Microwave non‐destructive testing of active frequency selective surface embedded tunable radar absorber

Abstract

The development and performance evaluation of a thin, broadband, and tunable radar wave absorber with reduced complexity is a strenuous task. This Letter reports the design, fabrication, and non‐destructive measurement of an active frequency selective surface (FSS) embedded tunable radar absorber. The proposed absorber design consists of periodically patterned, PIN diode mounted‐active transmissive/reflective FSS with a straightforward bias network. The tunable absorption characteristics are obtained over a wide frequency range by controlling the bias voltage of PIN diodes. The features of the proposed tunable absorber are demonstrated through non‐destructive free space, microwave measurement of a fabricated prototype. The measurement results show the achievement of a remarkable bandwidth of 3.0 GHz, which enables dynamic control of the absorption characteristics ranging from 8.2 to 12.4 GHz. Such an approach paves the way toward the realisation of smart materials and structures for electromagnetic wave manipulation.

Design of a wideband and tunable radar absorber

“…in this paper, whose relative permittivity r e = 4.3 and loss tangent tan e = 0.025 [19,36]. FR-4 is implemented in the design to provide protection for the graphene capacitor and act as a separator between the graphene capacitor, plasma, and RAM.…”

“…By adjusting the bias voltage on varactor diodes, Saptarshi Ghosh [18] created dual-band tunable absorber based on split square loops connected with cross-dipoles through varactor diodes. The amplitude and frequency of absorption can be controlled using the bias applied to PIN diodes, the radar absorber proposed by A Sharma [19] achieved dynamic control of the absorption characteristics from 8.2 GHz to 12.4 GHz. Cheng Huang [20] reported a tunable radar absorber by combining the graphene capacitor and AFFS loading the varactor.…”

Guest Editorial: Non‐Destructive Testing

“…The paper by Varshney et al [1 ] demonstrates applications of RF technology for non‐destructive testing of the quality of coconut by dielectric sensing, whereas Jue Lyu et al present a reconstruction algorithm for higher resolution image from under‐sampled measurements by a compressive 2D near‐field MMW super‐resolution (SR) imaging model [2 ]. The paper by Sharma et al discusses the design, fabrication, and non‐destructive measurement of an active frequency selective surface (FSS) embedded tuneable radar absorber [3 ]. In [4 ], Matsukawa presents the utilisation of time‐domain responses of microwave guided‐modes propagating along fibreglass‐reinforced plastic mortar pipelines for non‐destructive inspection of underground pipelines, whereas Pandit et al demonstrate a non‐destructive microwave resonant sensor for detecting the aqueous bio‐chemicals in [5 ].…”

Ultra-thin wideband frequency tunable metamaterial absorber and its application for antenna radar cross section reduction

“…The advent of reconfigurable technology introduces a novel approach for broadening the operational bandwidth of MMAs [24]. By incorporating adjustable components or alternative materials within the structure, the operational frequency band of the absorber can be dynamically modified as required [25][26][27][28][29]. Consequently, broadband operation can be attained without augmenting the profile height, ensuring an exceptionally high absorption rate at each frequency point.…”