Small ferrite‐loaded four‐petal‐shaped substrate integrated waveguide antenna with enhanced bandwidth

Abstract

A ferrite‐loaded four‐petal‐shaped antenna with enhanced bandwidth is designed and fabricated. There are two layers in the antenna. A substrate integrated waveguide cavity is formed by a circular metallized via array on the lower substrate of the antenna. As a broadband radiating element, a four‐petal‐shaped radiation unit is etched on the bottom surface of the circular SIW cavity. By loading low‐loss ferrite discs with relatively high dielectric constant in the upper substrate layer as dielectric resonators, a relatively smaller broadband cross‐dipole antenna is realized. The measured results demonstrate that the working frequency band of the antenna is 1.83 to 3.53 GHz (63.4%) if the S11 is less than ‐10 dB. The antenna with the size of 0.29λmax × 0.29λmax has stable bidirectional radiation patterns with the average realized gain and radiation efficiency of 4.14 dBi and 94% in the working frequency range. Due to the characteristics of low cost, low profile, easy integration with planar circuit, the proposed antenna is suitable for wireless communication applications, such as CDMA, 4G, 5G, IMT‐2000, WiMAX, WiFi, and Bluetooth.