In this paper, a new design of a highly isolated tri-band antenna for 5G and future 6G applications is proposed. The overall dimensions of the proposed antenna are just 56.4 × 36.6 mm2; moreover, it contains two monopole antenna units and a defective ground. The tri-band characteristics of the antenna are achieved by improving the single antenna patch structure. The structure is improved based on the original T-shaped decoupling structure to create a fence-shaped decoupling structure consisting of an improved T-shaped and an improved rectangular structure. This will greatly improve isolation by efficiently absorbing the coupling current. Therefore, the proposed antenna system is designed and tested to reach the 5G dual bands of 3.38 GHz-3.61 GHz, 4.51 GHz-4.96 GHz, and the future 6G band of 6.06 GHz-7.51 GHz. The results show that, relative to other antennas, this antenna has an isolation degree in the operating band greater than 13.1 dB. In addition, the antenna has good radiation characteristics and an acceptable envelope correlation coefficient.
This paper presents a novel fourth-order bandpass filter with high selectivity and out-of-band suppression based on equivalent magnetic side wall cavities (MSWCs). By loading a via hole into an MSWC to produce a zero mode as a non-resonating node and using the dual MSWC modes TEM001 and TE100 as resonant modes, a modified doublet with two poles and two transmission zeros (TZs) can be formed. Three types of frequency response, either quasi-elliptic or asymmetric, can be obtained and designed flexibly. The TZs can be located on both sides of the passband or both on just one side. The mechanisms for generating the TZs are analyzed, and the adjustment of the TZ positions is discussed. The proposed four-pole quasi-elliptic filter with four TZs is a cascade of two such doublets with two different types of asymmetric response. It has been fabricated and measured to validate the design. Comparison is made with some previous work on substrate integrated waveguide filters. The developed filter is free from radiation and relatively compact among high order filters with multiple adjustable TZs based on cascaded cavities of the substrate integrated waveguide type.
Moisture measurement in industrial applications, both in liquid and solid materials, presents a significant challenge. In the field of biofuels, this becomes even more critical. Among the various approaches developed for this purpose, indirect electromagnetic techniques have emerged as a valuable tool for accurately estimating moisture content. These techniques utilize the complex dielectric permittivity ε as an intermediary parameter, which is influenced by the water content in the material. As a first step toward this purpose, a 1''5/8 two-port coaxial transmission cell, developed at LNE-CETIAT, was studied to make dielectric measurements on liquids. Characterization and validation steps were requested to demonstrate the accuracy of this cell. For this purpose, an intra-laboratory comparison has been performed first at LNE-CETIAT using the 1''5/8 cell and the EpsiMu® coaxial cell - a fully validated reference tool. Then, an inter-laboratory comparison with the Fresnel Institute has been performed using a coaxial probe and another EpsiMu®cell. The measurements were carried out under identical ambient conditions, using liquid reference materials. In this work, the performance of the developed cell in the frequency band [0,1-1,1] GHz has been validated, as well as the accuracy of the three electromagnetic techniques used. The results of the experiments confirm the effectiveness of the 1''5/8 cell developed at LNE-CETIAT for measuring the dielectric properties of liquids.
The main challenges of designing an antenna for modern wireless communication are size reduction and mutual coupling. An ultra-wideband (UWB) multiple input multiple outputs (MIMO) antennae with four elements is suggested by this paper. Each element has two ports with dual-polarized patches to reduce the result of reciprocal coupling, increase the capacity, and keep a proper size. A circular geometric shape is in front of the patch of the proposed antenna to reduce the impact of mutual coupling. The CST STUDIO 2019 program simulates the single antenna element and MIMO antenna using the four integrated elements, eight integrated ports, and an Fr-4 insulating layer in an area of (70 x 70) mm2. The MIMO antenna's operating frequency, which has a band of 2.85 (3.15-6) GHz at -10 dB, is 3.67 GHz while the operating frequency of a single antenna element, which has a band of 2.8 (3.1-5.9) GHz at -10 dB and a resonance return loss of -36 dB, is 3.64 GHz. The MIMO antennas obtained a diversity gain (DG) of about 10 with a good gain of about 8 dB while the envelope correlation coefficient (ECC) was equal to or less than 0.0001.
