Simulation Software HFSS Research Articles

Design, simulation and manufacture of a flexible frequency selective surface based on aramid/carbon fiber woven fabric

Frequency selective surfaces (FSSs) are significant for the efficient and accurate transmission of microwave signals due to its ability to selectively shield electromagnetic (EM) waves of different frequencies. In some special scenarios, mechanical properties are vitally required. Herein, a flexible frequency selective fabric (FSF) is proposed. Different from traditional FSSs or reported FSFs, aramid/carbon fiber woven fabric serve as the flexible substrate in which carbon fiber provides functionality instead of metallic materials, and patches made of carbon fiber prepreg are periodically applied for property reinforcement. Equivalent circuit model is used to guide the basic determination of patch’s geometry, and it is further optimized via full-wave simulation software HFSS. A simulation model that reasonably reflect the correlation between structure and frequency-selection characteristic is provided, and structural factors affecting the characteristic are analyzed and discussed. Further, an FSF sample is prepared and its frequency response is measured. Measurement revealed the FSF selectively shields EM waves in the frequency range of 8.9 GHz to 11.4 GHz, and is of the bandpass-bandstop-bandpass characteristic. Benefit from EM property and flexibility, the proposed FSF has advantages in applications pursue lightweight, high strength, and require excellent EM functionality, such as aerospace and structure-EM function integrated products.

Design and preparation of L-band multilayer low-group delay filter based on inner sputtering

Article propose a design for an L-band multi-layer MEMS cross-finger filter based on pore interior wall sputtering. Article analyze the structural parameters, such as resonator thickness and TSV structure, using HFSS simulation software. Findings indicate that the filter has a central frequency of 1.5 GHz, a bandwidth of 140 MHz, a band loss of less than 1 dB, return loss is greater than 25 dB, and a band group delay of less than 800 ps. Furthermore, Article conduct process design optimization and finished product testing for the filter, including optimizing the TSV process for the hole inner wall sputtering process. These results demonstrate the filter's broad application prospects.

Design of multi-band flexible microstrip antenna based on micro drop jetting

Due to the high compatibility of micro-droplet jetting 3D printing technology within the realm of printed electronics, a flexible and miniaturized multi-band microstrip antenna was designed. The purpose of this is to extend the wireless signal response range of wearable devices and to investigate the feasibility of producing wearable devices with high efficiency. The antenna uses polydimethylsiloxane (PDMS) as the dielectric substrate and nanosilver as the conductive material for the radiating patch, demonstrating remarkable flexibility. The antenna’s structure underwent simulation and analysis through frequency sweeping using ANSYS HFSS simulation software. The outcomes illustrate the antenna operating within three frequency bands at 2.5GHz, 3.5GHz, and 5.8GHz, and the return loss is kept below -18dB for each central frequency. Simultaneously, it displays favorable flexibility. The radiation pattern of the antenna indicates that it has good directivity and no extra side lobes are generated. Ultimately, Antennas were fabricated using microdroplet spraying technology, and the final product’s characteristics and morphology were analyzed. The aforementioned findings demonstrate that micro-droplet jetting technology’s remarkable precision and efficiency render it a viable approach for the processing and production of flexible microstrip antennas.

A single feed circularly polarized dual band microstrip monopole antenna for wireless applications

AbstractThe paper proposes a circularly polarized dual band single feed microstrip monopole antenna. The proposed antenna consists of a radiating patch, a shrink ground plane, and a 50 Ω microstrip transmission line feed. The radiating patch is a combination of three modified metallic strips, a modified rectangular strip and a semicircular strip. The ground plane consists of two modified open ended slots. The substrate area of the antenna is only 40 mm × 42 mm × 1.6 mm. The antenna has been designed by HFSS simulation software and after getting simulated results the antenna has been fabricated to verify its results. The antenna provides measured bandwidths (−10 dB impedance bandwidth) of 600 MHz (2.2–2.8 GHz) in the lower band and 2.1 GHz (7.5–9.6 GHz) in the higher band. The measured results show its 3 dB axial ratio bandwidth of 120 MHz (2.2–2.32 GHz) for lower band and 1.4 GHz (7.2–8.6) GHz for the upper band. The high measured peak gain of 8 dBi has been obtained from the proposed antenna. The lower band is useful for WiMAX application and upper band is useful for C band application. The desired radiation patterns (RHCP and LHCP) have been obtained from the proposed antenna.

