Ultra wideband power divider design implementing microstrip with slotted ground

Abstract

This article proposes a compact design of a two-section power divider, which operates over an ultra wideband frequency range of 3-11 GHz. The design approach of microtrip with slotline at the ground plane is applied to reduce the size of the circuit and to achieve wide bandwidth coverage. The rectangular slots are implemented at the ground plane, which is positioned symmetrically underneath the second and third arms of each microstrip quarter-wave transformer to reduce its length up to 33.34%. These attributes lead to an easily fabricated 20 mm x 23 mm compact power divider with a reduced size (by 23.33%). The bandwidth performance is improved up to 19.4% compared to a conventional divider. The design is realized by implementing the Rogers TMM4 substrate and simulated by using CST Microwave Studio. The power divider is verified by using a vector network analyzer (VNA). A good agreement between simulation and fabrication is achieved in terms of return loss, isolation and transmission coefficients across the UWB frequency range.