A hexagon-shaped fractal ultra-wideband (UWB) Multiple Input Multiple Output (MIMO) antenna is proposed in this paper for S (2 GHz to 4 GHz) and C (4 GHz to 8 GHz) band applications. The proposed design consists of two microstrip fed radiating elements of dimension 82 × 44 × 1.6 mm3. One rectangular stub and four resistance loaded stubs are introduced in the ground plane to reduce the mutual coupling between the radiators. These decoupling structures reduce the notches and enhance the isolation from -5 dB to -20 dB for the entire frequency range from 2.3 to 7.4 GHz. The performance characteristics and diversity parameters are also investigated which show the values of ECC < 0.004, DG > 9.96, CCL < 0.4 and MEG < 3 dB, and it is concluded that the proposed design is a good candidate for UWB MIMO. The proposed design is fabricated and tested which shows the close agreement between the simulated and measured results.
In order to solve the problem of the influence of magnetic saturation and voltage source inverter (VSI) nonlinear factors on the parameter identification of permanent magnet synchronous wind generator (PMSWG), a variable neighborhood search-adaptive genetic algorithm (VNS-AGA) based on magnetic saturation and VSI compensation is proposed in this paper. Considering the existence of magnetic saturation, a mathematical model of PMSWG considering magnetic saturation is established. The least square method is used to identify the inductance of dq axis. The influence of VSI nonlinear factors on the system is regarded as a disturbance voltage, which is used as an electrical parameter; the parameters of PMSWG are identified simultaneously; and voltage compensation is carried out. After the accurate distortion voltage compensation mathematical model and fitness function are established, GA and adaptive algorithm are combined to increase the diversity of the population. Then variable neighborhood search (VNS) strategy is introduced to search the optimal region. Experimental results show that the proposed method is more accurate and convergent after considering magnetic saturation and on-line identification and compensation of disturbance voltage.
This paper proposes a coplanar L-strip feeding technique to excite the dominant transverse electric (TE) mode in a rectangular microstrip patch antenna. To excite the TE mode, the patch and ground layers are composed of artificial magnetic conductor (AMC) unit cells, and the L-strip is fashioned so that it is coplanar with the AMC patch layer. Two TE-mode microstrip patch antennas are full-wave analyzed and fabricated, one in which the AMC patch is centered with respect to the ground plane and one in which the AMC patch is shifted laterally with respect to the ground plane to improve radiation pattern symmetry. Results from the fabricated antennas are discussed and compared to the simulations. The proposed antennas successfully excite the dominant TE10 mode while having at least 11% impedance bandwidth, 8 dBi gain, and stable broadside radiation patterns.
The paper proposes a antenna design that can serve as a comprehensive solution for covering 4G/5G cellular bands 850-1000 MHz, 1900 MHz, 2100-2700 MHz, 3300-4900 MHz, Global Navigation Satellite System (GNSS-L1) Band 1.56 GHz-1.61 GHz, V2X 5.850-5.925 GHz band which are appropriate for use in automobile applications. The proposed antenna is designed with respective polarization for cellular and GNSS applications, where the cellular antenna is linearly polarized, and the GNSS antenna is circularly polarized by chamfering the square patch. FR4 substrate material is used to construct the Long Term Evolution/4G (LTE) antenna. The optimization of the antennas ensures minimal coupling between them. The cellular antenna is designed using a hexagonal base with a modified ground plane to achieve the required cellular bands using a monopole (fractal design). The GNSS antenna is implemented on a PVC (Poly Vinyl Chloride) substrate. The measured results of S11 parameter show that the proposed design covers all the required 4G/5G bands with minimum S11 of -10 dB and a radiation pattern in the theta 60-90° range for cellular antenna, while the GNSS antenna has a zenith radiation pattern with axial ratio of <3 dB for theta angles in the 0-30° range and a mutual coupling of -15 dB. The fabricated antenna was measured to validate the simulated results of reflection coefficient, VSWR. All things considered, the suggested design is perfect for automobile applications to satisfy both satellite and mobile communication needs.
