A switched beam single arm rectangular spiral antenna with hybrid switch network

A single-arm rectangular spiral antenna with a hybrid (short and open) switch network is proposed for switched beam applications. The excitation of switches in the hybrid network introduces variation in the current distribution on the antenna arm, thus causing the beam to steer into various directions. A shorting switch is implemented as an element to short-circuit a point on the spiral arm to the ground conductor and an opening switch is implemented as an element to split open the spiral arm. A hybrid spiral configuration using four switches (two short and two open) is analysed with both single- and multi-point switching. Sixteen possible switching cases are investigated. Using the different switching cases, the beams are obtained in various directions, thus realizing a switched beam antenna. The gain stays uniform within ± 1 dB variation around 6.5 dBi and the VSWR remains within the acceptable limit for majority of the switching cases.