Substrate Integrated Coaxial Line Excited Wideband Millimeter Wave Bow-Tie Antenna

This paper describes the design of a new excitation technique known as the Substrate Integrated Coaxial Line (SICL) technology for bow tie antenna operating in Millimeter wave (MM-wave) frequency. Substrate Integrated Coaxial Line provides wide bandwidth for TEM mode of operation. The Bow Tie antenna excited by SICL exhibits a wide 10 dB impedance bandwidth of 8.7 GHz with an average gain of 4.5 dBi in the entire frequency band. One advantage of using this new feeding technique is the elimination of balun as required in the microstrip technology to feed the antenna. Another advantage is the wideband nature of SICL that is difficult to be obtained with its counterpart namely, SIW (Substrate Integrated Waveguide). The end-fire radiation pattern of the proposed antenna shows co-polarization to cross polarization ratio of 13.7 dB at the center frequency. The antenna is suitable for 5G applications at millimeter wave frequencies beyond 24 GHz and applications at LMDS band.