High Frequency Structure Simulator Software Research Articles

High-resolution probe design for measuring the dielectric properties of human tissues

BackgroundIn order to use the microwave to measure the dielectric constant of the human body and improve the measurement resolution, a small near-field probe working at 915 MHz is designed in this paper.MethodBased on the electric small loop antenna model loaded by the spiral resonator (SR), a small near-field probe was designed. The probe model is designed and optimized by the HFSS (high frequency structure simulator) software. The human tissues were tested by the manufactured probe and the relationship between the S11 parameters of the probe and the human tissues was analyzed.Results and conclusionsA probe with small size was designed and fabricated, with the overall size of 10.0 mm × 12.0 mm × 0.8 mm. The probe has a good performance with a 30.7 dB return loss, a 20 MHz bandwidth at the resonance point, and a distance resolution of 10 mm. Due to the small size and good resolution of the probe, it can be used in the measurement of human tissues.

Multilayer co-fired microwave dielectric ceramics in MgTiO3-Li2TiO3 system with linear temperature coefficient of resonant frequency

To address the nonlinear variation of resonant frequency in a MgTiO3-CaTiO3 system over a wide temperature range (-40–105°C), MgTiO3-Li2TiO3 system ceramics with multilayer architectures are designed. Trilayer MgTiO3-Li2TiO3-MgTiO3 ceramics (mass ratio=0.2:0.56:0.2) sintered at 1275°C possess a linear and near-zero temperature coefficient of resonant frequency (τf+=-3.0 ppm/°C (25–105°C), τf-=2.7 ppm/°C (-40–25°C)). Compared with that of random distribution-type MgTiO3-Li2TiO3 ceramics, the Q × f value of trilayer ceramics is significantly improved (Q × f=80,000 GHz (@7.6 GHz)). The electric field distribution is examined by the eigenmode solver of High Frequency Structure Simulator software to analyze the effect of the Li2TiO3 content and the stacking scheme on the dielectric properties. The cross-sectional morphologies show a dense intermediate layer formed by ion diffusion, which acts as a glue to bond each layer. This work can be conceived as a new strategy for developing 5G wireless communication components with linear temperature-related resonant frequency (-40–105°C) and low dielectric loss.

Influence of Li2MoO4 and polytetrafluoroethylene addition on the cold sintering process and dielectric properties of BaBiLiTeO6 ceramics

Composites of BaBiLiTeO6 (BBLTO) - Li2MoO4 (LMO) and BaBiLiTeO6 - polytetrafluoroethylene (PTFE) were fabricated using cold sintering process and their microwave dielectric properties were investigated for the first time. Phase purity and reactivity of the composites were studied using XRD and vibrational spectroscopy. Influence of filler content, sintering duration and temperature on the density and dielectric properties of the composites were studied. Both BBLTO-LMO and BBLTO-PTFE composites exhibit dense microstructures at optimized sintering conditions. Broadband (10 MHz–1 GHz) dielectric response shows that relative permittivity (εr) and dielectric loss (tanδ) of composites are in the range of 9–16 and 0.02–0.11 respectively and the experimental relative permittivity is compared with theoretical models. A microstrip patch antenna based on BBLTO - PTFE composite was designed using High Frequency Structure Simulator (HFSS) software and the fabricated antenna radiates at 2.88 GHz with a return loss of −26.8 dB and impedance bandwidth of 90 MHz.

Notched Integrated Planar Antenna for UWB Application

A new ultra-wideband antenna (UWB) with band notch characteristics has been studies in this work. The propose structure has constructed using air gap between two layer, defected ground structure (DGS) and shorting post. The structure covers frequency ranges from 4.61 GHz to 9.85 GHz. The radiation pattern is quite stable throughout the whole operating range. The antenna operates in C band of frequency spectrum and provides wide impedance bandwidth of 72%. 5.5GHz frequency has been notched and an average gain around 5.8 dBi has been achieved which is very useful for enormous data handle in modern wireless communication. All the simulation has been carried out using High Frequency Structural Simulator (HFSS) software.

