Apple Inc.

Oliver Georg Dorn

Rastislav Vazny

Joonhoi Hur

Björn Lenhart

Harald Pretl

Christof Pfannenmüller

Dominic Koehler

Julian W Zuber

Bjoern Lenhart

Christian F Tanzer

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

Embodiments presented herein relate to isolating a receiver circuit of an electronic device from a transmission signal and from a noise signal at a frequency range of a received signal. To do so, an isolation circuit is disposed between the receiver circuit and a transmission circuit. The isolation circuit may include multiple variable impedance devices and one or more antennas. The impedances of the variable impedance devices and the one or more antennas may be balanced such that the receiver circuit is effectively removed from the transceiver circuitry and isolated from the transmission signal. The impedance of the variable impedance devices and the one or more antennas may also be configured to isolate the receiver circuit from a noise signal generated at the transmission circuit having a frequency in the range of the receive signal.

Single ladder duplexer with impedance gradient

An electrical balance duplexer has multiple impedance gradients and multiple impedance tuners. The electrical balance duplexer transmits an outgoing signal from a transmitter during a transmission mode when a first set of impedance gradients of the multiple impedance gradients is operating in a first impedance state and a first set of impedance tuners of the multiple impedance tuners is operating in a second state. The electrical balance duplexer isolates the outgoing signal from a receiver during the transmission mode when a second set of impedance gradients of the multiple impedance gradients and a second set of impedance tuners of the multiple impedance tuners are operating in the second impedance state.

Duplexer with balanced impedance ladder

Embodiments disclosed herein relate to reducing or substantially eliminating an insertion loss caused by isolating a transmit circuit from a receive circuit of an electronic device. To do so, an isolation circuit may be disposed between the transmit circuit and the receive circuit. The isolation circuit may have a first signal path and a second signal path. A first portion of the signal may propagate along the first signal path and a second portion of the signal may propagate along the second signal path. A phase shifter may be disposed on the first signal path to shift a phase of the first portion to match a phase of the second portion. The phase-shifted first portion may be combined with the second portion to reduce or substantially eliminate an insertion loss caused by the isolation circuit.

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Erlangen, Germany

Oliver Georg Dorn