Balanced active and passive duplexers

• US 20070015468A1
• Filed: 04/13/2006
• Published: 01/18/2007
• Est. Priority Date: 04/14/2005
• Status: Active Grant

• Current Assignee: Ecole de technologie superieure
• Original Assignee: Ecole de technologie superieure
• Inventors: Kouki, Ammar, Talbot, Christian
• Granted Patent: US 8,364,092 B2
• Time in Patent Office: Days
• US Class Current: 455/63.100
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver

Abstract

An active cancellation unit is disclosed for improving the noise cancellation between a transmitter and a receiver which are connected to an antenna using a duplexer, the unit comprising a coupler sampling a signal to transmit provided by the transmitter, a cancellation duplexer having characteristics similar to the duplexer and receiving the sampled signal to provide a simulated signal and an active component receiving the simulated signal and providing an amplified signal having a phase 180 degree shifted with respect to the simulated signal; and a coupler for injecting the simulated signal at the receiver.

Claims

1. An active cancellation unit for improving the noise cancellation between a transmitter and a receiver which are connected to an antenna using a duplexer, said unit comprising:

a coupler sampling a signal to transmit provided by the transmitter;

a cancellation duplexer having characteristics similar to the duplexer and receiving the sampled signal to provide a simulated signal;

an active component receiving the simulated signal and providing an amplified signal having a phase 180 degree shifted with respect to the simulated signal; and

a coupler for injecting said simulated signal at the receiver.

2. The active cancellation unit as claimed in claim 1, wherein said cancellation duplexer comprises a filter-based duplexer.

3. The active cancellation unit as claimed in claim 2, further comprising an impedance tuner operatively connected to the filter-based duplexer.

4. The active cancellation unit as claimed in claim 1, wherein said cancellation duplexer comprises a circulator-based duplexer.

5. The active cancellation unit as claimed in claim 4, further comprising an impedance tuner operatively connected to the circulator-based duplexer.

6. The active cancellation unit as claimed in claim 1, wherein said transmitter and said receiver are connected to said antenna using a duplexer selected from a group comprising filter-based duplexers and circulator-based duplexers.

7. The active cancellation unit as claimed in claim 1, wherein said active component comprises a variable attenuator for receiving said simulated signal and for providing an attenuated signal, a phase shifter for receiving said attenuated signal and for providing a signal having a phase 180 degree shifted and an amplifier for receiving said signal having a phase 180 degree shifted and for providing said amplified signal having a phase 180 degree shifted.