This article demonstrates a simple graphene enabled THz antenna constructed on polyimide dielectric substrate having Epsilon $(\varepsilon)=3.5, M u(\mu): 1$, Electric dielectric loss $\text{tangent} =0.0027$, Poisson's ratio = 0.4, Young's modulus = $2.5 \text{kN} / \text{mm}^{2}$, and height $(h)=2 \mu \mathrm{m}$. This THz antenna has a compact dimension of $22 \times 22 \mu \mathrm{m}^{2}$. The simulated S11 parameter, VSWR, Z-parameter, radiation patterns and absolute gain are analyzed in details. Its resonant frequency of this antenna occurs at 6.4 THz, having return loss of - $35 d B$. This antenna has impedance bandwidth of 126.1 GHz, which has return loss less than $-10 d B$ while maintaining voltage standing wave ratio $(V S W R)<2$ in its operating frequency. The polar plot radiation characteristics is almost like as monopole/dipole antenna. The proposed antenna has all favourable performance parameters which is suitable for Cancer detection in biomedical and ultra-high data rate applications.

A wideband, dual-element MIMO antenna operating in 2.83-7.21GHz frequency bands is presented in this study.The proposed design consists of a stub-loaded partial ground plane and a stepped feedline with a dual circle-shaped radiator on top.The designed MIMO antenna operates from 2.83 to 7.21 GHz, covering the C band (4-8 GHz) and 5G (sub-6 GHz) applications.The peak gain observed is 4.8 dBi at 6.2 GHz, with a maximum efficiency of 92% at 3.2 GHz.The minimum port isolation and ECC over the bands 2.83-7.21are observed as 22 dB and 0.003, respectively.To achieve the best outcome, a parametric analysis of the proposed antenna is also simulated.Various diversity characteristic metrics, including diversity gain (DG), mean effective gain (MEG), total active reflection coefficient (TARC), channel capacity loss (CCL), and ergodic channel capacity (CC), are thoroughly analyzed to determine how well the MIMO antenna performs in terms of diversity.In all operating bands, the measured values provide good agreement with simulation results, indicating a strong candidacy for operation in the investigated bands.

This research suggests a compact, wideband Multiple Input Multiple Output (MIMO) antenna designed for S-band applications, emphasizing high isolation between closely positioned antenna elements.Achieving this isolation is accomplished through the implementation of a Defected Ground Structure (DGS) technique.The DGS is realized by etching two elliptical patterns on an economical FR-4 substrate with inherent loss properties.Three rectangular slots and two L-shaped stubs are introduced to improve isolation and minimize the size of antenna increment by lowering surface wave propagation.To validate the proposed layout, a physical prototype was constructed for a direct comparison of its performance with the simulated parameters.The results demonstrated highly favorable outcomes, including Diversity Gain (DG) exceeding 9.97 dB, Envelope Correlation Coefficient (ECC) registering below 0.05, Mean Effective Gain (MEG) lower than -3 dB, Total Active Reflection Coefficient (TARC) below 0.4, and Channel Capacity Loss (CCL) less than 0.3.Furthermore, the current distribution and radiation pattern were found to be highly suitable for applications in the S-band and the lower part of the C-band, encompassing technologies like Bluetooth, WiFi, WiMAX, 4G, and 5G.

A planar compact dual-band filtering antenna based on the filter synthesis technique is proposed in this chapter. The filtering antenna consists of a stub-loaded square loop resonator, a coupled line inverter, and an inverted L antenna. The filtering antenna exhibits a dual-band filtering response with an impedance bandwidth of 4.14% (2.36–2.46 GHz) and 3.85% (3.56–3.70 GHz). To validate the concept, a filtering antenna is fabricated and measured. The simulated and measured result agrees well and indicates that the proposed filtering antenna attributes a compact size of 19 mm × 27 mm, with a gain of 0.77 dBi and –0.08 dBi in the operating range 2.36–2.46 GHz and 3.56–3.70 GHz, respectively. The results indicate that the proposed antenna is a suitable candidate for C-band applications.

Abstract This paper presents a circular monopole antenna with uniquely packed quad T-shaped strips etched on FR4 epoxy substrate having material permittivity 4.4, loss tangent 0.02, and thickness 1.6 mm. The 3.5 GHz band is achieved through this arrangement, which has return loss less than −10 dB while maintaining VSWR <2. It provides a peak gain of 2.65 dBi at 3.5 GHz and average gain of 2.52 dBi in the entire operating frequency band. The radiation pattern is almost omnidirectional in E plane and bidirectional in H plane. The proposed antenna has a compact size of 41.25 mm × 30.55 mm. The simulated results of S11 parameters, gain, VSWR, radiation pattern, and efficiency are studied and verified with the measured results of fabricated antenna as well as its equivalent lumped circuit model. Investigation shows that the proposed antenna can be employed for WLAN/WiMAX applications efficiently.