Gain Enhancement of Microstrip Patch Antenna by Using Novel Air Substrate With U-slotted Patch

Aim: In this work a Rectangular Microstrip Patch Antenna is designed by replacing conventional substrate with Air substrate and by adding a U shaped slot in Patch for Gain Enhancement. Materials and Methods: The Microstrip Patch Antenna with Air Substrate is used with 20 samples in comparison with FR-4 substrate of 2mm thickness. Results: Simulation is done by using Ansoft HFSS (High Frequency Structure Simulator) software. The performance of the Antenna is analyzed in terms of Gain, Directivity, Return loss, VSWR and enhancement in Gain is by 1.724 dB in comparison with FR-4 substrate. Attained Significance accuracy ratio (< 0.05). Conclusion: Microstrip Patch Antenna with Air substrate and U Slotted Patch performs better in terms of Gain.

Microstrip rectangular patch antenna using coplanar parasitic rod elements with substrate integrated feeding line technique

Microstrip antenna technology is fast growing technology in present days there are broadly used in mobile communication and satellite communication. The microstrip antennas are very low cost and low profile and ease fabrication. However, the bandwidth utilization is the drawback for this system. Now proposed methodology can be reduced that drawback and provide efficient bandwidth utilization factor in proposed method design a microstrip rectangular patch antenna using co-planar parasitic rod elements with substrate intergrading feeding line technique. This proposed method, microstrip rectangular patch antenna is designed for the enhancement of bandwidth, Improvement in front to back ratio, reduction in losses and high-quality factor and power handling capability. The proposed method enhances the bandwidth ratio from 4% to 18% it shows that the proposed method gives the best results compared to the existing approach. The simulation and 3D plot results can be obtained from Ansoft HFSS (High-frequency structure simulator) Software.

Design and Analysis of a Radio-Frequency Moisture Sensor for Grain Based on the Difference Method.

Grain moisture is one of the key indexes of grain quality, and acquiring an accurate moisture value is critical for grain storage security. However, the sensors used in the traditional methods for testing grain moisture are based on capacitance, microwave, or radio-frequency methods and still exhibit low accuracy and instability because they are susceptible to the temperature, moisture, and micro gas flow of the air in the granary. In this study, we employed a new design for a radio-frequency moisture sensor for grain. The structure of the sensor is based on the difference method and consists of two parallel probe units. These units are at different distances to the tested grain, resulting in different sensitivities in the moisture measurements. Through a phase difference operation on the test signals, the disturbance variable was reduced. The specific size of the two parallel probes was confirmed by calculation and simulation using High Frequency Structure Simulator (HFSS) software. The simulated and measured parameters of a prototype sensor agreed well. The linear relationship yielded a correlation coefficient of 0.9904, and the average error of the moisture testing was within ±0.3% under the conditions where the VSWR (voltage standing wave ratio) value and return losses were 1.5896 and −20 dB, respectively, at a measured central frequency of 100 MHz. The results indicate that the performance of the sensor was excellent.

Comb Shaped Triple Band Microstrip Antenna for Wireless Communication

A comb shaped microstrip antenna is designed by loading rectangular slots on the patch of the antenna. The antenna resonating at three different frequencies f1 = 5.35 GHz, f2 = 6.19 GHz and f3= 8.15 GHz. The designed antenna is simulated on High Frequency Structure Simulator software [HFSS] and the antenna is fabricated using substrate glass epoxy with dielectric constant 4.4 having dimension of 8x4x0.16 cms. The antenna shows good return loss, bandwidth and VSWR. Experimental results are observed using Vector Analyzer MS2037C/2.