In this article the design of an ultra-wideband coplanar monopole antenna with a microstrip parasitic patch having a dimension of 50 mm x 50 mm using a 1 mm thick RT-Duroid substrate (εr = 2.2) is explored for wireless applications. Five different coplanar antenna designs are presented, and one of the designs is proposed for fabrication. In simulation the proposed antenna has four resonant bands, 2.043-2.133 GHz, 5.821-7.89 GHz, 10.3-12.027 GHz, and 12.783-17.802 GHz, with a cumulative bandwidth of 8.905 GHz within 1-18 GHz. The proposed antenna is fabricated, tested and validated using Vector Network Analyzer. Fabricated antenna resonates at four different bands, 2.349-2.888 GHz, 5.767-7.926 GHz, 9.725-10.534 GHz and 13.862-16.021 GHz with resonant peaks at 2.529 GHz, 7.116 GHz, 10.084 GHz and 15.391 GHz frequencies respectively. Further the antenna has a cumulative Bandwidth of 5.666 GHz in 1-18 GHz band. Radiation efficiency is above 90% at the resonant band. The acquired results from simulation and measurement are in close match.
This paper presents a low-profile, stub-loaded multi-slot antenna that operates across 850 MHz to 4500 MHz. Remarkably, the new design meets the call of covering wideband frequencies used by many 4G and 5G New Radio bands from UHF to C bands. The antenna consists of two wide slots on the ground plane. Each slot comprises a straight segment connected to a larger circular slot. A novel microstrip feed line loaded with dual circular stubs excites the multi-slot antenna. The slots and the feed lines are printed on each side of the dielectric substrate. This novel design offers pattern diversion capacity based on port excitation. Two prototypes were fabricated and tested to verify multiple simulation results including bandwidth, isolation, and group delays. A close consistent of measured and simulated results validates the design. Concurrently, good isolation between ports and nearly omnidirectional gain patterns are observed over the band. Further, the form factor of the proposed antenna makes it a suitable solution for modern 4G and 5G handheld devices.
In this paper, an artificial neural network (ANN) based approach is proposed for the estimation of the target angle using Multiple Input Multiple Output (MIMO) radars operating in Frequency Modulated Continuous Wave(FMCW). The proposed technique operates in two stages, with the first stage being the formation of the range profile at each MIMO element via Discrete Fourier Transform (DFT) and the second stage being the estimation of the target azimuth angle via an artificial neural network. The range profile formed in the first stage is fed to the second stage as a single snapshot angle measurement. The performance of the proposed technique is apprised with other existing methods under different Signal-to-Noise Ratio (SNR) conditions and measurement model uncertainties. The simulations performed show that the learning capability of the model strongly hinges on SNR conditions, and the learning process is ameliorated as SNR in training data increases as anticipated. Under low SNR conditions, the proposed technique performs better than other techniques in terms of Mean Square Error (MSE). We have also shown that our solution remains unaffected by the model uncertainties as it fully relies on the calibration data, while the performance of the model-based angle estimation techniques dramatically degrades as the uncertainty in the underlying model grows.
This paper presents the study of an H- and dual C-shaped planar dipole antenna by adding and etching technique for the triple-band of drone operating frequencies. Tuning the frequency range was performed to cover the VOR standard of 108-118 MHz, the GS standard of 328.6-335.4 MHz and the DME standard of 962-1,231 MHz. The antenna structure was fabricated on a PCB of FR4 with a dielectric constant (εr) of 4.4 and thickness (h) of 1.6 mm (material with low cost, compact size, and easy to use). The reflection coefficient (S11) results of the simulation and measurement were in good agreement, which demonstrated the bandwidth frequencies of resonance frequency at 112 MHz (106-118 MHz), 331.50 MHz (323-401 MHz), and 1,087.50 MHz (920-1,301 MHz). The antenna gains were 1.73, 3.43, and 6.31 dBi, respectively, and the antenna radiation pattern was omnidirectional when it was used with H-plane. It was found in experiment that the proposed antenna could be installed in a drone with sending and receiving signals fittingly as desired. Furthermore, the proposed antenna is lightweight at just 0.4 kg, less than the original drone antenna (1.8 kg), and it does not require changing the antenna in each frequency range.