Microwave resonant device for water content on-line measurement of lubricating oil

An on-line measurement device of water content in lubricating oil based on microwave resonance technology is presented. By utilizing finite-element analysis and high-frequency structure simulator software HFSS, a semi-hermetic resonator (22 mm in diameter and 25 mm in length) for this device is designed, and the measurement results are simulated. In the experiment, the resonance frequency is chosen as the measurement parameter, in which the frequency band is 9.302 ∼ 9.307 GHz. In the water content range of 0 to 500 ppm (by volume), the resonance frequency decreases linearly with increasing water content, which is consistent with the simulation. The sensitivity is 1 MHz per 100 ppm of water content, and the maximum error in water content is 33 ppm. With temperature compensation in the range of 15 °C to 25 °C, the measurement resolution of this device is better than 100 ppm.

Design of a graphene RF MEMS switch for X–V band

In this paper, we propose a graphene RF MEMS switch design for the X–V band. The structural parameters of graphene, such as the number of layers, the thickness of the medium and the material of the upper electrode, were analyzed by HFSS simulation software. The drive voltage of the switch was found to be as low as 3 V. The switching time is 320 ns. The highest isolation is −47.46 dB@8 GHz; In the 2–56 GHz band, the isolation is better than −20dB. Moreover, we carry out the process design of the switch, including key techniques such as graphene beam fabrication and graphene transfer, it shows that the switch has a great application prospect in the future.

Design and Analysis of a Low-profile Microstrip Antenna for 5G Applications using AI-based PSO Approach

Microstrip antennas are high gain aerials for low-profile wireless applications working with frequencies over 100 MHz. This paper presents a study and design of a low cost slotted-type microstrip patch antenna that can be used in 5G millimeter wave applications. This research focuses on the effect of ground slots and patch slots which, in turn, affect different antenna parameters, such as return loss, VSWR, gain, radiation pattern, and axial ratio. The working frequency range varies from 24 to 28 GHz, thus falling within 5G specifications. A subset of artificial intelligence (AI) known as particle swarm optimization (PSO) is used to approximatively solve issues involving maximization and minimization of numerical values, being highly challenging or even impossible to solve in a precise manner. Here, we have designed and analyzed a low-profile printed microstrip antenna for 5G applications using the AI-based PSO approach. The novelty of the research is mainly in the design approach, compactness of size and antenna applicability. The antenna was simulated with the use of HFSS simulation software.

Design of a Q-band waveguide to CPW transition

A design scheme of waveguide to co-planar waveguide probe transition structure is proposed in this paper, and the structure is modeled and optimized by Ansoft’s electromagnetic simulation software HFSS. The simulation results indicate that the structure’s reflection coefficient is below -20dB and its insertion loss is below -0.3dB at 38∼47GHz. The structure is applicable to tile-type T/R modules.

Prediction of Microwave Characteristic Parameters Based on MMIC Gold Wire Bonding

In this paper, a method based on deep learning is proposed to predict the parameters of bonded metal wires, which solves the problem that the transmission characteristics of S-parameters cannot be predicted. In an X-band microwave chip circuit, gold wire bonding technology is often used to realize bonding interconnection, and the arch height and span of the bonded metal wire will have a great influence on the microwave transmission characteristics. By predicting the S-parameters of the bonded metal wire, the relationship between the structure parameters of the single wire and the transmission performance of the microwave device can be deduced. First, the gold wire bonding model is established in HFSS simulation software. After parameter optimization, the simulation results meet the requirements of establishing data sets. Then the sampling range of S parameters is set, and the parameters are scanned to establish data sets. Second, the artificial neural network model is built. The model adds a dropout mechanism to the hidden layer to enhance the generalization of the neural network, prevent overfitting phenomenon, and significantly improve the model’s prediction performance. Finally, the model predicts the corresponding relationship between the arch height and span of the bonding wire and the insertion loss, return loss and standing wave ratio. The mean square error of the test set is less than 0.8. The experimental results show that compared with the traditional process measurement method, this method can quickly and accurately infer whether the microwave characteristics of the bonded product are qualified, which greatly reduces the time and economic cost of the engineer and improves the work efficiency.

