Improved performance of an axially-modulated conformal leaky-wave holographic antenna through using variable modulation index

Abstract

In this paper, a novel method to decrease the sidelobe level (SLL) of conformal leaky-wave antennas (CLWAs) which are synthesized based on the holographic techniques is proposed. For this purpose, the holographic relation is modified by using the modulation index as a function of the spatial component corresponding to the propagation direction of the reference wave. In order to create a fascinating impedance matching between the launcher and the radiative metasurface, an initial phase is considered in the holographic formula. The designed one-dimensional (1D) sinusoidally modulated conformal antenna indicated a broadside fan beam at 18 GHz. At this frequency, about 3 dB SLL reduction was observed in the E-plane compared the traditinal holographic antenna. The measurement results indicated that the realized gain of the novel antenna at the design frequency was about 14.6dBi, and the SLL and the radiation efficiency of the antenna were −10.6 dB and 95%, respectively.

KEYWORDS:

• Conformal leaky-wave antenna
• holographic antennas
• surface impedance
• metasurface
• SLL reduction

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors would like to acknowledge the financial support of Iran National Science Foundation (INSF) for this project.

Notes on contributors

Mohammad Amin Chaychi zadeh

Mohammad Amin Chaychi zadeh was born in Tabriz, Iran, in 1987. He received the B.Sc., M.Sc. degrees in Electrical Engineering from university of Tabriz and Iran University of Science and Technology , Iran, in 2009, and 2013, respectively. He is currently working toward the Ph.D. degree in Communication Engineering in Iran University of Science and Technology (IUST), Tehran, Iran, since 2016. His major research interests are design and implement metasurfaces for various applications, novel methods for designing periodic structures, microwave, antennas, and applied EM.

Nader Komjani

Nader Komjani received his B.Sc., M.Sc. and Ph.D. degree all in Electrical Engineering from Iran University of Science and Technology, Iran, in 1988 and 1991, and 2000, respectively. He is currently the associate professor with Iran University of Science and Technology. He has taught microstrip antennas, communication systems, advanced engineering mathematics and electromagnetic courses since 1998. His area of interest includes UWB and multiband microstrip antennas, numerical methods in electromagnetic, phased array antennas and passive and active microwave systems.