Ansoft HFSS Research Articles

A New Compact, Stable, and Dual-Band Active Frequency Selective Surface with Closely Spaced Resonances for Wireless Applications at 2.4 and 2.9 GHz

This paper presents a dual-band active frequency selective surface (AFSS) with closely spaced bands and angular stability for wireless applications at 2.4 and 2.9 GHz. The proposed AFSS element geometry is composed of a slotted cross dipole combined with four ring patches, where the diameter of the ring patches at the top of the geometry is 1.618 times greater than the diameter of the ones at the bottom. The choice of this multiplying factor, used to define the geometry of the proposed patch element, is based on the Fibonacci sequence of numbers. In addition, to perform frequency reconfiguration, two p-i-n diode switches are used, which are placed at the input of the ring patches placed at the top of the AFSS element geometry. The AFSS simulation is performed using Ansoft HFSS software and using generalization of the WCIP, i.e., GWCIP, method. The simulated results are compared with the experimental ones for validation purpose. A very good agreement is observed between the simulated and measured results.

Design and Optimization of V-Shaped Microstrip Patch Antenna with enhanced Bandwidth in Broadband Applications

This paper a compact V- shaped slotted microstrip antenna is designed and utilized in the various communication systems. The most common important parameters are improved .The results of the measured and simulated results for V-slotted microstrip patch antenna has been analyzed . The V slotted patch antenna has been designed to tested in laboratory .The measured and simulated results are exhibits good agreement. The proposed antenna achieved 174MHz of bandwidth at resonance frequency of 2.4 GHz with VSWR ≤ 2. The antenna constructed at centre frequency of 2.44 GHz. The antenna has been designed and simulated using Ansoft HFSS software tools. Then, the antenna parameters are varied in a specific intervals and analysis the designed Patch antenna. Then antenna bandwidth can be enhanced by increasing the substrate thickness. The measured resonant frequency is found 2.592 GHz. The measured value of the bandwidth of the antenna is 75 MHz. Then, the variation of parameters and its performance are investigated.

Performance Analysis of Pentagon Shaped Microstrip Patch Antenna with Different Substrate Materials

Microstrip patch antennas are the handiest antennas for the present trend of applications in communications. The well-known beneficial mechanical characteristics (low profile, light weight, planar but conformal to non-planar structures, easy to fabricate), flexibility in terms of electromagnetic parameters like radiation pattern, gain, impedance, polarization and low cost are the key features for the success of such antennas. High efficiency antennas are essential to cater the requirements of various military oriented space vehicles like spacecraft, aircraft, satellite and missile applications where dimensions of installation are important as size, weight, performance, ease of installation and easy integration to the circuit. Microstrip antenna array are most apt for such applications, but the limitation of such antennas are gain and the bandwidth. The order of gain is low for patch antenna which is generally in the choice of 1-2dB.To increase gain and bandwidth factors the utilization of material with low dielectric constant having greater thickness is employed. However, this generates surface waves. So, proper thickness of substrate is selected. In this paper, microstrip patch having pentagon shape uses probe feed technique for various substrate materials such as Roger’s RT/Duroid 5880 (tm), Roger’s RO4003 (tm) and FR4 epoxy. The results of the three substrate designs are acquired for the resonant frequencies 6.5 GHz, 6.6 GHz, and 6.7 GHz respectively. The whole analysis is carried out using Ansoft HFSS software version 17.0. The characteristics like bandwidth, amplification factor (gain), return loss and radiation patterns of the different antenna are assessed, related and the same are presented at the end.

Simulation and Design of a Bandpass Filter Based on Substrate Integrated E-Plane Waveguide

This paper presents a bandpass filter based on a substrate integrated E-plane waveguide (SIEW) structure for wireless applications, at X-band. The SIEW geometry allows the development of new horizontally polarized filter topologies, unlike filter structures based on substrate integrated waveguide (SIW), which present vertical polarization (perpendicular to the ground plane). The simulation of the proposed SIEW filter is carried out using Ansoft HFSS software. To evaluate the performance of the proposed structure, the frequency behaviors of the scattering parameters are obtained for a horizontally polarized excitation. In the simulation, analyses are performed for the lossless and lossy (dielectric and metallic) cases, in order to compare the obtained results. The SIEW filter is fabricated and measured using a vector network analyzer (VNA). Measurement results are in agreement with simulation ones, validating the proposed filter design and topology. The fabricated prototype resonates at 10.54 GHz, with a bandwidth of 1.20 GHz, defined for a -3 dB transmission coefficient reference level. The SIEW filter structure is easy to design and manufacture and can be used in wireless communications systems that require components with ease integration into other planar structures.