A Miniaturized Low-Loss Switchable Single- and Dual-Band Bandpass Filter

In this paper, a novel switchable bandpass filter is proposed. By switching p-i-n diodes on/off, the proposed filter can be switched between the single-band bandpass filter and the dual-band bandpass filter. The filter is mainly composed of eight pairs of series LC resonators, which generate passbands and transmission zeros. Considering the requirement of miniaturization and low cost, the filter is realized by interdigital capacitors and microstrip section inductors. The layout is designed by 3D simulation software HFSS, and the active part is designed by ADS software. The proposed filter has a compact structure, and its size is only 22.20 mm × 25.66 m m. For a demonstration, a switchable bandpass filter has been designed, fabricated, and measured. The simulated and measured results have a good agreement.

Miniaturized six‐ring elliptical monopole‐based MIMO antenna for ultrawideband applications

SummaryThis paper proposes a miniature two‐element Multiple Input Multiple Output (MIMO) antenna dedicated to UWB applications. The proposed MIMO design has a very low profile of 30 × 20 × 1.6 mm3. The proposed antenna is carefully designed and optimized using HFSS simulation software. As a proof of concept, the proposed design is realized and experimentally tested for MIMO applications. The proposed structure, printed on an FR4 substrate, comprises two symmetrical elliptical conductive patches on the upper side and a modified ground plane on the lower one. Each radiating element includes six elliptical rings. The modified ground plane consists of a T‐shaped strip and two semielliptical slots etched opposite the feed line. All the parameters of the design are carefully optimized to achieve an ultrawide bandwidth antenna spanning from (136.08%) 3.1 to 16.3 GHz. The results are discussed and analyzed in terms of bandwidth, gain, efficiency, radiation pattern, diversity gain, envelope correlation coefficient (ECC), total active reflection coefficient (TARC), and mean effective gain (MEG). All simulated results are found to be in good accordance with experiments. The design reveals attractive features for UWB applications. A good isolation (17 dB) between the two radiators is achieved despite the close proximity using the suggested ground plane geometry.

Design of Novel Ultra-wideband Slow-wave Microstrip Transmission Line

Microwave passive devices with high efficiency, small size, and light weight are one of the fundamental requirements for mobile communication coverage in the 5G frequency band. In this paper, the design of a novel ultra-wideband slow-wave microstrip transmission line is proposed and studied. The electromagnetic field simulation software HFSS is used to simulate the slow-wave microstrip transmission line, and the simulation results show that the ultra-wideband slow-wave structure has the advantage of wider bandwidth, smaller size, and lower cost, which meets the needs of 5G communication systems. Finally, the proposed slow-wave microstrip line is used in the U-shaped phase shifter, and the experimental results show that the novel slow-wave microstrip transmission line has a large application potential in the base station antenna system.

Double-Split Rectangular Dual-Ring DNG Metamaterial for 5G Millimeter Wave Applications

This article presents the design and analysis of a low profile double-negative (DNG) metamaterial unit structure for 5G mmWave (millimeter wave) applications. The structure, comprised of double-slotted rectangular ring patches, experiences the peak current value near the magnetic resonance, causing the metamaterial to resonate at 28 GHz where it exhibits negative effective permittivity and permeability. The 3.05 mm × 2.85 mm compact structure is designed over a substrate Rogers RT/Duroid 5880 to attain better effective medium ratio (EMR) in the 5G frequency range (27.1–29.2 GHz). A rigorous parametric study is conducted to obtain the proposed design. Full-wave electromagnetic simulation software tools CST and HFSS are used to generate the scattering parameters for the analysis. The Nicolson–Ross–Wier method is used to observe the negative effective permittivity and permeability. In addition, different output quantities, e.g., surface current and electric and magnetic field distribution, are investigated. The structure is further tested with 1 × 2, 2 × 2, and 4 × 4 arrays, where the results show adequate agreement to be considered for 5G mmWave applications.