Abstract Modern communication systems require an antenna with miniaturized size and large bandwidth with high data rate. In this article, a circular monopole antenna is presented with hexagonal patch on both sides of microstrip feedline and an I- shaped rectangular slot etched at the center of feedline to provide impedance matching. The modified loaded ground reduces the coupling between ground plane and radiation patch. This antenna has compact dimension of 30 mm × 25 mm with electrical size of 0.25λ × 0.20λ. This antenna has been designed and simulated in HFSS commercial software and fabricated on FR4 substrate of thickness 1.6 mm with relative permittivity 4.4, loss tangent of 0.02. The experimental results are compared with simulated one, which are in close agreement. It attains a frequency band ranging from 2.4 to 56.6 GHz with reflection coefficient <−10, percentage bandwidth of 183.72%, Bandwidth Ratio (BR) 23.58:1, and Bandwidth Dimension Ratio (BDR) of 3674.40. The peak gain and radiation efficiency of this antenna is 12.77 dBi and 98.82% at 45.84 and 5.6 GHz respectively. Time domain analysis has been done, which proclaims that the proposed antenna has SWB characteristics. It may be useful for high data rate transmission, medical imaging, and other SWB applications.

A narrowband planar monopole filtenna using filter synthesis technique is demonstrated in this paper. A Square open loop resonator along with L shaped antenna is utilised to get the filtering characteristics. A coupled line used to integrate filter and antenna without extra matching circuitry. It consists of one arm of the last resonator filter and extended feed arm of the antenna, for proper integration between filter and antenna. The simulated result shows that, the proposed filtenna provides a narrow impedance bandwidth of 7.14% (2.43 - 2.61 GHz) with a good selectivity at band edges, wide rejection band, with an omnidirectional radiation pattern well suited for wireless application.

With a recent development and phenomenal activity in the area of microwave, there is need to maintain quality of service and high data rate. Therefore, requirement to design an antenna which provide these facilities. This paper presents a double regular hexagonal radiating patch, defected ground, and small circular slot etched out from the middle part of radiating patch. It demonstrated the Ultra-Wide band (UWB) operation, which works efficiently in entire band from 2.52 to 12.91 GHz. The overall dimension of proposed antenna is 31 × 51.5 mm2 Simulated in HFSS and has almost stable radiation pattern of E- and H-plane, positive gain of 6 dBi, and 134% of bandwidth in the entire band. This microstrip antenna is simulated and fabricated to verify its result, the equivalent circuit model is also constructed to verify simulate a measured result, which works efficiently in S, C, and X band applications.

Custom designed microstrip antennas are currently the preferred choice of creative antenna designers because of its record low better linear gain and efficiency, high bandwidth, favorable radiation pattern and easy to manufacture as they can be printed into the circuit board directly. This paper proposes a uniquely packed microstrip antenna of dimension 39.5 × 31 mm2 for Bluetooth-enabled devices which have myriad of applications ranging from healthcare, Internet of things and entertainment. The antenna structure is simple and consists of concentric elliptical strip-shaped patch designed on an inexpensive FR4 substrate. The dielectric constant and thickness of substrate is 4.4 and 1.6 mm, respectively, to match the microstrip material dimension so that devices can be used over a broad temperature range. The presented antenna operates at 2.4 GHz resonances frequency, transmits and receives linearly polarized radiation which are omnidirectional in nature, provides stable gain covering 2.38–2.42 GHz. VSWR of 2 is obtained signifying a good impedance matching with 50Ω microstrip feedline and SMA connector. Design and analysis is done by HFSS 19.0 simulation software. Measurements of parameters of fabricated antenna are in conformity with simulation values. Equivalent circuit analysis result is presented to along with experimental and simulated results to authorize the need for Bluetooth-enabled devices.

This paper presents a low-profile quadrilateral-shaped fractal slot planar antenna using a novel fractal geometry where circular, triangular and regular hexagonal motifs are iterated to form antenna elements. It consists of a partial ground plane and a triangular fractal-shaped patch fed by a microstrip line having an I-shape rectangular slot to increase the bandwidth. A compact 32 × 22 mm2 fractal antenna proposed here is investigated to evaluate its performance in ultra-wideband (UWB) applications. The bandwidth of 15.5 GHz ranging from 3.57 GHz to 19.07 GHz with voltage standing wave ratio (VSWR) less than 2 in the entire operating band is achieved. Simulated values of realisable gain (6.8 dBi), impedance bandwidth (15.5 GHz), radiation efficiency (90%), radiation patterns and group delay evaluation indicate that the discussed antenna is favourable for UWB applications such as world interoperability microwave access, wireless local area network, 5 G, X-band, C-band, S-band and Ku-band. The proposed antenna is fabricated, and measured results are compared with simulated results as well as with those reported in the literature.

