Bandwidth enhancement of dual-band bi-directional microstrip antenna using complementary split ring resonator with defected structure for 3/5 GHz applications

<span>This paper presents a bandwidth enhancement of a dual-band bi-directional rectangular microstrip patch antenna. The novelty of this work lies in the modification of conventional rectangular microstip patch antenna by using the combination of two techniques: a complementary split ring resonator (CSRR) and a defected patch structure (DPS). The structure of antenna was studied and investigated via computer </span><span>simulation technology (CST). The dimension and position of CSRR on the ground plane was optimized to achieve dual bandwidth and bi-directional radiation pattern characteristics. In addition, the bandwidths were enhanced by defecting suitable shape incorporated in the microstrip patch. A prototype with overall dimension of 70.45×63.73 mm² has been fabricated on FR-4 substrate. To verify the proposed design, the impedance bandwidth, gain, and radiation patterns were carried out in measurements. The measured impedance bandwidths were respectively 560 MHz (3.08-3.64 GHz) and 950 GHz (4.64-5.59 GHz) while the measured gains of each bandwidth were respectively 4.28 dBi and 4.63 dBi. The measured radiation patterns were in good agreement with simulated ones. The proposed antenna achieves wide dual bandwidth and bi-directional radiation patterns performances. Consequently, it is a promising candidate for Wi-Fi or 5G communications in specific areas such as tunnel, corridor, or transit and rail.</span>

Demonstration of Dipole-Induced Transparency Using Mirrored Split-Ring Resonator Metasurface For Microwave Applications

In this paper, dipole-induced transparency in the microwave regime is proposed and verified using experimental and simulation studies. A single layer mirrored Split-Ring Resonator (SRR) metasurface array working under the H⊥excitation scenario is used to achieveout-of-phase electric dipole moments on the metasurface for a normal incident plane wave. The emergence of the transparency window is accompanied by the destructive interference between out-of-phase oscillating electric dipole moments on the metasurfaceand is verified in computations by studying the radar Cross Section in full-wave electromagnetic simulations.We used the multipole scattering theory to validate the results computationally. The coupling effects are studied numerically, and the emergence of the transparency window is studied experimentally using transmission measurements inside an anechoic chamber using a vector network analyzer.

Circular Complementary Split Ring Resonator Rotation for Linear Array Millimeter Wave Microstrip Patch Antenna

This paper proposes multiple linear array millimeter wave MPAs that could operate at various frequencies depending on the angular rotation of the CSRR structure. The main contribution of this work is the range of frequencies of the linear array MPA found when the position of the CSRR structure is changed angularly. This is achieved by positioning the CSRR structure on the ground plane of the MPA and rotate it to an incremental of 22.5°. Computer Simulation Technology software is used to simulate the antenna designs. The performance of the antenna is evaluated against the single element millimeter wave MPA with similar angular rotation to the CSRR structure. The reflection coefficient graph shows at 0° rotation, the antenna has dual band performance at 26 GHz and 28 GHz. At 22.5° and 45° CSRR structure rotation, the antenna shows triple band performance with different operational frequencies and different polarization depending on the frequencies. Finally, at 67.5° CSRR structure rotation, the antenna now is operational only at 20 GHz frequency with horizontal polarization performance. Plus, the results between the single element MPA with circular CSSRR and the linear array MPA with circular CSRR shows similar behavior in which the rotation of the CSRR did not affect the antenna differently even with an increase of the number of elements. The millimeter wave MPA with CSRR angular rotation can be utilized in various applications as it covers multiple frequencies depending on the angle of rotation of the CSRR structure.

A Miniaturized CSRR Loaded 2-Element MIMO Antenna for LTE Band

A miniaturized 2 x 1 multiple-input multiple-output (MIMO) antenna is presented in this paper. The designed antenna contains two circular patches with Complimentary Split-Ring Resonator (CSRR) that are etched in the ground which has a profound effect on antenna size reduction. It also helps in the reduction of isolation between two antennas. The maximum isolation between the two antennas is -84.62 dB at 2.8 GHz. The size of an antenna becomes more compact i.e., 40 x 20 x 1.6 mm3 after incorporating CSRR. The maximum gain of the designed antenna is 5.8 dBi at 4.3 GHz and the minimum reflection coefficient is -35.15 dB at 1.63 GHz. The operating band of an antenna is wide from 1.3 GHz to 4.3 GHz which covers Bluetooth, WiMax, and LTE applications. The proposed antenna is useful for various wireless applications.