A New Conductive Ink for Microstrip Antenna and Bioinspired FSS Designs on Glass and Fiberglass Substrates

Abstract This paper describes an investigation of the possibility of using a new conductive ink, insted of copper clad laminates, in the manufacturing of microstrip patch antennas on glass and fiberglass substrates and of bioinspired frequency selective surfaces (FSSs) on fiberglass substrates for wireless communication systems. The new conductive ink is developed using synthesized nitrocellulose which, in ethyl acetate solution, works as a bonding agent and carrier for the formation of a conductive film. The load used in the fabrication process is silver metallic powder. Simulation and analysis are performed using Ansoft Designer and HFSS softwares. Microstrip antenna and FSS prototypes are fabricated and measured for comparison purpose. An agreement is observed between simulation and measurements results.

Patch microwave absorber for RF energy harvesting as renewable energy

Renewable energy is a form of energy produced from natural resources. Besides from nature, renewable energy can also be obtained from electronic devices that emit electromagnetic waves. Electromagnetic waves can develop and be used as a source of power, especially low power consumption equipment such as sensors. One method that can be used to harvest the electromagnetic waves is of Energy Harvesting method using microstrip antenna. Energy Harvesting is one of the green technologies that are rapidly evolving nowadays. This study aims to design a microstrip antenna to harvest energy with 1x2 parallel array configuration and ISM (International Standard for Mobile communication) frequency operation of 2.4 GHz. The antenna’s performance is based on the value of Voltage Standing Wave Ratio (VSWR), Return Loss (S11), gain and radiation pattern. Ansoft HFSS v.13 simulates the antenna’s design. The simulation results are compared with the measurement results to analyze the antenna performance. The results showed that VSWR and Return Loss parameters in simulation and measurement have different performances, but still intolerance performing range. The simulation antenna gain obtained 2.52 dB.

A Design of Multiband Antenna using Main Radiator and Additional Sub-Patches for Different Wireless Communication Systems

A design of compact printed multiband Microstrip antenna for the different wireless communication systems is proposed. The antenna comprises of a main radiating patch and some additional sub patches which is fed by a microstrip line feeding. This configuration is designed to operate with the center frequencies of 1.52GHz, 1.86GHz, 2.7GHz, 3.32GHz and 4.05 GHz with achievable bandwidths of 6%, 4.3%, 3.7%, 7% and 8.4%, respectively. These five bands supports for the applications of GSM1800, GPS, WIMAX I (2.7 - 2.8GHz), WIMAX II (3.3-3.4GHz), and Fixed Satellite Services. In this work, Reflection co-efficient for each band (S11= -17.16dB for 1.5GHz, S11 = -14.75dB for 1.87GHz, S11 = -13.89dB for 2.7GHz, S11= -21dB for 3.32GHz, S11 = -33.98dB for 4.05GHz), VSWR, and Radiation patterns are simulated using Ansoft HFSS. Antenna is fabricated using ELEVEN LAB then reflection coefficients and VSWR values of the proposed antenna are measured by using the network analyzer. Simulated results are good agreement with practical results.

Design of Simple and Double Ridge Waveguide T-Coupler for Space Domain

The T-Coupler or the magic tee (or magic T or hybrid tee) is a hybrid or 3 dB coupler used in microwave systems. It is an alternative to the rat-race coupler. In contrast to the rat-race, the three-dimensional structure of the magic tee makes it less readily constructed in planar technologies such as micro strip or strip line. The magic tee was originally developed in World War II, and first published by W. A. Tyrell of Bell Labs in a 1947 IRE paper. Robert L. Kyhl and Bob Dicke independently created magic tees around the same time. This paper illustrates simple and double ridge waveguide T-coupler. The relationships between the scattering variables in this sort of network are fixed by the unitary condition. Such a network has the properties that it is a matched device with one adjacent port decoupled from any incident port. The object of this paper is to present some results of simulation on the coupling and directivity of double ridge cross-waveguide couplers in a field ridge waveguide. This results are obtain by Ansoft HFSS using the Finite Element Method (FEM) calculations and the Genetic Algorithms method, and which show good performance.

