Design of a reconfigurable RF network for polarization-agile antenna applications

In this paper, a reconfigurable RF network for polarization-agile antenna applications is presented. This network consists of a two-way reconfigurable Wilkinson power divider and two reconfigurable phase shifters (45°/135°). By controlling the bias voltage of the PIN diodes, two kinds of single-path transmission modes (1:0 and 0:1) and three kinds of two-path transmission modes (1:1, 1:j and j:1), namely, five different transmission modes in total can be realized. The measured results show that the insertion losses are less than 1.5 dB, and the return losses of the input port are all higher than 12.1 dB when the reconfigurable RF network operates in single-path mode with a relative bandwidth of 6.7%. For the two-path mode with a relative bandwidth of 4.3%, the isolations between two output ports are higher than 23.6 dB, and the phase differences are 3.5-5.4° (1:1 mode) and 92.6-97.4° (1:j mode and j:1 mode), with phase error less than 7.4°.