For the development of terahertz (THz) wireless communication systems, the antenna needs to be in micrometer size range and give high far-field gain. Graphene is highly conductive, thermally and electrically; this article puts forward a transparent graphene-based patch antenna with metal lobbing, it resonates nearly at 1 THz and has gain nearly 5 dB. It investigates the effect of chemical potential of graphene on the return loss and resonant frequency of the antenna, this would represent the most effective way to tune radiation characteristics by tuning graphene surface impedance. The performance of designed graphene antenna is compared with its metallic counterpart as a reference antenna, the former outperforms the latter in terms of spectral characteristics. Besides that, metallic thin films are prone to fail because of microcracks which give a compelling reason to switch to graphene antenna for future communication in the THz domain. K E Y W O R D S glass substrate, graphene, miniaturized, terahertz patch antenna, tunable | I NTRO DUC TI ONGraphene is a tightlypacked 2-dimensional cluster of carbon atoms with high mechanical strength, a unique electronic spectrum, exceptionally high electrical and thermal conductivities, and impermeability to gases. These properties can lead to a lot of explorations for applying graphene into diverse research areas. 1 The discovery of graphene has fuelled experimental research in the field of high energy physics and quantum relativistic phenomena. 2 The use of graphene in antenna application started by simply taking it as a parasitic layer for improving the radiation pattern of a metal antenna. 3 Then the TM Surface Plasmon Polariton waves (TM SPPs) were found on the monolayer graphene sheet in 2011. 4,5 As a result of the slow propagation of SPPs, miniature and low-profile graphene antennas can be achieved by adapting graphene sheet as radiation part. 6 Consequently, a number of works were published to show the theoretical results on radiation characteristics of the graphene 3,7-9 in recent years.As a result of the complicated mechanism and modeling of the graphene-based antenna, the simulation process is very intricate to demonstrate the theoretical principle of antenna resonant performance. The performance mainly depends on the antenna dimensions, graphene properties, and substrate parameters. Hence, it is a miscellaneous process to optimize the antenna to the expected performance since it involves a range of parameters. To facilitate the initial rough design of the antenna, as well as the understanding about antenna resonance property, the resonance circuit model for graphenebased antenna should be studied to comprehensively understand such antennas.Albeit, graphene has been the epicenter of research since 2004. Only a few studies focused on graphene's radiator application 10 can be found in the literature. Prior studies have proposed a one-side-excited graphene patch antenna, suspended in the air 5 and it has been depicted that graphene antenna offers good tunability in t...

This paper presents a simple broadband planar monopole microstrip patch antenna with curved slot and partial ground plane. The proposed antenna is designed and fabricated on commercially available FR4 material with εr = 4.3 and 0.025 loss tangent. Bandwidth enhancement has been achieved by introducing a curved slot in the patch and optimizing the gap between the patch and the partial ground plane and the gap between the curved slot and the edge of the patch. Simulated peak gain of the proposed antenna is 4.8 dB. The impedance bandwidth (defined by 10 dB return loss) of the proposed antenna is 109% (2–6.8 GHz), which shows bandwidth enhancement of 26% as compared with simple monopole antenna. The antenna is useful for 2.4/5.2/5.8-GHz WLAN bands, 2.5/3.5/5.5-GHz WiMAX bands, and other wireless communication services. Measured results show good agreement with the simulated results. The proposed antenna details are described and measured/simulated results are elaborated.

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In this communication, a practically realisable artificial planar magneto‐dielectric (MD) meta‐substrate is proposed and investigated for microstrip patch antenna miniaturisation. The meta‐substrate employs cross‐coupled twisted metallic split‐ring resonator ring pairs to achieve effective permeability (μeff) and permittivity (ɛeff) greater than that of the host dielectric which leads to antenna miniaturisation. Electromagnetic simulation and analysis of effective material parameters are performed to characterise it, which shows nearly equal enhanced effective permeability and permittivity (μeff ≃ ɛeff) at 2.35 GHz with low loss‐factor level not achievable from natural materials. An inset fed microstrip patch antenna is designed on the proposed MD meta‐substrate to test and validate its performance. The performances of the miniaturised patch antenna loaded with proposed dispersive MD meta‐substrate, non‐dispersive homogenous MD substrate, and high‐permittivity substrates (lossy and loss‐free) are compared with the conventional patch antenna on host dielectric. It is found that dispersive nature of the meta‐substrate plays a critical role in the antenna performance. The antenna on proposed meta‐substrate occupying an overall volume of 0.250λ0 × 0.344λ0 × 0.009λ0 at 2.35 GHz is 74.83% miniaturised as compared with the conventional antenna on host dielectric. To ensure the practicability, the designed antenna is fabricated and measured.

This paper presents a compact broadband printed monopole antenna with U-shaped slit in the partial ground plane and rectangular parasitic patches adjacent to the microstrip line for multiple applications. The optimal dimensions of the proposed antenna are 35 × 25 × 1.5 mm3 and is fabricated on commercially available low-cost FR4 substrate with εr = 4.3 and 0.025 loss tangent. Due to introduction of rectangular parasitic patches and U-shaped slit large bandwidth has been achieved. The impedance bandwidth (return loss, magnitude of S11 < 10 dB) of the proposed antenna is 139% (2.9–16.3 GHz). The proposed antenna covers ultra wide band applications, 5.2/5.8 GHz WLAN bands, 3.5/5.5 GHz WiMAX bands, X band (8–12 GHz), satellite communication, and other wireless communication services. The study shows that there is good agreement in simulated and measured results. Nearly stable radiation patterns have been obtained throughout the operating band. Antenna results and details are discussed and elaborated.