Analytical Design Procedure for Forward Wave Couplers in RGW Technology Based on Hybrid PEC/PMC Waveguide Model

In this paper, a systematic design methodology of a 0dB and a 3dB forward couplers based on the ridge gap waveguide (RGW) technology is presented. This methodology is based on exact theoretical formulations rather than any approximate or empirical equations. The procedure of the proposed design methodology is mainly to build a virtual equivalent waveguide model. This waveguide has two horizontal upper and lower perfect electric conductor (PEC) walls, while the left and the right walls are made of perfect magnetic conductors (PMC). A detailed analysis for this hybrid PEC/PMC waveguide, a common waveguide for coupling, is introduced as the starting phase for designing the RGW couplers. The equivalent RGW coupler that assures the same operation of the hybrid PEC/PMC waveguide at a specific frequency range is deduced based on detailed theoretical aspects. Moreover, a simple analyzing of transitional bends and phase shifters with accurate calculations is presented in this paper, which are the fundamental building blocks of several mmW components such as the six-port junction and the butler matrix. The possibility of tuning the coupler center frequency is introduced without the need of using any nonlinear elements. The resulting RGW couplers are implemented through well-known full wave simulator (Ansoft HFSS), with verification through prototype measurements in order to confirm the validity of the proposed methodology. A good agreement is achieved between measurement and simulation results.

Square Patch Antenna for Breast Cancer Diagnosis at 2.45 GHz

This paper presents a model of cancer diagnosis using principal electrical parameters of tumor cells such as the relative permittivity and the conductivity. The proposed model involves a square microstrip antenna and breast phantom comprising a tumor cell. The radiation properties of the designed antenna at the ISM bands, such as the Return Loss (RL), the current density, the electrical field and the Specific Absorption Rate (SAR) are exploited for diagnosing purposes. The Ansoft HFSS (13.0) simulated results show that the difference in terms of the RL, the current density, the electrical field and the SAR is higher than 2 dB, 40 A/m2, 100 V/m and 20 W/kg respectively, once the tumor exists inside the breast model. This proposed technique in turn can be exploited to distinguish malignant cells inside the women breast in earlier stages as compared to other traditional techniques such as mammography, X-ray, ultra-sound, tomography and MRI.

Evaluation of Electromagnetic Field Data of a Designed Microstrip Patch Antenna Structure According to Type of Substrate Materials and Their Thicknesses

Abstract Substrate material used in microstrip antenna structures fully impact the performance of antenna and applications of it. In this work, simulations are carried out for microstrip antenna structure used in biomedical applications. Heart vessel structure used for determining heart diseases is modelled in Ansoft HFSS program. Simulations are implemented with and without occlusion in heart vein. Antenna structure is simulated with different substrate materials and different thicknesses of them. After simulations, various electromagnetic field data are obtained and evaluated for dissimilar substrate materials and thickness of them.

Radio frequency response of flexible microstrip patch antennas under compressive and bending loads using multiphysics modeling approach

This research article studies the effect of compression and bending loads on resonant frequency of microstrip patch antennas using COMSOL Multiphysics software (will be called COMSOL hereafter). In this study, copper microstrip patch antenna of dimension 30 mm × 25 mm on polydimethylsiloxane (PDMS) substrate of dimension 50 mm × 50 mm is considered. The interface bonding is assumed to be ideal between the patch and substrate. Both Ansoft HFSS and COMSOL are used to model and analyze the original geometry of the microstrip patch antenna without applying physical load to make sure that the design and the impedance match is satisfactory. Then, COMSOL is used to find deformed shape of the microstrip patch antenna under different values of compression and bending loads. The deformed geometries are reanalyzed using COMSOL radio frequency (RF) simulation. The resonant frequencies at different load levels are obtained and the effect of loading and boundary conditions on the resonant frequency shift is discussed.