Design and Implementation of a Multiband Metamaterial-Loaded Reconfigurable Antenna for Wireless Applications

This article presents a multiband antenna with the implementation of a metamaterial split-ring resonator (SRR), quasicomplementary split-ring resonator (CSRR), and slots to achieve octaband characteristics for wireless standards. Multiband features are accomplished by the implementation of the slot approach within the radiating section part and loading the SRR and CSRR cells. The electrical dimension is 0.256λ × 0.176 λ × 0.0128λ (32 × 22 × 1.6 mm3) of the proposed design, at a lower frequency of 2.4 GHz. The proposed design indicates the frequency-band reconfigurability nature by using the switching PIN diode placed at the slotted section of the ground plane. During the OFF state of switching, the element structure resonates in eight wireless communication bands covering various high-speed multiple applications of Internet of Things (IoT) regarding wireless standards S-band WLAN (WiFi, Bluetooth, Z-wave, wireless HART, and WBAN), lower C-band (WAIC, satellite communication transmission application), C-band WLAN, X-band (ITU region 2), Ku-band (direct broadcast satellite system and terrestrial microwave communication system service), and K-band (radar communication application) at 2.4, 4.3, 5.8, 8.5, 11.1, 13.9, 16.1, and 18.9 GHz, respectively, with S11 ≤ −10 dB. The antenna achieves an optimum peak gain of 4.23 dBi and radiation efficiency of 82.78% at operating frequency regarding wireless standards. The average efficiency of the proposed design is more than 70% for all resonant modes. The radiation characteristics (gain/efficiency/patterns/impedance matching) are shown in the stable and improved form at achieved wireless modes.

Characteristics of Left Handed Materials

Researchers have been interested in studying so-called Left-Handed Metamaterials LHM, which are artificial materials. These materials have unusual characteristics, like negative permittivity and permeability, and therefore negative index. This paper has been discussed some characteristics of LHM by designing a square split ring resonator SRR and simulating with CST microwave studio (Computer Simulation Technology) to get S-parameters. The broadband frequencies (0-30) GHz were taking to specify the effective range of frequencies to work with, which was found to be between (8- 14) GHz. Then, the parameters of SRR have been varied such as split width on, gap width, metal width, rod width and metal material. The measurements show some of parameters have been affected the values of resonance frequency and the others are not. Also, the negative values of permittivity, permeability, and refractive index have been approved.

A 4 × 4 Array of Complementary Split-Ring Resonators for Label-Free Dielectric Spectroscopy

In this study, complementary split-ring resonator (CSRR) metamaterial structures are proposed for label-free dielectric spectroscopy of liquids in microplates. This novel combination of an array of sensors and microplates is readily scalable and thus offers a great potential for non-invasive, rapid, and label-free dielectric spectroscopy of liquids in large microplate arrays. The proposed array of sensors on a printed circuit board consists of a microstrip line coupled to four CSRRs in cascade with resonant frequencies ranging from 7 to 10 GHz, spaced around 1 GHz. The microwells were manufactured and bonded to the CSRR using polydimethylsiloxane, whose resonant frequency is dependent on a complex relative permittivity of the liquid loaded in the microwell. The individual microstrip lines with CSRRs were interconnected to the measurement equipment using two electronically controllable microwave switches, which enables microwave measurements of the 4 × 4 CSRR array using only a two-port measurement system. The 4 × 4 microwell sensor arrays were calibrated and evaluated using water-ethanol mixtures with different ethanol concentrations. The proposed measurement setup offers comparable results to ones obtained using a dielectric probe, confirming the potential of the planar sensor array for large-scale microplate experiments.

Dual-band ambient energy harvesting systems based on metamaterials for self-powered indoorwireless sensor nodes

In this study, we present a comprehensive dual-band ambient radio-frequency (RF) energy harvesting system, consisting of rectenna and power management circuit, to harvest energy from 2.45 and 5.8 GHz Wi-Fi. The rectenna employs a metamaterial antenna based on a split-ring resonator, which possesses omni-directional radiation pattern at both frequencies and compact size (0.18λ × 0.25λ at 2.45 GHz). The dual-band rectifier yields the highest efficiency of 42% at 2.45 GHz and 1 dBm input power, 30% at 5.8 GHz and − 7 dBm input power. The maximum RF-DC efficiency for each band is 72% at − 5 dBm and 27% at − 2 dBm, respectively. The power management circuit, consisting of a storing capacitor and a boost converter, is integrated to produce a stable, sufficient output voltage. The energy harvesting system, with its comprehensiveness, is suitable for supplying low-power wireless sensor nodes for indoor applications.