Design of an omnidirectional conical beam leaky wave antenna using the holographic technique

The microwave holographic principle offers a promising framework for designing leaky-wave antennas (LWAs) with conical radiation patterns. In this paper, a holographic method is presented to synthesize an omnidirectional LWA with angular scanning capability in elevation. This paper proposes the aperture field estimation theory for synthesizing holographic leaky-wave antennas. Its advantage is the accurate prediction of far-field pattern characteristics, such as amplitude, phase, and polarization. To excite the hologram, a monopole launcher is placed in the center of the structure. To demonstrate the validity of the design method, an LWA is fabricated and measured in an anechoic chamber. The proposed holographic principle is validated through experimental results in terms of impedance bandwidth, maximum realized gain, radiation efficiency, and radiation patterns. The measurement results exhibit an impedance bandwidth of 20% (9-11 GHz) with an average realized gain of 12.5 dBi in the operating frequency band. In addition, at the design frequency of 10 GHz, the maximum realized gain, beam scanning, sidelobe level (SLL), and radiation efficiency are 13.1 dBi, [Formula: see text], -10 dB, and 91%, respectively. The measured results agree well with full-wave simulations performed in CST software. The proposed holographic antenna can be a good candidate for wireless communication applications.