Mutual coupling reduction with a novel fractal electromagnetic bandgap structure

This work shows the effect of a novel fractal-based electromagnetic bandgap (FEBG) structure between dual planar inverted-F antenna (PIFA) elements. The FEBG structure without any shorting pins builds on a well-known fractal structure called Sierpinski carpet, where two iterations have been applied as a uniplanar EBG between dual PIFAs elements to increase the isolation. The proposed antenna can operate at ~2.65GHz for wireless long-term evolution application with compact design dimensions. The simulations are carried out with Ansoft HFSS ver. 17.0. The second iterative order FEBG band-gap characteristic is verified using more computationally efficient analysis. An investigation on coupling reduction showed more than 27 and 40dB in E -plane and H -plane, respectively, between the dual antenna elements is achieved for an antenna spacing less than half wavelength. The proposed antennas with and without second iterative order FEBG are fabricated and measured. The measurement results are in good agreement with the simulated results. Moreover, the envelope correlation of antenna elements with the proposed FEBG is quite smaller than that of antenna elements without FEBG, which gives the proposed system an excellent diverse performance and suitable for the use in low-frequency narrow-band multiple-input, multiple-output applications.

Wide‐bandwidth multifrequency circularly polarized monopole antenna for wireless communication applications

In this article, wideband circularly polarized monopole antennas with multiresonating frequencies are presented for Bluetooth, WLAN, WiMAX, and X-band applications. The designed antennas have dimensions of 50 × 35 × 1.6 mm3. Two different substrates (FR4-epoxy and PTFE) are used for fabricating the antennas. The antennas consist of corner truncated I-shaped and C-shaped strips excited by a 50 Ω microstrip feed line. The parametric analyses are performed with the help of Ansoft HFSS V.11 EM simulator. Both antennas have been fabricated and measured. The measured percentage bandwidth of the antenna made by FR4 substrate is 31.32% (centered at 1.66 GHz), and 64.85% (centered at 5.69 GHz). The percentage bandwidth of antenna made by PTFE substrate is 20.57% (centered 2.43 GHz) and 68.74% (centered at 7.39 GHz). In addition to that, there exists 3 dB AR bandwidth for LHCP of about 1050 MHz for 5.2 GHz WLAN-band. The reflection coefficient, radiation patterns, and the gains of both the antennas are studied in detail. It is found that the measured and simulated results are in good agreement.

A Novel Dual Band Hexagonal Antenna for Bluetooth and Uwb Applications With Single Band Notched

This paper presents a regular hexagonal antenna for ultra wide bandwidth (UWB). Then this antenna is modified to obtain a dual band with single band notched.The Bluetooth band is integrated in ultrawideband (UWB) when the antenna is loaded by pair of inverted 𝛤-shaped strips.To avoid interference with the uwb systems , the wireless local area network of 5.72–5.825 GHz (IEEE 802.11a) is notched by incorporating a complementary split ring resonator (SRR) slot within the hexagonal shaped . The operating frequency ranges of the proposed antenna are 2.22 GHz - 2.52 GHz and 3.5 GHz - 10 GHz, which covers Bluetooth (2.4 GHz - 2.484 GHz) and UWB (3.1 GHz - 10.6 GHz) band, besides the range of Wlan (5.72 GHz - 5.825 GHz) with return loss more than 10 dB. The performance of the antenna is simulated and optimized by CST Microwave Studio and validated against using Ansoft HFSS . Surface current distributions is used to analyze the effects of the slot and strips. The antenna shows an acceptable gain over both Bluetooth and UWB bands. In the band notched regions, the gain reduces from its normal value to about 4 dBi at 5.75GHz.

Compact antipodal Vivaldi antenna with rectangular slots and shaping of flare to cover 6 to 18 GHz

ABSTRACTThe compact antipodal Vivaldi antenna (AVA) with regular rectangular slots in the taper region is presented in this paper intended for electronic warfare applications. The antenna has a simple configuration with compact size. Micro strip line feeding is employed. The rectangular slots at regular intervals and terminal elliptical shaping of taper on top and bottom layers of antenna substrate enhance impedance bandwidth. The slot loading in the taper portion also enhances the gain. The novel feature of this antenna is its small aperture size which is 25 mm. Small aperture size is required for array applications to avoid grating lobes and element pattern nulls. A return loss of less than −10 dB (VSWR <2.0) is obtained over 6 to 18 GHz. The antenna is designed using Ansoft HFSS software and the same is implemented in hardware. Return loss, radiation patterns, and gain have been measured and results reported.

