Patch Resonator Research Articles

Multifunctional metasurface for Terahertz wavefront manipulation based on the combination of vanadium dioxide and graphene

In this paper, we propose a multifunctional wavefront control metasurface based on vanadium dioxide (VO2) and graphene. The unit cell structure contains a VO2 substrate, three rectangular metal strips as the bottom layer, orthogonal graphene strips as the top layer, and an intermediate layer consisting of a split ring resonator and circular metal patches. The desired performances can be achieved by changing the parameters of the split ring resonator in the middle layer, as well as controlling the phase transition state of VO2 and the Fermi level of graphene. When VO2 is in the insulating phase and the Fermi level of graphene is 1 eV, a transmissive metasurface is established, which realizes cross-polarization conversion, anomalous refraction, focusing lens, and orbital angular momentum generation at the frequency of 0.63 THz by changing the geometric sizes of the unit cell. When VO2 is in the metal phase and the Fermi level of graphene is 0.01 eV, a reflective metasurface can be achieved, which realizes terahertz beam splitting, radar cross section, and anomalous reflection of a single beam at the frequency of 0.63 THz. This multifunctional wavefront control metasurface treating the combination of VO2 and graphene exhibits significant application prospects in terahertz transmission, imaging, and communication.

THIẾT KẾ VẬT LIỆU BIẾN HOÁ PHÂN CỰC CHÉO BĂNG THÔNG RỘNG LÀM VIỆC TRONG VÙNG TẦN SỐ THz

A broadband and lightweight polarization converter is proposed for applications in the THz frequency region. The proposed design has a metasurface structure with the dielectric layer modified to a hollow structure to obtain a lightweight design. The unit cell consists of two opposite arcs resonator patches and a continuous metal patch separated by the polyimide substrate layer. The simulated results indicate that the proposed polarized converter achieves a polarization conversion ratio above 93% in the frequency range from 1.6 THz to 5.8 THz with a relative bandwidth of 113.5%.

Independently switchable dual-passband frequency-selective surface design based on characteristic mode analysis.

High-order bandpass filtering responses are highly desirable for frequency-selective surfaces (FSSs) in narrowband antenna/radar systems. In this paper, the design process of a reconfigurable dual-band FSS with second-order response is presented. Initially, the basic dumbbell-shaped resonator used in this design is theoretically investigated using the characteristic mode analysis (CMA) method to study the relation between geometric design parameters and the excited orthogonal resonance modes in different frequency bands. Then, an additional CMA process was performed on a unit cell with four such patch resonators arranged with 90-degree rotation between adjacent ones. This detailed analysis leads to a polarization-independent FSS design with a high-order dual-band response. Two of these composite resonators are combined back-to-back through coupling apertures on the middle layer. Finally, PIN diodes are loaded on separate layers to realize independent pass-band switching. The loading place of the PIN diodes is carefully chosen based on electromagnetic field analysis. A prototype was also fabricated and experimentally tested. Experimental results show that this FSS has two independently switchable passbands centered at 3 GHz and 4.8 GHz.

Compact wide‐stopband bandpass filter using FSIW‐patch triple‐mode resonator

AbstractIn this study, the compact third‐order filter with wide stopband is proposed, and it is based on the folded substrate integrated waveguide (FSIW)‐patch resonator. The embedded semicircular patch with two etched slots is integrated into the closed dual‐mode FSIW, so the miniaturized single‐cavity triple‐mode resonator with electromagnetic (EM) shielding and high quality can be achieved. In addition, the slots can reduce transverse electricity (TE)101 and TE201 on FSIW, while the other higher‐order modes of FSIW remain unchanged, then the wide stopband can be realized, and the stopband can be further widened by designing the feeding position to suppress higher‐order modes. Then, this filter based on hybrid FSIW modes has compact size, wide stopband, and good EM shielding. Finally, a prototype with 3‐dB fractional bandwidth of 8.4% is designed at 5.87 GHz (f0), and its insertion loss is only 1.16 dB. The upper‐stopband attenuation is better than 23 dB extended to 3.08f0. It occupies only 0.18λg2, where λg is the guided wavelength at f0.

