Abstract: A time division duplex (TDD) wireless apparatus includes a low noise amplifier (LNA) system, at least one antenna and a transceiver system. The apparatus supports N time division duplexed channels which each have a transmit direction of transmission flow and a receive direction of transmission flow. The LNA system comprises N sub-units. Each sub-unit comprises 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. The first circulator and second circulator within each sub-unit are interconnected to provide a path in one of the directions of transmission flow. 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. A single channel variant is also provided.

Abstract: A time division duplex (TDD) wireless apparatus includes a low noise amplifier (LNA) system, at least one antenna and a transceiver system. The apparatus supports N time division duplexed channels which each have a transmit direction of transmission flow and a receive direction of transmission flow. The LNA system comprises N sub-units. Each sub-unit comprises 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. The first circulator and second circulator within each sub-unit are interconnected to provide a path in one of the directions of transmission flow. 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. A single channel variant is also provided.

Abstract: A power efficient system and method for linear signal power amplification are provided. A linear power amplifier provides signal amplification from a system input to a system output and is drain-modulated with a power supply signal. An active compensation circuit generates the power supply signal, which is substantially proportional to an envelope of the system input, and provides it to the power amplifier through a low-impedance output. The active compensation circuit reduces noise in the system output spectrum.

Abstract: A pulse width modulated (PWM) power supply has a plurality of phases. Each phase comprises a power switching device for generating an output signal. A controller receives a modulating input signal and generates a set of control signals, each control signal controlling the operation of the switching device in a respective one of the phases. Each control signal comprises a sequence of time windows, with a pulse of variable width positioned within each time window. Control signals for some of the phases are aligned to different parts of their respective time windows compared to the control signals for other phases. This has been found to improve linearity when operating at extremes of normal operating range.