Design of Frequency Reconfigurable Patch Antenna for Sensing and Tracking Communications

This paper presents a front-end structure of a reconfigurable patch antenna for cognitive radio systems. The antenna structure consists of an Ultrawideband (UWB) sensing antenna and an array of frequency reconfigurable antennas incorporated on the same substrate. The UWB and reconfigurable antennas are fed by co-planar waveguides (CPW). The reconfigurability is achieved by rotating the series of patch antennas through a certain angle and the rotation is controlled by mechanical means using an Arduino microcontroller. The rotational reconfigurability has been preferred over MEMS switches, PIN diodes, and other lumped elements because the latter requires the need for bias lines. The entire structure is designed using High Frequency Structure Simulator (HFSS) software and the prototype is fabricated over FR-4 substrate having a thickness of 1.6mm and measurements are carried out. This antenna achieves a wideband frequency from 2 GHz to 12 GHz and distinct narrow band of frequencies by reconfigurability using single antenna consisting of different shapes spaced accurately to ensure isolation between adjacent frequency bands and each antenna element working for a bandwidth of 2 GHz for frequency from 2 GHz to 12 GHz upon a single substrate and the reconfigurable elements are controlled using a low cost Arduino microcontroller connected directly to the antenna which ensures accurate controlling of the rotation and fast switching between the antenna elements. The measured results agree with the simulated results and have less than 10 dB impedance bandwidth.

A Wide Beam Printed Quadrifilar Helix based Circularly Polarised Radiating Element for Electronically Steered Antenna

Wide beam and low axial ratio performance of printed quadrifilar antennas result in very attractive circularly polarised radiating element for wide scanned Electronically Steered Antenna. A compact printed quadrifilar Helix antenna (PQHA) has been designed and realised at S-Band frequency. Simulation and optimisation of designed antenna has been performed using ANSYS’s high frequency structure simulation (HFSS) software for its impedance, axial ratio (AR) performance and radiation characteristics. The developed circularly polarised antenna has 3-dB beam width of 130° and peak gain of 3.4dBic at 2.6 GHz. The developed antenna shows excellent AR performance over the frequency band as well as over the radiated beam. Half power axial ratio bandwidth of developed antenna is 27.4% (2.2 GHz - 2.9 GHz) while the impedance bandwidth is 32% (2.1 GHz - 2.9 GHz). Design has been validated through measured results. Designed wide band PQHA can be used as radiating element for electronically steered antenna for large beam steering application.

MINKOWSKI LOOP ANTENNA FOR 5G MOBILE COMMUNICATION

5G or fifth generation of cellular technology, is the successor of 4G LTE. It focusses on high date rate, high system capacity cheaper cost. Although it is still a maturing technology, the countries around the world have already stared implementing of on experimented basis. Massive connectivity is at the core of 5G and thus aim to get different components around us connected to each other. The paper focusses on minkowski loops fractal structures till 2nd iteration making a simpler and cheaper antenna for 5G application of cellular technology. The main feature of this antenna is that it occupied the same space as a regular pattern antenna, but offers a far bigger length for radiation. The resonant frequency taken is 30GHz. The substrate taken is RT-Duriod 6006 with dielectric constant 6.45. The antenna has been designed, simulated and analyzed using the software high frequency structure simulator.

A Design for the Quad Band pass Filter Using a Stub Loaded Resonator Technique

Band pass filters are widely used in wireless transmitters and receivers. A compact Quad band pass filter with stub loaded technique has been designed in this paper. HFSS (High Frequency structure simulator) software is used for the designing purpose. By the help of this technique four (quad) pass band pass filter has attained. The filter has an insertion loss of 0.8663, 8.1760, 3.0527, 3.8269 and located at 0.7, 1.31, 1.9, 4.2 GHz. The calculated return loss are 19.5, 9.04, 15.8, 19.7 dB.

