A Capacitive Coupled, Low-Profile, Wide Beamwidth Antenna on Unmanned Probe Car

A low-profile, wide beamwidth antenna at X band is proposed. The antenna stems from capacitive loaded monopole antenna, achieving low profile by using shorting end and capacitive coupled structure. A profile of 0.9mm ( 0.027λ) at 9.1GHz is obtained. The antenna realizes vertically polarized quasi-omnidirectional radiation pattern in the azimuthal plane. The whole structure is simple and easy to fabricate, which has a promising application prospect in the field of conformal antenna on an unmanned probe car.