Broadband graphene–metal hybrid polarization-insensitive FSS with a wide tuning range at terahertz frequency Diptiranjan Samantaray, Sambit Kumar Ghosh, Nikhil Kumar, Ajeet Singh Verma, Raghvenda Kumar Singh, Somak Bhattacharyya Applied Optics, 2026 In this paper, a broadband graphene–metal hybrid frequency-selective surface (FSS) is designed and numerically investigated for tunable band-pass-filtering applications in the terahertz range. The unit cell of the proposed FSS comprises a gold nanostructure and a distinctive graphene pattern. These layers are separated by a thin silicon dioxide (SiO 2 ) layer and are uniformly applied on both sides of a thick foam block. The results demonstrate that the proposed FSS exhibits broadband transmission in the range of 7.71–9.89 THz. This corresponds to a fractional bandwidth of 24.77%. The originality of the proposed work, to our knowledge, lies in the incorporation of the dual-patterned graphene layers in the design, enabling the proposed FSS to provide an extended tunable filtering response. The design facilitates the preservation of continuity in the graphene pattern, promoting an efficient way of electrical biasing of the device. Simulations reveal that it can achieve a tunable transmission band from 6.67 to 10.20 THz (∼41.85%), with an adequate out-of-band attenuation when the graphene’s chemical potential is adjusted between 0 and 1.5 eV. The design is analyzed in a detailed manner with the aid of various simulated results, which have been subsequently validated by an in-house equivalent circuit model approach. The proposed FSS is polarization independent and exhibits angular stability under oblique incidence up to 40° for both transverse electric and transverse magnetic wave polarizations. Owing to these unique features, it has huge potential to be employed in EM shielding, 6G communication systems, and cognitive radio-based futuristic devices.
Microwave Devices and Circuits for Advanced Wireless Communication Design and Analysis Diptiranjan Samantaray, Somak Bhattacharyya Microwave Devices and Circuits for Advanced Wireless Communication Design and Analysis, 2025 The chapter commences with a comprehensive introduction to the fundamental ideas behind metasurfaces, as well as their use in the realm of antenna design. Moreover, this chapter delves into the physics underlying metasurfaces, elucidating their ability to alter electromagnetic waves by modifying the impedance of the medium. This chapter examines different categories of metasurfaces, including frequency-selective surfaces (FSS) and electromagnetic bandgap (EBG) structures, and their distinct roles in antenna design. The chapter covers the underlying working principles of metasurface antennas, emphasizing their unique ability to control the phase, amplitude, and polarization of electromagnetic waves. It explores the significance of unit cell design, phase gradient control, and impedance matching in the design process. A critical aspect of metasurface antennas is their multi-frequency operation, and this chapter discusses techniques for achieving versatile and broadband performance. The primary focus of this chapter is the design and analysis of antennas based on metasurfaces for GHz frequency applications. This chapter explores the most important aspects of antenna design, including radiation pattern control, impedance matching with bandwidth improvement, and gain enhancement. This chapter also demonstrates, through exhaustive case studies and numerical simulations, how metasurface antennas outperform conventional designs in terms of size reduction, beamforming capabilities, and enhanced gain. The potential impact of metasurface antennas on modern technologies like 5G communication and the Internet of Things (IoT) are also covered.
Dual Band Ingestible Antenna System for Wireless Capsule Endoscopy: Design Challenges Vikrant Kaim, Sumon Modak, Diptiranjan Samantaray, Binod Kumar Kanaujia 4th Wireless Antenna and Microwave Symposium Wams 2025, 2025 This paper aims to provide a comprehensive discussion on the challenges and key technologies associated with the design of capsule antenna systems. Furthermore, it proposes a compact CPW-fed dual-band capsule antenna system that integrates an interdigital structure and a parasitic radiator, enabling operation within the Industrial, Scientific, and Medical (ISM) bands for wireless capsule endoscopy. The functionality of the antenna is evaluated using a rat model. The simulated results demonstrate dual resonant frequencies at 0.82 GHz and 2.42 GHz, with corresponding gains of −18.7 dBi and −17.3 dBi, respectively.
Design of metasurface-inspired high-gain and low-profile LHCP antenna Manoj Kumar Shrivastava, Ripudaman Singh, Diptiranjan Samantaray, Anil Kumar Gautam, Amit Kumar Singh International Journal of Microwave and Wireless Technologies, 2025 This paper presents a metamaterial-inspired, left-handed circularly polarized (LHCP), high-gain, and miniaturized antenna with a radiation efficiency of 92.8%. A properly arranged metamaterial containing a 4 × 4 array of unit cells is placed on the ground plane of the microstrip antenna to increase the antenna’s gain up to 12.8 dBi at 10.3 GHz. Both the unit cell and the antenna are designed on an FR4 substrate with a loss tangent of 0.02 and a relative permittivity of 4.4. The overall dimensions of the designed antenna are 0.88λ0 × 0.88λ0 × 0.052λ0, where λ0 is the free-space wavelength at 9.8 GHz. The simulated bandwidth of the prototype antenna is 2.8 GHz (9.9–12.7 GHz), while the measured bandwidth is 3.2 GHz (9.8–13 GHz). The maximum simulated and measured gains are 14.4 and 12.8 dBi, respectively, at frequencies of 10.4 and 10.3 GHz. Achieving such high gain in a small LHCP antenna is the novelty of our antenna design. The bandwidth of the proposed antenna lies within the upper X-band and lower Ku-band. Therefore, this antenna is suitable for applications such as weather monitoring and air traffic control systems.
