An Omnidirectional Monopole Antenna With Horizontal Radiation Enhancement for Aircraft Wireless Avionics Intra-Communications Application

A zenithal null-filled and horizontal radiation-enhanced technique is proposed and adopted in the design of an omnidirectional monopole antenna in this work for aircraft wireless avionics intra-communications (WAIC) application. The improved monopole antenna incorporates an inverted truncated cone-shaped gradient structure, which significantly enhances impedance matching performance while simultaneously reducing the antenna profile. The circular ring with directional radiation characteristics covers the radiation blind area at a traditional monopole antenna zenith. Furthermore, the slotted cavity enhances the designed antenna's omnidirectional radiation in the horizontal direction. Based on 3-D printing and copper paste technology, the antenna prototype operates in the 3.4 GHz to 6.0 GHz frequency band with S₁₁ better than -10 dB. At 4.3 GHz, the designed antenna's minimum horizontal-plane gain and the zenith gain are -0.77 dBi and 0.45 dBi, respectively. Excellent zenith gain and omnidirectional radiation capabilities give this new null-filled omnidirectional antenna considerable potential for WAIC applications in aircraft communication systems. © 2025 IEEE.