Modified end-fire bow-tie antenna fed by microstrip line for wideband communication systems

摘要

A broadband microstrip-fed modified printed bow-tie antenna is proposed. Using a rounded ground plane, adding a pair of circular patches to the bow-tie arms, and optimizing the design parameters, an operation frequency band of 3.3-15.2 GHz is achieved. The development stages of the modified bow-tie radiator is exhibited and it is shown that by designing different antenna structures, the impedance bandwidth (defined by -10-dB reflection coefficient) can be improved from 37% to more than 128%. The modified antenna possesses advantages of not only a broad bandwidth of 128%, but also a small size of 34 × 34 × 1.2 mm~3. The designed antenna was fabricated and tested. The impedance matching, group delay, and the antenna radiation characteristics, including co-polarized far-field patterns, cross-polarized patterns, radiation efficiency, and gain were analyzed with numerical simulation and experimental measurement. Measured data are in good agreement with the simulated results. Based on the obtained frequency- and time-domain characteristics, the designed antenna is an attractive candidate for broadband communication applications.