Apple Inc.

Dominic Koehler

Rastislav Vazny

Harald Pretl

Christof Pfannenmüller

Oliver Georg Dorn

Bjoern Lenhart

Christian F Tanzer

Julian W Zuber

Joonhoi Hur

A differential double balanced duplexer (dDBD) includes a transmitter and a first balun are coupled to a first impedance tuner that produces a first impedance that blocks received signals at a first frequency range from travelling across the first balun and into the transmitter, and a second impedance that passes transmitted signals at a second frequency range to travel across the first balun to the antenna. The dDBD also includes a receiver and a second balun coupled to a second impedance tuner that produces a first impedance that allows the received signals at the first frequency range to travel across the second balun and into the receiver, and a second impedance that blocks the transmitted signals at the second frequency range from travelling across the second balun and into the receiver. As such, the dDBD allows for increased isolation and decreased insertion loss.

Differential double balanced duplexer

An electronic device may include isolation circuitry coupled between a transmitter, a receiver, and one or more antennas. The isolation circuitry may include a 90 degree hybrid coupler configured receive a transmission (TX) signal from the transmitter, split the TX signal into a first portion and a second portion, and phase-shift a portion such that the portions are +90 degrees out-of-phase. The isolation circuitry may include phase shifters that phase-shift the portions such that the portions are in-phase prior to propagating to the antenna. The phase shifters may receive a first portion and a second portion of a receiver (RX) signal from splitter circuitry. The phase shifters may phase-shift the portions such that the portions are out-of-phase by −90 degrees. The 90 degree hybrid coupler may phase-shift the first portion and/or the second portion such that the portions are in-phase and constructively combine prior to propagating to the receiver.

Duplexer architecture using 90 degree hybrid coupler based balancing conditions

Systems and methods combine a test signal with a wanted (downlink or uplink) signal at an input of a duplexer of a communication device, and receive the test signal at an output of the duplexer. The test signal may include a radio frequency signal having less power than the wanted signal to avoid interference, or a digital signal that is added to or extracted from the wanted signal when the wanted signal does not have a radio frequency. A processor of the communication device causes the duplexer to operate in a tuning state (e.g., to transmit signals having a transmission frequency and receive signals having a receive frequency). The measurement system determines a difference or ratio in power between the test signal at the duplexer output and the duplexer input, and adjusts the tuning state based on the difference or ratio (e.g., to decrease or minimize the difference or ratio).

Duplexer measurement and tuning systems

Growing community of inventors

Viereth-Trunstadt, Germany

Dominic Koehler