Microstrip rectangular patch antenna using coplanar parasitic rod elements with substrate integrated feeding line technique

Microstrip antenna technology is fast growing technology in present days there are broadly used in mobile communication and satellite communication. The microstrip antennas are very low cost and low profile and ease fabrication. However, the bandwidth utilization is the drawback for this system. Now proposed methodology can be reduced that drawback and provide efficient bandwidth utilization factor in proposed method design a microstrip rectangular patch antenna using co-planar parasitic rod elements with substrate intergrading feeding line technique. This proposed method, microstrip rectangular patch antenna is designed for the enhancement of bandwidth, Improvement in front to back ratio, reduction in losses and high-quality factor and power handling capability. The proposed method enhances the bandwidth ratio from 4% to 18% it shows that the proposed method gives the best results compared to the existing approach. The simulation and 3D plot results can be obtained from Ansoft HFSS (High-frequency structure simulator) Software.

Design, Analysis, and Optimization of the Array of Axial Rectangular Slots on a Cylindrical Waveguide

In the current work, for the first time, the design equations for an array of rectangular slots axially placed on a cylindrical waveguide are driven and presented, making it possible to attain asymmetrical and non-broadside patterns with higher bandwidths. The method of least squares is then used for both the radiation pattern synthesis with the specified side lobe level and the array input impedance matching. For optimization, the error function comprised of the three terms of impedance matching, array pattern synthesis, and slot design equations is constructed. To minimize the error function, the genetic algorithm combined with the conjugate gradient method is utilized and the geometrical characteristic of the slots defined. This procedure increases the design speed and provides the means to synthesize any desired pattern for an array of axial rectangular slots on a cylindrical waveguide. Numerical and fabrication examples are presented as illustrations of the proposed synthesis method. The results of the proposed method are verified by using the commercial software High-Frequency Structure Simulator (HFSS) in comparison to measurement results obtained out of the proposed prototype of a fabricated antenna operating at the frequency of 9 GHz.

Hybrid Full-Wave Analysis of Surface Acoustic Wave Devices for Accuracy and Fast Performance Prediction.

In this paper, a hybrid full-wave analysis of surface acoustic wave (SAW) devices is proposed to achieve accurate and fast simulation. The partial differential equation (PDE) models of the physical system in question and graphics processing unit (GPU)-assisted hierarchical cascading technology (HCT) are used to calculate acoustic-electric characteristics of a SAW filter. The practical solid model of the radio frequency (RF) filter package is constructed in High Frequency Structure Simulator (HFSS) software and the parasitic electromagnetics of the entire package is considered in the design process. The PDE-based models of the two-dimensional finite element method (2D-FEM) are derived in detail and solved by the PDE module embedded in COMSOL Multiphysics. Due to the advantages of PDE-based 2D-FEM, it is universal, efficient and not restricted to handling arbitrary materials and crystal cuts, electrode shapes, and multi-layered substrate. Combining COMSOL Multiphysics with a user-friendly interface, a flexible way of modeling and mesh generation, it can greatly reduce the complicated process of modeling and physical properties definition. Based on a hybrid full-wave analysis, we present an example application of this approach on a TC-SAW ladder filter with 5° YX-cut LiNbO3 substrate. Numerical results and measurements were calculated for comparison, and the accuracy and efficiency of the proposed method were verified.

A triple band modified F-shaped monopole antenna for RFID application

Radio frequency identification (RFID) is a very prominent technology and is used in object-attached identification and tracking tags. In this paper a triple band monopole antenna is designed to work at 2.2-2.6 GHz (lower RFID band), 5.3-6.8 GHz and 8.7-9.5 GHz (upper RFID band) frequency ranges. The antenna design resembles a modified F-shaped radiator and is built on a low cost easily available FR4 dielectric substrate. Initially an F-shaped radiator with partial ground plane is studied which exhibits the operation at 2.6 and 6.5 GHz. Further, modifying this F-shaped radiator exhibits an additional resonance at 9.2 GHz. Fundamental characteristics such as reflection coefficient (S11), radiation pattern and 3D gain have been analyzed and good results have been obtained. Parametric analysis is carried out to fix the optimized antenna dimensions. All the simulations are carried out using the high frequency structure simulator software (HFSS). The antenna structure is easy to design and produce, and ideal for use in RFID applications.document quickly and accurately, to determine its relevance to their interests, and thus to decide whether to read the document in its entirety.

