and from a single transmission line, comprising:

a common, slot-line transmission line adapted to carry electromagnetic signals;

a pair a separate slot-line transmission lines coupled to the common transmission line;

each separate slot-line transmission line having an individual filter coupled thereto, wherein each filter is adapted to selectively give its respective separate slot-line transmission line a characteristic impedance dependent upon predetermined frequencies of the electromagnetic signals; and

a separate slot-line balun associated with each separate slot line transmission line and adapted for coupling signals to and/or from its respective separate slot-line transmission line.

2. The diplexer of

claim 1

, wherein each individual filter includes one or more tunable resonant slot-line cavities.

3. The diplexer of

claim 2

, wherein the resonant slot-line cavities are individually tunable by one or more separate switches at predetermined locations along the resonant slot-line cavities and selectively connectable across the respective cavities to determine the electrical length of the respective cavities.

4. The diplexer of

claim 3

, wherein the separate slot-line transmission lines are each coupled to the common slot-line transmission line at a respective coupling point and further wherein the electrical length of the respective cavities is determined with reference to the respective coupling points.

5. The diplexer of

claim 2

, wherein each individual filter includes a multiplicity of resonant slot-line cavities which each affect the characteristic impedance of the respective separate slot-line transmission line incrementally over a limited bandwidth and collectively over a combined broader bandwidth.

6. The diplexer of

claim 1

, wherein the common slot-line transmission line is adapted for coupling to an antenna element and further wherein the separate slot-line transmission lines are adapted to function as transmit and receive transmission lines, respectively.

7. The diplexer of

claim 6

, wherein said diplexer is adapted for satellite communication service and coupling an uplink frequency over the transmit transmission line and a downlink frequency over the receive transmission line.

8. The diplexer of

claim 7

, wherein said diplexer is adapted for selectable service in at least the defined INTELSAT and DSCS frequency bands.

9. The diplexer of

claim 8

, wherein said uplink frequency lies in one of the frequency bands:

7.8-8.4 GHz and 13.5-14.5 GHz, and said diplexer is electrically switchable therebetween.

10. The diplexer of

claim 9

, wherein said downlink frequency lies in one of the frequency bands:

7.2-7.6 GHz and 11.7-12.5 GHz, and said diplexer is electrically switchable therebetween.

11. The diplexer of

claim 7

, wherein said diplexer is adapted to maintain approximately a 50 dB channel separation between signals in transmit and receive transmission lines.