Detection Method Based on RFID Tag on the Metal Surface

In radio frequency identification (RFID) technology, RFID tags’ work on the metal surface is greatly affected by the metal, and the read/write distance and read rate of the tag will be reduced along with the change of the distance between the tag and the metal surface. Aiming at this feature, this paper studies and designs two kinds of metal-resistant UHF RFID micro-strip tags with a center frequency of 915MHz according to the “resonant cavity principle” and HFSS simulation software. After optimization, the size of the tag antenna is reduced. Through the distance expression and experiment, we verify the maximum recognition distance between the reader, and the tag can reach 3.46m, which can solve the problem of conventional RFID tags by metal interference.

Miniaturized Antenna for IOT Application

Ansys platform-based HFSS simulator software is used to create a 4GHz circular micro strip patch antenna array. Applications including Bluetooth, the Internet of Things, and several WLANs can all benefit from it. The circular patch antenna, which is constructed on a FR4 substrate with a dielectric constant of 4.4 and a height of 1.6mm, is fed using edge feeding. The antenna is built using a 1.4mm thick FR-4 (lossy) substrate with a relative permittivity of 4.4 and a microstrip line feed. The chosen radius for the circular patch is 7.62mm. To lower the size and enhance the performance of the suggested antenna, a square slit 30mm by 30mm in size is etched onto the ground plane. The HFSS Simulation Program is employed in the antenna's design. Antenna characteristics such as return loss, radiation pattern, bandwidth, orientation, antenna gain and radiated efficiency are all studied.

Design and implementation of LTCC coreless transformers for intelligent solid-state switch

This paper designs, manufactures, and evaluates a multilayer coreless low temperature coiffed ceramic (LTCC) transformer for solid state power controller (SSPC) applications. A series of circular spiral transformers with different layers and turns are fabricated in 2 ∼ 6 layers LTCC. The transformers are simulated and analyzed by using simulation software HFSS, in which the analysis results can be used for the design basis of transformers. The comparison results of these different transformers in terms of resistance, self-loss, Q-factor, mutual inductance, coupling coefficient, and energy efficiency are presented. The working area of the best performance of these transformers for SSPC application is determined, and the IDU used in SSPC implementation based on LTCC coreless transformer is completed.

Advance 3D FSS with several transmission zeros for S, C and X frequency

The advanced 3D Frequency Selective Surface (FSS) is intended from a 2D regular array of two guarded micro strip lines that comprise a single element cell. The designed 3D FSS exhibits elliptic band-pass responses for two frequency ranges (3.64–4.7) GHz and (7.65–9.6) GHz, which lie in the S, C, and X microwave frequency bands. The transmission zeros have been provided at 3.4 GHz, 5 GHz, 6.6 GHz, and 10 GHz frequencies to improvise the selectivity of the FSS filter. The FSS response is self-sufficient of the level signal until the angle of attack varies by 50°. Every element cell of the guarded micro strip lines consists of an air slot with a T-shaped metal sheet. When a TE contrasted level signal coincidences perpendicularly to the dual guarded micro strip lines, The air quasi-TEM mode along with the substrate quasi-TEM mode resulted. Transmission poles are obtained in phase resonating modes combinations, whereas transmission zeros are obtained in out of phase resonating modes combinations. The versatile ANSYS HFSS simulation software is used to plan and reproduce the proposed 3D FSS composition. The obtained outcomes show enhanced presentation of the above two-dimensional (2D) FSS composition with the designed 3D FSS finds numerous actual approaches like spatial filters, radomes, and antenna sub-reflectors.

