Polarization improvement through sinuous antenna arm modification

The arms of a sinuous antenna are modified and the effects are investigated in terms of the polarization and group delay. Conventional sinuous antennas (CSA's) operate over a broad bandwidth. However, they show unwanted spikes when their polarization and group delay are plotted as functions of frequency. These spikes are thought to originate from the sharp ends and the bends of the arms. This paper shows that the spikes can be suppressed significantly by removing the sharp ends and the bends of the arms.