TRACKING ANTENNA SYSTEM

摘要

An antenna system comprising a first antenna cell and at least one other antenna cell. Each antenna cell comprises a respective antenna element and generates, in use, a respective output signal from an input signal received during use. The other antenna cells include a phase locked loop (PLL) circuit for tracking changes in the phase of the received input signal. The PLL circuit includes an input for receiving a phase reference signal, the input being connected to the output of the first antenna cell to receive the output signal of said first antenna cell as its phase reference signal. The use of the phase modulated output signal as the reference input for the PLL allows the PLL to track phase changes as a result of relative movement between a source and a receiver, and to compensate for phase differences caused by the spacing between the respective antenna elements of the phased array.