A 1 × 2 Low-Profile Filtering Antenna Array Using Strip Dense Dielectric Patch.

A 1 × 2 low-profile filtering antenna array is proposed, using an H-shape resonator to feed two strip dense dielectric patch (DDP) resonators. The even-odd mode of the H-shape resonator and the TMδ1 mode of the strip DDP resonator form the radiation band. Additionally, the odd-odd mode of the H-shape resonator excites the TMδ2 mode of the strip DDP resonator, thus achieving an upper-edge radiation null for the filtering response. The H-shape resonator not only participates in the antenna array radiation, but also excites two strip media patches at the same time, avoiding the traditional power distribution network and effectively reducing the complexity of the antenna array. In addition, compared with the reported dielectric filtering antenna designs, this design has the advantageous features of a low profile, a compact structure, wide bandwidth and a simplified structure. For example, the antenna prototype operating at 4.9 GHz achieves 10 dB impedance, a matching bandwidth of 7.1%, a maximum gain of 8.6 dBi and the compact size of 1.29 × 0.18 × 0.038 λ03, without requiring a traditional power division network.

Graphene based filter design using triangular patch resonator for THz applications

In this paper, graphene based tunable bandpass and bandstop filters are designed in terahertz frequency regime using a triangular microstrip patch resonator. Initially, a bandpass filter is designed at an operating frequency of 1.65 THz with a bandwidth of 65 GHz. Further a dual-band bandstop filter is designed with resonance frequencies of 1.25 THz and 2.14 THz. In both designs, the triangular patch is coupled to the transmission line to achieve bandpass and bandstop characteristics. A graphene layer is deposited between the dielectric and the conductor layer to enhance the propagation of plasmonic waves. The simulation results reveal that the designed filters are capable of achieving the desired frequency response. By varying the graphene’s chemical potential, a shift in the transmission response’s resonance frequency is observed. The proposed filters have the potential to be used as key components for future terahertz band communications systems.

Miniaturised single‐layer bandpass filters using triple and quad‐mode patch resonators

AbstractThe authors propose miniaturised single‐layer bandpass filters (BPFs) by utilising a kind of new triple‐ and quad‐mode patch resonators. The triple‐mode resonator consists of a shortened square patch and a loaded metallic via at the centre. Characteristics of the new resonator are studied based on the mode analysis, and the first three resonant modes can be controlled well by changing the length of four via arms and the width of the open slot. Thus, a three‐pole BPF can be designed with the new triple‐mode patch resonator. To realise higher‐order filter, two triple‐mode patch resonators are cascaded to design a six‐pole BPF. Moreover, an inter‐digital slot‐line is further etched on the triple‐mode patch resonator to achieve a new resonant mode, and a quad‐mode patch resonator is achieved without increasing its size. A miniaturised four‐pole BPF is implemented using the quad‐mode patch resonator. For the demonstration, three‐pole triple‐mode, six‐pole triple‐mode and four‐pole quad‐mode patch filters are designed, fabricated and measured. The measured results are in good agreement with the simulated ones.

A single‐layered balanced filtering crossover with high selectivity based on square patch resonator

AbstractA new design of single‐layered balanced filtering crossover with high selectivity based on square patch resonator is proposed. Originated from the degenerate modes, that is, TM12 and TM21 on square patch resonators, the feasibility of intrinsic common‐mode (CM) suppression and channel isolation is conceived. For demonstration, a first‐order balanced crossover prototype is designed. Afterwards, to enhance selectivity, a square patch resonator is subtly divided into two identical parts and then introduced into the prototype. Hence, a balanced filtering crossover with a fifth‐order Chebyshev response is formed. Furthermore, stubs are deployed between adjacent patch resonators to introduce mixed couplings. Thus, two controllable transmission zeros are obtained, and better out‐of‐band suppression is achieved. Ultimately, the proposed crossover is fabricated and measured. High performance in terms of differential‐mode filtering response, in‐band CM suppression and channel isolation demonstrates the feasibility of the proposed method.

