Coupled‐sectorial‐loop antenna with circular sectors for super wideband applications

A coupled-sectorial-loop antenna (CSLA) with circular sectors is presented for super wideband (SWB) applications. Conventional CSLA consists of two parallel sectorial loop antennas connected along an axis of symmetry and triangular sectors are used. The average input impedance of the conventional CSLA is over 100 Ω, and a half of the CSLA above a ground plane is used to match with a 50-Ω feed line. In the proposed antenna, circular sectors are used instead of triangular sectors to directly match with the 50-Ω feed line, and the full structure of the CSLA is used. A prototype of the proposed antenna is fabricated on an FR4 substrate, and its performance is compared to the conventional CSLA. The experimental results show that the frequency band for a voltage standing wave ratio < 2.15 is 1.0–19.4 GHz (180.4%), which satisfies the requirement of the SWB antenna. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1683–1689, 2014