A compact hexagonal-square shaped fractal monopole antenna is etched out from circular patch for ultra-wide band application. This proposed antenna has an overall physical dimension of 54 × 35 mm2.The parameters of antenna such as Return loss, percentage Bandwidth, VSWR, E-plane and H-plane pattern, Gain, are analyzed. The partial ground plane and microstrip transmission line is employed to achieve ultra-wide band (UWB) operating bandwidth from 2.1 to 13.5 GHz (155%) with reflection coefficient close to −30 dB. This makes it suitable for the commercial, aerospace, and military telecommunication besides the traditional radar imaging application. The proposed antenna is fabricated. The simulated and measured outcomes are in very close agreement.

In this paper, an ultrathin Swastik shape unit cell structure of a metamaterial absorber (MA) is capable of increasing absorption in the X-band spectrum for a variety of applications. The structure of the MA is arranged periodically and has a swastika shape with lumped resistor resonator. In addition to having an intuitive design, the unit cell structure is able to absorb more than 80% of the desired band. The simulated result shows two absorption peaks at 5.05 and 12.60 GHz with more than 95% absorptivity. A proposed absorber provides absorption bandwidths between 4.19 and 13.33 GHz (9.14 GHz) in Full-Width Half Maxima (FWHM). An ultrathin absorber has a thickness of 0.035 mm, which is nearly λ/10 corresponding to the absorption central frequency of 8.67 GHz. The unit cell’s size of MA is 9 × 9 mm2, with a thickness of 3.2 mm (0.0346 λ).

Fractal geometry antennas are much sought after in present scenario of wireless communication due to ever increasing demand for high gain, wide bandwidth, low cost, compact size and easily deployable antennas. An ultrawide band monopole antenna using compact hexagonal-square shaped fractal geometry is proposed here, which nearly fulfils the above demands. The fractal geometry is introduced by iteration of square slots in the hexagonal radiating patch etched on a circular chunk. The proposed antenna achieves percentage bandwidth of 146% approximately ranging from 2.1 to 13.5 GHz with return loss of -25 dB and voltage standing wave ratio (VSWR) less than 2. It achieves maximum peak gain of 7.2 dBi at 11.7 GHz and an average gain of 3.9 dBi in the entire operating range of frequency, efficiency of 87.57% and good radiation pattern. Aprototype of simulated antenna is developed and the tested results are validated using equivalent circuit model as well. The results are in conformity with each other. Therefore, the proposed design can be used for UWB applications such as Bluetooth (2.4 GHz), LTE (2.3 GHz), WLAN (2.4 2.48 GHz), 5G, WiMAX (2.5 - 2.69/3.4 - 3.69/5.25 - 5.85 GHz), military communication in C-band, satellite communication in X-band and S-band.

This article presents a simple compact microstrip feedline printed antenna that can minimize the consequences of frequency interference, thereby, providing good stable omnidirectional radiation pattern and transmission response within whole range of desired frequencies. The proposed antenna has two regular shaped hexagonal radiators, a mictrostrip-fed line and a partially extended ground plane perturbed by a circular slot inserted at the centre. The partial ground plane with a circular slot at the center plays an important role in the broad band characteristics of the proposed antenna, because they can adjust the electromagnetic coupling effect between patch and ground plane and improve the impedance bandwidth. The simulation and measured results are in close agreement and show that a wide bandwidth of 10.39 GHz (2.52-12.91 GHz) at -10 dBi return loss with voltage standing wave ratio less than two is achieved by this antenna. The antenna is compact (0.37 lambda x 0.24 lambda), has good radiation pattern, appreciable gain of 5.97 dBi and 134% fraction bandwidth which is favorable for ultra-wide band applications such as S, C, X, WLAN, and WiMAX. The equivalent lumped circuit model of the proposed antenna is also presented for validation purpose. The proposed antenna in particular focusses on 3.4 to 3.6 GHz frequency band with centre frequency 3.5 GHz (sub 6 GHz 5G band) and WLAN/Wi-Fi (3.6/4.9/5.9 GHz) applications.

In this paper this fractal structure is executed on hexagonal C and a few cycle is applied on beginning shape. This reception apparatus has lowprofile, lightweight and is anything but difficult to be manufactured and has effectively exhibited multiband and broadband qualities. The mimicked outcomes showthat proposed reception apparatus has excellent execution in impedance transmission capacity and radiation design.

This paper proposed a comparison of stepped impedance fractal low pass filters at 1 GHz with open stub and short-circuited stub. Sierpinski carpet fractals used to reduce filter size and develop low profile filters. Fractal elements or arrays are designed with the concept of self-similarity to achieve sharper cut off point. 1 GHz low pass filter is used for long range communication and smart phone communication for IOT application. KeywordsFractal, Chebyshev Response, Stepped Impedance Low Pass Filter, Open Circuited Stub, Short Circuited Stub