A Metamaterial Loaded High Gain Low Profile RHCP Microstrip Antenna for X-Band Applications M K Shrivastava, Ripudaman Singh, Diptiranjan Samantaray, Azharuddin Khan, Anil Kumar Gautam, A K Singh IEEE Access, 2025 This paper presents the design of a right-hand circularly polarized (RHCP) microstrip antenna loaded with metamaterial to achieve high-gain performance. The metamaterial (MTM), a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5 \times 5~$ </tex-math></inline-formula> array of unit cells with a negative refractive index, is designed on one-sided FR4 dielectric material with dimensions <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.79\lambda _{0} \times 0.79\lambda _{0} \times 0.023\lambda _{0}$ </tex-math></inline-formula>, where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> is the free-space wavelength at 8.76 GHz. Both the antenna and the unit cells are designed on an FR4 substrate with a loss tangent of 0.02 and relative permittivity of 4.4. The antenna and MTM maintain the same area, with an air gap of 1 mm between them. The overall structure achieves a gain of 8.1 dBic at 9.5 GHz with stacking, compared to 4.4 dBic without the MTM stacking. The measured bandwidth of the proposed antenna is 1.98 GHz (8.76-10.74 GHz), which falls within the lower X-band, making it suitable for both military and maritime radar applications.
A Metasurface Integrated Wide Bandwidth High Gain Patch Antenna for X-band Applications Kamisetti Sasank, Deepak Ram, Kalyani Kandiraju, Diptiranjan Samantaray, Vikrant Kaim, Somak Bhattacharyya 4th Wireless Antenna and Microwave Symposium Wams 2025, 2025 This paper presents a compact, wideband microstrip patch (MP) antenna integrated with a metasurface (MS) structure, specifically engineered for Xband applications. The antenna design incorporates a microstrip radiating patch with truncated corners, positioned on an FR-4 dielectric substrate, which functions as the primary radiating element. A metasurface layer, configured as a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4 \times 4$</tex> unit cell array, is implemented on a separate FR-4 substrate of identical dimensions and placed above the patch, acting as a superstrate to enhance electromagnetic performance. The proposed antenna achieves a −10 dB impedance bandwidth ranging from 8.29 GHz to 11.41 GHz, offering a total bandwidth of 3.12 GHz. It attains a peak realized gain of 5.88 dBi within the operating band. Due to its low profile, wide bandwidth, and high gain, this antenna is well-suited for deployment in satellite communication, telemetry operations, and unmanned aerial vehicle (UAV) data transmission systems.
Spin-Wave Mediated Microwave Antennas: A New Paradigm in Smart Antenna Engineering Rakesh Kumar Nayak, Abhishek Maurya, Diptiranjan Samantaray, Somak Bhattacharyya, Rajeev Singh, Biswanath Bhoi 2025 IEEE Microwaves Antennas and Propagation Conference Mapcon 2025, 2025 A novel strategy is introduced for reconfigurable antenna design by harnessing the dynamic interaction between microwaves and spin waves in a Yttrium Iron Garnet (YIG)loaded patch antenna. Through numerical simulations, it is demonstrated that integrating YIG enables magnetic tunability, allowing key antenna parameters-such as return loss, bandwidth, gain, efficiency, and side lobe level-to be precisely controlled without any geometric modification. An externally applied static magnetic field triggers a shift from single- to dualband operation, unlocking dynamic control over the antenna's electromagnetic response. This hybrid platform paves the way for compact, energy-efficient, and frequency-agile antennas, making it a strong contender for next-generation wireless communication, radar, and sensing applications. Our results establish a promising paradigm for smart antenna systems driven by spin wave-mediated electromagnetic reconfiguration
A Wearable Dual-Band Circularly Polarized Patch Antenna for Wearable Applications Kamisetti Sasank, Deepak Ram, Kalyani Kandiraju, Diptiranjan Samantaray, Vikrant Kaim, Somak Bhattacharyya 4th Wireless Antenna and Microwave Symposium Wams 2025, 2025 A dual-band circularly polarized (CP) wearable microstrip antenna is presented for flexible wireless applications. The proposed antenna features a rectangular patch with diagonally truncated corners, embedded with hexagonal, U-shaped, and circular slots to enhance CP performance and impedance matching. The antenna is realized on a wool-based textile substrate, offering mechanical flexibility suitable for on-body integration. It operates over two bands, with impedance bandwidths of 16.31%(4.84-5.7 GHz) and 20.9%(6.81-8.4 GHz). The axial ratio (AR) bandwidths of 1.51%(5.26-5.34 GHz) and 2.7% (6.91-7.1 GHz) right-handed circular polarization are maintained across both operational bands, with realized gains of 3.3 dBi and 11 dBi at 5.3 GHz and 7.02 GHz. The antenna's compact, conformal structure makes it suitable for wearable AR/VR, biomedical sensing, and IoT-enabled applications.
