Patent ID: 7616940

Claim:
A low noise amplifier (LNA) system for a time division duplex (TDD) wireless apparatus, the wireless apparatus comprising at least one antenna and a transceiver system and supporting N time division duplexed channels which each have a transmit direction of transmission flow and a receive direction of transmission flow, the LNA system comprising: N sub-units, each sub-unit comprising a first circulator for connecting to a respective TX/RX feed to the transceiver system and a second circulator for connecting to the at least one antenna; wherein the first circulator and second circulator within each sub-unit are interconnected to provide a path in one of the directions of transmission flow and the first circulator of each sub-unit is connected to the second circulator of another sub-unit to provide a path in the other direction of transmission flow, there being N paths in each direction of transmission flow in total, and wherein the paths which provide the receive direction of transmission flow comprise a low noise amplifier.