Ultra-wideband non-reflecting planar spiral slot antenna using post-wall structure

An ultra-wideband non-reflecting antenna is proposed and is demonstrated and verified by a post-wall coplanar stripline (CPS) based spiral slot antenna. The post-wall coplanar stripline, composed of a bilateral CPS and two metalized via arrays aligned at the slot edges, is used for constructing the spiral slot antenna. Due to the lower available characteristic impedance and larger variation range of post-wall CPS, the proposed spiral slot can be fed directly by coaxial SMA connector and terminated easily by resistive loads. Consequently, traveling wave is formed on the proposed antenna and the energy is radiated when electromagnetic wave transmitting along the spiral slot, but no reflection is produced. The simulated and measured results verify the ultra-wideband non-reflecting antenna concept and demonstrate the feature of the post-wall structure based spiral slot antenna.