A Wideband V-Shaped Coplanar Patch Antenna for 2-6 GHz Designed for Energy Harvesting and Wireless Communications

This article portrays a compact wideband coplanar-fed V-shaped antenna. It has been designed for harvesting energy from wireless local area networks (IEEE 802.11) and other wireless communication systems covering the 2–6 GHz frequency band. The Structure of this antenna comprises a rectangular patch and an isosceles trapezoid. A V-shaped slot is introduced on the rectangular patch in order to perturb the surface current path which contributes to the formation of the wide-band characteristics. A trapezoid is inserted between the coplanar feed and the patch for the purpose of impedance matching and resonance shifting. A parametric study has been carried out to understand the effects of various dimensional parameters and to optimize the performance of the antenna. The measurement results which are in agreement with Ansoft HFSS simulation results, showed an agreeable bandwidth and satisfactory characteristics for omnidirectional radiation.

Design of a Compact High Gain Microstrip Patch Antenna for Tri-Band 5 G Wireless Communication

Abstract In this paper, a Tri-band microstrip-line-fed low profile microstrip patch antenna is proposed for future multi-band 5 G wireless communication applications. The proposed antenna is printed on a compact Rogers RT5880 substrate of dimensions 20×16.5×0.508 mm3 with relative permittivity, εr of 2.2 and loss tangent, tan δ of 0.0009. To improve return loss and bandwidth of the proposed antenna, a partial ground plane technique is employed. The proposed antenna operates at 10, 28, and 38 GHz, three of the selected frequencies which are allocated by the International Telecommunication Union (ITU) for 5 G mobile communications. To reduce interference between the 5 G system and other systems in the band, a pair of T-shaped slots is etched in the radiating patch to reject unwanted frequency bands. The proposed design provides a gain of 5.67 dB at 10 GHz, 9.33 dB at 28 GHz and 9.57 dB at 38 GHz; the radiation pattern is mostly directional. The proposed antenna is designed and optimized using two commercial 3D full-wave software, viz. CST microwave studio and Ansoft HFSS. A prototype of the designed antenna that was fabricated and showed good agreement between the actual measurements of S11 &amp; VSWR and the simulation results using both software.

S-Shaped Metamaterial Ultra-Wideband Directive Patch Antenna

Antenna parameter optimization using S-shaped metamaterial embedded in antenna substrate is elucidated in this paper. Upon incorporation of proposed metamaterial array inside the antenna substrate, the bandwidth of antenna increases by 74% and directivity by about 11%. Results obtained are in good coherence when using the FEM based Ansoft HFSS simulation and MATLAB programming based on CAD formulas using the equivalent circuit analysis of patch antenna. The evolution of ‘S-shape’ has been explained beginning from the primitive Single Split Ring Resonator’s shape. The proposed structure was fabricated and nearly 6% deviation was obtained in comparison with the simulation results. This metamaterial antenna overcomes the low bandwidth limitation of patch antenna and helps in maintaining a low profile by obtaining 81% miniaturization.

Microstrip Line Fed Fractal Monopole Antenna with Defected Ground Structure

This paper presents a wideband polarized antenna that is designed and analyzed for the cellular communication applications. The proposed antenna is designed with the coplanar wave guide feeding (CPW) by using the RT/ duroid 5880 material with a dielectric constant 2.2. It is observed that in the proposed model the return loss is -21.40dB for ungrounded CPW where as for the grounded CPW the loss is reduced to -39.13dB. The gain for the ungrounded CPW fed antenna is 2.95 dB and is enhanced to 3.2dB with grounded CPW structure. It is observed that there is an improvement in the bandwidth upto 6.03 GhZ for grounded CPW when DGS is applied. The antenna designing and simulation is done using ANSOFT HFSS software.