Miniaturization of Microstrip Antenna Using Techniques of Meandering, Loading, and Bending Slots

One of the existing challenges while realizing miniaturization of the antenna is ensuring that the performance of the antenna without any negative effect has become the main focus of many researchers and pose challenges towards microstrip antenna research. In this paper, we focus on the study of miniaturization of microstrip antennas by designing miniaturized antennas, and carry out modeling and simulation. On basis of existing theory, the proposed method introduces the miniaturization technology of three mainstream microstrip antennas, namely meandering, loading, and bending slots. The electromagnetic simulation software HFSS is used to analyze the influence of the parameters of the three technologies on the antenna performance, and respectively propose a miniaturization scheme of the microstrip antenna.

Compact and Highly Sensitive Bended Microwave Liquid Sensor Based on a Metamaterial Complementary Split-Ring Resonator

In this paper, we present the design of a compact and highly sensitive microwave sensor based on a metamaterial complementary split-ring resonator (CSRR), for liquid characterization at microwave frequencies. The design consists of a two-port microstrip-fed rectangular patch resonating structure printed on a 20 × 28 mm2 Roger RO3035 substrate with a thickness of 0.75 mm, a relative permittivity of 3.5, and a loss tangent of 0.0015. A CSRR is etched on the ground plane for the purpose of sensor miniaturization. The investigated liquid sample is put in a capillary glass tube lying parallel to the surface of the sensor. The parallel placement of the liquid test tube makes the design twice as efficient as a normal one in terms of sensitivity and Q factor. By bending the proposed structure, further enhancements of the sensor design can be obtained. These changes result in a shift in the resonant frequency and Q factor of the sensor. Hence, we could improve the sensitivity 10-fold compared to the flat structure. Subsequently, two configurations of sensors were designed and tested using CST simulation software, validated using HFSS simulation software, and compared to structures available in the literature, obtaining good agreement. A prototype of the flat configuration was fabricated and experimentally tested. Simulation results were found to be in good agreement with the experiments. The proposed devices exhibit the advantage of exploring multiple rapid and easy measurements using different test tubes, making the measurement faster, easier, and more cost-effective; therefore, the proposed high-sensitivity sensors are ideal candidates for various sensing applications.

On‐chip miniaturized bandpass filter using gallium arsenide‐based integrated passive device technology

AbstractThe paper proposes a miniaturized bandpass filter (BPF) using gallium arsenide (GaAs)‐based integrated passive device (IPD) technology. The proposed filter is evolved from traditional third order BPF, and it achieves a wide operation frequency band covering three 5G sub‐bands including 3.4–3.5 GHz, 3.5–3.6 GHz, and 4.8–4.9 GHz. The performance of out‐of‐band rejection is improved by introducing three transmission zeros (TZs). As known, adding cross coupling and LC resonator are the general methods to improve out‐of‐band rejection. Therefore, the first TZ at 5.85 GHz is obtained at the upper sideband by adding a capacitive coupling between the source port and resonator 2, which is a cross‐coupling mode. According to the coupling matrix, the value of the added capacitance can be calculated and optimized. Another TZ at 2.36 GHz is occurred at the left side of passband as a serial LC resonator is connected in parallel with filter near the input port. The third TZ at 7.74 GHz is generated at the upper sideband due to a serial LC resonator connected in parallel with the load terminal of the filter. The values of components in LC resonators can be calculated, too. Finally, the whole filter is optimized in full‐wave electromagnetic simulation software HFSS. The proposed filter is fabricated and measured, and the results show that it has a wide −10 dB frequency band from 3.3 GHz to 4.9 GHz and a maximum insertion loss of 2.5 dB. In addition, it has a good frequency selectivity with a rectangular coefficient of 1.67 and out‐of‐band suppression higher than 20 dB in a wide stopband. The filter adopts compact placement and has a relative miniaturized electrical size of 0.298 , which is about 55% smaller than recently reported one.