Patent ID: 8295212
Filing Date: 2012-10-23
Classification: H03F,H04B

Abstract:
1. A time division duplex circuit for connecting a transceiver input/output (I/O) to an antenna, comprising: a forward transmission path structure, providing a forward directional signal transmission path extending from a given radio frequency (RF) transmitter feed to a given antenna feed; a first hybrid coupler, having a first port connected by a first rearward transmission path structure to the antenna feed; a second hybrid coupler having a first port connected by a second rearward transmission path structure to an input of a given RF receiver; a first RF amplifier, having an input connected by a first switchable impedance connector to a second port of the first hybrid coupler, and having an output connected by a second switchable impedance connector to a second port of the second hybrid coupler; a second RF amplifier, having an input connected by a third switchable impedance connector to the third port of the first hybrid coupler, and having an output connected by a fourth switchable impedance connector to a third port of the second hybrid coupler; a third hybrid coupler, having a first port connected to a fourth port of the second hybrid coupler, and having a second port connected to the fourth port of the first hybrid connector, a third port terminated by a first switchable impedance termination device, and a fourth port terminated by a second switchable impedance termination device; wherein each of said switchable impedance connectors is configured to switch its impedance between a given matching impedance and a given mismatching impedance, in response to a given condition, wherein each of said switchable impedance terminations is configured to switch its impedance between a given matching impedance and a given mismatching impedance, in response to a given condition, and wherein said first hybrid coupler, second hybrid coupler and third hybrid coupler are arranged and configured to provide, in response to a concurrence of said switchable impedance connectors and said switchable impedance terminations having the mismatching impedance, a bypass rearward directional path from the first port of the first hybrid coupler to the first port of the second hybrid device, said bypass rearward directional path bypassing said first and second RF amplifiers.