3D printing is revolutionizing manufacturing and is now being considered in the electronics industry. The creation of the first 3D volumetric circuit (3DVC) has created a way to make circuits smaller, lighter, into unconventional form factors and exploit physics like anisotropy more effectively than planar geometries can. While this is exciting, many problems mustbe solved to make 3DVCs a reality. One of these problems is electromagnetic interference and mutual coupling between components that are expected to be highly problematic in high-frequency 3DVCs. Spatially-variant anisotropic metamaterials (SVAMs) could be a solution to overcome this difficulty, but research in this area is not possible without a way to generate SVAMs around multiple components. In this paper, an algorithm is integrated into CAD software that can generate SVAMs for 3D circuits which will enable future studies of SVAMs.
In this paper, a low-profile miniaturized microstrip monopole antenna with an overall size of 15 mm × 20 mm × 1.6 mm is developed and analyzed for Ultra-Wide Band (UWB) services. The proposed antenna is carefully designed, optimized and analyzed using HFSS 15 simulation software. A prototype of the design is realized and experimentally tested as proof of concept. The results are discussed and compared with literature. They show attractive radiating features for UWB applications. The proposed antenna consists of an elliptical patch printed on a low-cost FR-4 epoxy substrate with a modified ground plane. To achieve UWB characteristics, elliptical rings are etched on the conducting patch, and the ground plane is modified by adding an inverted L shaped strip and creating a semi-elliptical slot in the partial ground opposite to the feed line. The achieved ultra-wide band ranges from 3.1 to 18.1 GHz (141.51%).
This paper describes the design, fabrication, and test of a printed planar log-periodic dipole antenna to be used as a standard gain antenna in simple, low frequency, anechoic chamber far-field antenna measurements. The design procedure is size constrained by the photolithographic printing circuit fabrication process. Maximum gain and an input reflection coefficient below -10 dB are envisaged for the frequency range 0.5-2.5 GHz. The antenna is printed on a low cost FR4 substrate, and a careful analysis, with optimization of all the antenna physical parameters namely: number, length, spacing and width of the dipoles, width of the feed line traces, feed line termination, feed balun, and substrate shape, is carried out. The good agreement obtained between numerical simulation and experimental results provides validation of the proposed antenna configuration and design procedure.
This paper presents a miniaturized super wideband (SWB) antenna that has a high bandwidth dimension ratio (BDR). It is intended for use in microwave and millimeter-wave (mmWave) frequency applications. The designed antenna ensures low-dispersive behavior for both near- and far-field performance. The radiating element is composed of three circular rings that are interconnected by conical-shaped metal strips which lead to a fractal geometry. The design incorporates a partial ground plane and two parasitic patches located at the bottom and top sides of the substrate, respectively. The parasitic strips serve the purpose of enhancing impedance matching at lower frequency bands and reducing spurious radiation that may arise from the feed line. The proposed antenna has an overall size of 20×20 mm2 and exhibits an impedance bandwidth (IBW) of ≈57 GHz, spanning from 2.86 to beyond 60 GHz with a fractional bandwidth (FBW) of 181.8%, a ratio bandwidth (RBW) of 21:1, and a BDR of 5036. Furthermore, the peak gain value is observed to be ≈11 dBi, while the average gain within the operating range is ≈6 dBi. The proposed antenna design was also fabricated and tested, and experimental results show a reasonable agreement with the simulated data. This makes the antenna extremely suitable for energy harvesting applications in future fifth-generation (5G) and sixth-generation (6G) networks.