A Simple and General Method for Cross-Coupled Bandpass Filters Based on Circular Patch Resonator

In this article, a simple and general method for the design of cross-coupled bandpass filters with compact size is proposed by virtue of the circular patch resonator. Owing to the unique symmetry of the circle, such a circular patch resonator can be freely divided into several circular sector patch resonators along the radii. With this transformation, any two of the divided resonators have a possible coupling region. Specifically, the neighboring resonators have adjacent sides, while the vertices of all resonators are gathered in the center. Given this, the cross couplings can be easily constructed. Moreover, as the circular sector patch resonators with different boundary conditions along two sides have associated resonant properties, both positive and negative couplings can be provided. Consequently, the circular patch resonator should be a good candidate for the design of cross-coupled filters, and the concrete layout of the resultant filter can be determined by the design parameters as extracted from the design specifications. For demonstration, four design examples, including two single-band, one dual-band, and one tri-band bandpass filters, are constructed, fabricated, and measured. All measured results are in good accordance with the synthesized and simulated counterparts, thereby satisfactorily validating the feasibility and universality of the proposed design method.

Wideband single-feed dual circularly polarized multi-beam transmitarray antenna based on receiver–transmitter metasurface

In this paper, a novel metasurface (MS) as well as a generalized dual-circular-polarized (CP) decoupled modulating method are proposed. The proposed MS can realize high-efficiency dual-spin transmissions with equal-magnitude upon left handed circular polarization (LCP) incidence across 9–12.5 GHz. This MS is constructed based on the receiver–transmitter configuration, and the receiver layer composed of an LCP patch resonator while the transmitter layer is a linearly polarized patch resonator. Rotating the receiver and transmitter patches separately can impose identical and conjugated geometric phase modulations for the dual-CP transmission waves, respectively. Hence, through an elaborate combination of the dual geometric phases, totally decoupled and dispersion-less phase modulations for transmitted dual-spin waves can be obtained. As the proof of its uses in practical applications, we have designed a single-feed dual-CP dual-beam transmitarray antenna (TA) and a dual-CP quad-beam TA. The second TA is also fabricated and tested. The measured results are consistent with the simulated results, showing that the TA achieves peak aperture efficiency of 49% at 9.5 GHz, with 1 dB gain bandwidths (BWs) of the dual-CP quad-beams all larger than 24.5% while 3 dB axial ratio BWs all larger than 54.5%. The proposed wideband and high-gain dual-CP multi-beam TAs may have promising prospects for many applications such as vehicle-satellite communication systems, satellite broadcasting and coverage systems.

A Compact Circularly Polarized Crossed Dipole Antenna with Wide Bandwidth using Split Ring Resonator and Parasitic Patches

A new compact broadband circularly polarized (CP) crossed dipole antenna using split ring resonator (SRR) and parasitic patches are presented. The proposed antenna is mainly composed of two orthogonal strip dipoles, two 90∘ phase delay lines, four SRRs, and four parasitic patches. The combination of the orthogonal strip dipoles and the delay lines forms a crossed dipole as the main CP radiator. The well-designed SRR can extend the current path and improve the current distribution of high-frequency without increasing the size of the antenna, thereby reducing the size of the antenna and increasing the axial ratio (AR) bandwidth of the high-frequency. The introduction of parasitic patches can improve the current distribution between the upper and lower cut-off frequency points of the bandwidth, and make up for the defects of the insufficient bandwidth of the crossed dipole and the SRR, thereby realizing broadband CP radiation. To verify the antenna, a physical prototype is fabricated. The measured results show that the impedance bandwidth (IBW) of 69.1% (1.38-2.84 GHz), and a wide AR bandwidth of 57.7% (1.43-2.59 GHz). In addition, the designed antenna achieves a stable gain in the working band and a certain band-edge selectivity. Such a single-fed, simple structure and the wideband CP antenna is an excellent candidate for communication systems such as ISM (2.4 GHz), WiBro (2.3-2.39 GHz)and Inmarsat.

