Wideband Biconical Antenna With Embedded Band-Notch Resonator

A volumetric resonant structure is embedded inside a wideband 7–34.7 GHz omnidirectional biconical (bicone) antenna to achieve controllable, narrowband rejection within the wide instantaneous bandwidth for use in electronic support measures (ESMs). Design curves are shown for the impacts of various parameters of the resonant slot with respect to notch frequency, bandwidth, and impact on radiation characteristics. Physical realizations are demonstrated with a notch response of 3 dB or lower return loss formed between 15.3 and 16.9 GHz. The provided design curves and corresponding parametric studies exemplify the control of the band-reject region. Further examination on the steering of radiation pattern null in elevation is shown by varying the resonant slot structure between the top and bottom halves of the bicone. The biconical antenna is designed for fabrication in stereolithography (SLA) followed by electroplating. For this manufacturing approach, the band-reject bicone is compared to the corresponding base version. The prototype structures successfully validate the proposed approach.