UWB coplanar waveguide‐fed coplanar strips rectangular spiral antenna

This article proposes an ultra-wideband coplanar strips (CPS) rectangular spiral antenna that is fed by coplanar waveguide (CPW). The CPS is formed by gradually reducing the width of the CPW ground planes without the need of a balun. The antenna operates in the frequency band (3.5-10.6 GHz) and has miniaturized size of 50 × 40 × 0.508 mm on a Rogers RO4003C substrate. The CPS spiral is terminated with a 100 Ω chip resistor for matching. A parametric study was performed to choose the CPS spiral dimensions. A good agreement is found between simulations and measurements in the radiation pattern and the return loss which was found to be better than 10 dB over the band. The measured peak gain ranges between 1 and 4.7 dBi.