Apple Inc.
SINGLE LADDER DUPLEXER WITH IMPEDANCE GRADIENT

Abstract:

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.