Wideband Microstrip Fed Slot Antenna Featuring Mode Conversion and Coordinated Radiation

Wireless communication systems need broadband antennas with small backward radiation antennas for large throughput and low interference. This letter presents the design of a microstrip fed slot wideband antenna featuring mode conversion between heterogeneous transmission lines and coordinated radiation of multiple slots, which ensure the antenna achieve an average gain of 5.17 dBi in a bandwidth ranging from 0.75 to 2.24 GHz. Aiming at reducing backward radiation, electro‐magnetic wave is redirected to the upper hemisphere through four rectangular slots that were placed in the ground plane. Measured results show the antenna's max gain of 6.12 dBi and a variation of ±0.95 dB in a fraction bandwidth of 99.7%, which verifies the design as they agree well with the simulated ones. The average gain increment from original antenna to proposed antenna is 8.6 dB and the average backward radiation reduction from original antenna to proposed antenna is 16.03 dB. The wide bandwidth, small backward radiation and gain variation make the antenna suitable for wideband communication systems.