Design of Filtering Coupler Based on Patch Resonator with High Selectivity

In this paper, a new approach for designing a planar high frequency selectivity filtering coupler based on a circular patch resonator is proposed. In order to explain the operating principle, the resonant property of the circular patch resonator has been investigated firstly. Two circular patch resonators connected by two microstrip lines are used in this design. A filtering coupler is achieved by adjusting the feeder position and the length and width of the microstrip line used to connect the two resonators. Without additional circuits, the desired 0° and 180° phase differences are realized by the inherent in-phase and out-of-phase characteristics of E-fields at the TM11 mode. To improve the passband selectivity, transmission zeros are created by introducing a coupling between the source and load through the coupling slots etched on the ground. Finally, a prototype of the filtering coupler centered at 2.12 GHz is designed, implemented, and tested, while the measured results coincide well with simulated ones, verifying the proposed design concept.

Dielectric patch resonator and antenna

Dielectric patch resonator and antenna

Determination of a Measurement Procedure for the Study of Cells' Dielectric Properties through Descriptive Statistic.

This paper presents a measurement procedure for analyzing the dielectric properties of cells using descriptive statistics. The study focuses on four cancer cell lines (MDA-MB-231 and MCF-7 breast cancer, SaOS-2, and 143B osteosarcoma) and DMEM culture medium, utilizing the Lorentzian fit model of the return-loss function. The measurements are performed using a circular patch resonator with a 40 mm diameter, powered by a miniVNA operating in the frequency range of 1 MHz to 3 GHz. Eight specimens are prepared for each group to ensure reliability, and the return loss is recorded ten times for each specimen. Various statistical parameters are calculated and evaluated, including the average value, standard deviation, coefficient of variation, and relative error between the average and the first values. The results demonstrate that one single acquisition highly represents the entire set of ten data points, especially for the resonant frequency, with an accuracy error lower than 0.05%. These findings have significant implications for the methodological approach to detecting cells' dielectric properties, as they substantially reduce time and preserve the specimens without compromising the accuracy of the experimental results.

Highly‐selective microstrip bandpass filters based on new dual‐mode fan‐shape patch resonators

AbstractA design method for highly‐selective bandpass filters based on novel dual‐mode fan‐shaped patch resonator (FSPR) is presented in this article. Different from traditional dual‐mode patch filters, two higher‐order modes TM020 and TM110 are utilised to generate a passband, and the two resonant frequencies can be controlled well by its radius and angle. A dual‐mode filter with two transmission zeros (TZs) is implemented by using one FSPR, and locations of TZs can be controlled well. To further improve the selectivity of FSPR filters, four‐pole filters based on two identical dual‐mode FSPRs with co‐directional and reverse‐directional cascade are simulated, fabricated and measured. Furthermore, three‐ and four‐pole filters based on dual‐mode FSPR and single‐mode uniform impedance resonators are proposed, which are also simulated, fabricated, and measured. The later proposed filters not only achieve high selectivity and wide stopband, but also have simple structure and small size.

Compact wideband microstrip antennas using C, H, and W‐shape ground plane for GSM band applications

AbstractProximity‐fed compact wideband rectangular and circular microstrip antennas by employing H‐shape, C‐shape, and W‐shape ground plane profiles are proposed. Optimum results are obtained in rectangular microstrip antenna using H‐shape ground plane. Against the conventional ground plane, it gives 16% bandwidth improvement, supported by 17.29% and 31% reduction in resonant mode frequency and patch area, respectively. The proposed design exhibits a broadside pattern with a gain of 6.1 dBi and can find applications in GSM 900 band.

Design and Development of Ultrabroadband, High-Gain, and High-Isolation THz MIMO Antenna with a Complementary Split-Ring Resonator Metamaterial.

