Systems, devices and methods are provided to switch between transmit and
receive modes in wireless hearing aids. One aspect relates to an
apparatus for use within a communication system that has an inductive
coil connected to a tuning capacitor at a node. An amplifier is connected
to the node through a DC blocking capacitor to receive an induced signal
in the inductive coil in a receive mode. A driver energizes the inductive
coil with a driven signal in a transmit mode. According to various
embodiments, the apparatus transforms the inductive coil, the tuning
capacitor and the DC blocking capacitor into an equivalent series
resonant circuit to reduce an inductive load in the transmit mode, and
transforms the inductive coil, the tuning capacitor and the DC blocking
capacitor into an equivalent parallel resonant circuit to increase an
inductive load in the receive mode.