Designing a Microstrip Patch Antenna in Part of Ultra-Wideband Applications

In this work, a simulated study was carried out for designing a novel spiral rectangular patch of microstrip antenna that is used in ultra-wideband applications by using a high frequency structure simulator software (HFSS). A substrate with dielectric constant of 4.4 and height 2.10 mm (commercial substrate height available is about 0.8-1.575 mm) has been used for the design of the proposed antenna. The design basis for enhancing bandwidth in the frequency range 6.63 - 10.93 GHz is based on increasing the edge areas that positively affect the antenna's efficiency. This design makes the designed antenna cost less by reducing the area of the patch. It has been noticed that the bandwidth of the antenna under this study is increasing to 4.30 GHz or 61% compared with 3.6% for the standard rectangular microstrip antenna with the same dimensions of the proposed antenna. The antenna also maintains the voltage standing wave ratio of 1.09 at resonant frequency 7.07 GHz, return loss -27.07 dB, and the amount of impedance in real and imaginary parts 51.5Ω and 3.3Ω, respectively.

Frequency Reconfigurable Slotted Split-Ring Antenna

Background & Objective: Partially grounded frequency reconfigurable antenna is discussed in this paper. Antenna frequency cover is 4.2 GHz to 7 GHz and it has reconfigurable notchband near 5 GHz frequency. Frequency rejection is achieved by using circular split-ring slots in radiating element. The antenna can be reconfigured at 5.1 GHz, 5.4 GHz and 5.9 GHz by creating more slots in outer most split-ring. Designed antennas are printed on FR-4, low-cost substrate having relative permittivity of 4.4 and thickness of 1.6 mm. Results & Conclusion: Simulation of antennas is carried out using High Frequency Structure Simulator (HFSS) software. Designed antenna has omni directional radiation pattern. The prototype antennas are fabricated and tested using network analyzer. Good matching is observed between simulated and measured results.

Antenna for microwave manipulation of NV colour centres

Nitrogen-vacancy (NV) colour centres in diamond have attracted extensive attention in quantum precision measurement, computation and communication. In these fields, microwave manipulation is a technology in which antenna is used to radiate special microwave to manipulate the quantum spin state of NV colour centres. In this work, high frequency structure simulator software is used to design a microstrip antenna with a resonance frequency of 2.8756 GHz. Based on simulation and experiments, near field radiation of antenna is optimised to improve its microwave manipulation quality. This antenna will be helpful in the development of hybrid quantum devices of NV centres.

5G Hairpin and Interdigital Bandpass Filters

At two low 5G frequency bands: 3.7 GHz - 4.2 GHz and 5.975 GHz -7.125 GHz, Hairpin Bandpass Filter (HPBF) and Interdigital Bandpass Filter (IBF) are designed and simulated in this paper. Both filters show good results in terms of matching and transmission responses with a wide bandwidth through the two frequency bands. HPBF with simple design resulted in good return and insertion losses, < - 10.43 dB and - 0.63 dB, and < -14.48 dB and -0.46 dB through frequency bands: 3.51 GHz - 4.27 GHz and 5.58 GHz - 7.24 GHz, respectively. In addition to good filter response that IBF provides, it supports high order second harmonics suppression. The simulated S11 and S12 of this filter are < -11.15 dB and -0.63 dB with out of band rejection up to 11.12 GHz through the frequency band 3.56 GHz - 4.25 GHz. Furthermore, at the second frequency band IBF is designed with two different grounding via hole radii (rVia), case 1: rVia = 0.4 mm and case 2: rVia = 0.7 mm. For both cases, the designed filter shows good results with high order second harmonics suppression up to 18.33 GHz and 18.96 GHz. In this paper, High Frequency Structure Simulator (HFSS) software is used to carry out the simulation.