The need for high-speed communication has created a way to design THz antennas that operate at high frequencies, speeds, and data rates. In this manuscript, a THz MIMO antenna is designed using a metamaterial. The two-port antenna design proposed uses a complementary split-ring resonator patch. The design results are also compared with a simple patch antenna to show the improvement. The design shows a better isolation of 50 dB. A broadband width of 8.3 THz is achieved using this complementary split-ring resonator design. The percentage bandwidth is 90%, showing an ultrabroadband response. The highest gain of 10.34 dB is achieved with this design. Structural parametric optimization is applied to the complementary split-ring resonator MIMO antenna design. The designed antenna is also optimized by applying parametric optimization to different geometrical parameters. The optimized design has a 20 µm ground plane, 14 µm outer ring width, 6 µm inner ring width, and 1.6 µm substrate thickness. The proposed antenna with its broadband width, high gain, and high isolation could be applied in high-speed communication devices.

A Principal Componet Analysis to detect cancer cell line aggressiveness

In this paper, we propose the use of Principal Component Analysis (PCA) as a new post-processing method for the detection of breast and bone cancer cell lines cultured in vitro using a microwave biosensor. MDA-MB-231 and MCF7 breast cancer cell lines and SaOS-2 and 143B osteosarcoma cell lines were characterized using a circular patch resonator in the 1 MHz – 3 GHz frequency range. The return loss of each cancer cell line was analyzed, and the differences among each other were determined through Principal Component Analysis according to a protocol previously proposed mainly for electrocardiogram processing and X-ray photoelectron spectroscopy. Our results showed that the four cancer cell lines analyzed exhibited peculiar dielectric properties when compared to each other and the growth medium, confirming that PCA could be employed as an alternative methodology to analyze microwave characterization of cancer cell lines which, in turn, may be deeply exploited as a tool for the detection of cancer cells in healthy tissues.

Design and analysis of split ring resonator engraved metamaterial broadband and high gain patch antenna for THz applications

We propose a new split ring resonator engraved metamaterial MIMO patch antenna design which applies in 6–11 THz frequency band. Four different THz antennas are investigated and their results are compared to find the optimized antenna design with superstrate. The four antenna designs evolved by adding superstrate layers and metamaterials in the form of complementary split ring resonators are investigated. They are THz patch antenna (TPA), THz complementary split ring resonator patch antenna (TCPA), THz patch antenna with complementary split ring resonator superstrate (TPACS), and THz complementary split ring resonator patch antenna with complementary split ring resonator superstrate (TCPACS). The results show that the complementary split ring resonator metamaterial added in the patch as well as in the superstrate affects the antenna gain and bandwidth while the addition of the superstrate affects the multiband and gain characteristics. All four designs are optimized and show the multiband response. The TCPACS design exhibits the highest bandwidth of 900 GHz 8.88%) and the highest gain of 9.19 dB. The TCPA design is having highest bandwidth of 530 GHz (5.3%) and the highest gain of 8.05 dB. The TPACS design is having highest bandwidth of 300 GHz (3%) and the highest gain of 7.47 dB. The TPA design is having highest bandwidth of 60 GHz (0.6%) and the highest gain of 6.42 dB. The proposed antenna design with multiband, broadband, high-gain and optically transparent characteristics can be used in Terahertz Wireless Area Networks, Terahertz Wi-Fi, 6 G, Internet of Things, Sensing and Imaging applications. Availability of data and materialsThe data supporting the findings in this work are available from the corresponding author with a reasonable request.

A Wideband Differential-Fed Microstrip Patch Antenna Based on Quad-Mode Resonance With Radiation Patterns Correction

A wideband differential-fed microstrip patch antenna (DMPA) based on quad-mode resonance with radiation patterns correction is proposed in this paper. First, the common problems presented in multi-mode resonant microstrip patch antenna (MPA) are introduced: it is difficult for the numbers of operation modes to exceed two, and there are radiation nulls emerged in the broadside. Second, the physical structure and mode combination process of the DMPA are demonstrated in detail. Third, through the equivalent magnetic current array model, we comprehensively introduce the principles and processes of radiation patterns correction. Finally, a prototype is fabricated and measured. The measuring results are consisted with simulation ones. The proposed DMPA achieves 29.4% (3.22 GHz – 4.33 GHz) impedance bandwidth at the profile of 0.058λ (center frequency wavelength), and it has a stable gain in broadside without radiation nulls.