Multiplexers and Duplexers Having Active Cancellation for Improved Isolation between Transmit and Receive Ports

• US 20160094331A1
• Filed: 09/26/2014
• Published: 03/31/2016
• Est. Priority Date: 09/26/2014
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP (Singapore) PTE Limited (Broadcom, Inc.)
• Inventors: White, Christopher, Bradley, Paul D.
• Application Number:
  US14/498,875
• Publication Number:
  US 20160094331A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03F 1/02 Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 2001/045 with means for improving efficiency
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

A multiplexer is configured to receive a transmit signal from a first amplifier and to provide a receive signal to a second amplifier. A leakage signal is transmitted to a path leading to the second amplifier. A first device configured to provide a portion of the transmit signal to an active cancellation circuit, the active cancellation circuit configured to substantially invert the phase of the portion of transmit signal and to attenuate the amplitude of the portion of the transmit signal. A second device configured to receive the portion of the transmit signal from the active cancellation circuit, and to combine the portion of the transmit signal from the active cancellation circuit with the leakage signal prior to an input to the second amplifier.

Claims