A new synthesis method of linear array antenna for wireless power transmission is introduced based on invasive weed algorithm in this paper. In order to improve the beam collection efficiency, the subarray division is carried out in the case of different azimuth angles and different numbers of array elements, respectively. Under the constraints of aperture size and minimum element spacing, the element positions, excitation coefficients and the element numbers of subarrays are optimized simultaneously. Compared with the optimization results obtained by other literature, it can be found that the proposed method in this paper can obtain a higher beam collection efficiency.
A compact selective ultra-wideband bandpass filter primarily based on a multi-mode resonator is presented in this paper. A modified elliptical split-ring resonator (SRR) embedded in a variant of the ring resonator is employed to configure a microstrip ultra-wideband (UWB) triple-notched bandpass filter with improved in-band and out-of-band filter properties. Further, the bent inter-digital coupled lines with aperture at the backside are applied to overall filter size miniaturization apart from contributing tight coupling through the entire structure. The three notches facilitated by the modified elliptic SRR have gained the ability to suppress the wireless local area network (WLAN) (5.48 GHz), C band RADAR (7.68 GHz), X band RADAR (8.82 GHz) interfering signals profoundly within the UWB. Simultaneously, the other filter attributes likely a uniform forward transmission coefficient with minimum attenuation (0.46 dB~1.52 dB), a high skirt factor (0.88), a wide passband (6.52 GHz) with high fractional bandwidth (FBW) (103.16%), broad upper stopband (3.47 GHz), etc. together establish the proposed filter, suitable for practical UWB applications. The uniqueness of this design lies in the flexibility to configure the filter as either a double-notched or a triple-notched bandpass filter by altering only the aspect ratios of elliptical SRR. Simulated filter characteristics are compared with the results obtained by measuring the fabricated prototype, and a good accordance between the compared outcomes validates the design pertinence well.
A novel synthesis method of a sparse rectangular planar receiving array (SRPRA) to maximize the power transmission efficiency (PTE) for microwave power transmission (MPT) is proposed in this paper. The array element positions of the SRPRA are symmetrically distributed among different quadrants such that the array elements at symmetrical positions receive the same power, and the SRPRA adopts a sparse layout. This reduces the number of array elements and simplifies the complexity of the feeding network. An improved adaptive chaotic particle swarm optimization (IACPSO) algorithm is proposed for the optimization synthesis problem of the SRPRA. Through the optimization of the proposed IACPSO algorithm, the optimal element layout of the SRPRA can be obtained efficiently to get the maximum PTE. In addition, we conduct a series of simulation experiments to verify the advantages of the proposed SRPRA model and the effectiveness of the IACPSO algorithm. Firstly, we analyze the effects of different parameters on the synthesis results of the SRPRA. Secondly, comparing the results with those of the sparse random circular aperture array (SRCAA), it is demonstrated that the SRPRA synthesized with the IACPSO algorithm can obtain higher PTE with fewer elements and has a relatively simple feeding network. Finally, compared with the standard particle swarm optimization (SPSO) algorithm, the proposed IACPSO algorithm can effectively and stably obtain the synthesis results of the SRPRA under different parameters. Therefore, the SRPRA is suitable for creating an efficient MPT system.
This paper presents the design, fabrication, and characterization of a novel single layer non- absorbing metasurface with a broadband epsilon near zero (ENZ) property and its application in-band gain enhancement of triple notch band ultra-wideband (UWB) antenna. The proposed metasurface is made up of non-resonant metamaterial unit cells consisting of half ring slots in a circular patch on an FR4 dielectric substrate. Metasurface with unit cells arranged in a 2×2 lattice pattern is suspended 4 mm above the triple notch band antenna. The transmission and reflection properties of the metamaterial unit cell are analysed and optimised to ensure the coherent transmission from the metasurface. The non-absorbing property of the metasurface results in the minimal loss of electromagnetic waves. The proposed antenna system with metasurface has a size of 28×28×7.2 mm3. The measured results of fabricated antenna are compared with the simulated ones and are in good match. The results show that the gain of the antenna was enhanced by 1.3 dB, 2.8 dB, and 4 dB at 5 GHz, 7 GHz, and 9 GHz, respectively.