Zeroth-order Resonant Antenna Research Articles

Design and bandwidth enhancement of zeroth-order resonator antenna using metamaterial

In this paper, a compact configuration of zeroth-order resonator antenna is described. The unit cell zeroth-order resonator properties are introduced by composite right/left-handed transmission line approach is fed by coplanar waveguide. The proposed resonator is analyzed by changing the coupling space and stub length of the unit cell. The size of implemented resonator is (0.185 λ 0 × 0.185 λ 0 × 0.027 λ 0 ) at the centre frequency. In this work, a zeroth-order resonator antenna design with enhanced bandwidth has been presented, and the size reduction by using the metamaterial inclusion. The proposed zeroth-order resonant antenna (ZORA) achieves a 64% reduction compared to a traditional λ/2 microstrip patch antenna. The bandwidth for the 10 dB return loss is 5.66 GHz (2.76 GHz to 8.42 GHz), the peak value of gain is 0.8 dBi and radiation efficiency of the designed antenna is 87% at 5.5 GHz. The return loss is about -59.48 dB at the center frequency. The competition among the simulated performances and other antennas shows that the proposed resonator achieves wide bandwidth. The performance of zeroth-order resonator antenna is evaluated by full-wave electromagnetic (EM) simulator HFSS11

A High-Efficiency Zeroth-Order Resonant (ZOR) Antenna Fed by Printed Ridge-Gap Waveguide Technology

In this paper, a zeroth-order resonator (ZOR) antenna fed by a printed ridge gap waveguide (PRGW) is reported for 5G/6G applications in millimeter-wave bands. A zeroth-order resonance (ZOR) order technique with omnidirectional pattern feature is incorporated into a slot antenna to increase the coverage area of the slot antenna with high gain and directive pattern. The proposed antenna supports a high radiation efficiency and stable high coverage directional gain characteristic.

A novel compact folded zeroth-order resonant antenna for Internet of Things USB dongle applications

ABSTRACT This article presents a novel compact folded Zeroth-Order Resonant (ZOR) antenna using concept of Composite Right/Left-Handed (CRLH) transmission line operating in the WLAN/ISM bands of 2.4 and 5.2 GHz for Internet of Things (IoT) applications including USB dongle and radio-frequency identification (RFID) systems. It consists of two-unit cells of a CRLH transmission line and operates in a series resonant mode with an overall size of 1.6 mm × 38 mm × 9 mm. The measured results show that fractional bandwidths of 11.34% and 3.9% for S11 < −10 dB, and radiation efficiencies of 64.89% at 2.4 GHz and 78.88% at 5.2 GHz are obtained. A comparison between our proposed work and other existing works shows the achievement of considerable antenna miniaturization using the technique of CLRH transmission line. The measured and simulated results are generally in good consensus. Being novel and compact, the proposed design is a potential candidate for diverse IoT devices including USB dongles and low-profile RFID tags.

Compact Wideband Dual-Frequency Antenna Based on a Simplified Composite Right/Left-Handed Transmission Line with Hilbert Curve Loading

This paper addresses the issues of low bandwidth, gain, and efficiency of miniaturized microwave antennas by proposing a novel wideband dual-frequency coplanar waveguide antenna design based on a simplified composite right/left-handed (SCRLH) transmission line structure with Hilbert curve loading. The multifrequency characteristics of the SCRLH transmission line structure are evaluated theoretically, and the antenna parameters promoting bandwidth broadening under zeroth-order resonance (ZOR) and first-order resonance (FOR) mode operation are evaluated. The bandwidth broadening in the ZOR and FOR modes is accordingly revealed to be independent of the antenna length, and the structure therefore facilitates wideband operation under miniaturization. Finally, the dual-frequency ZOR and FOR mode antenna design with center frequencies of f0 = 1.865 GHz and f1 = 2.835 GHz is validated via simulation, and the performance of a compact prototype antenna is evaluated experimentally. The −10 dB return loss bandwidths at f0 and f1 are 187 MHz (from 1.773 GHz to 1.96 GHz) and 368 MHz (from 3.002 GHz to 3.37 GHz), and the corresponding relative bandwidths are 10.1% and 11.5%, respectively. The experimentally measured peak gains and radiation efficiencies at f0 are 1.54 dB and 81.3%, respectively, and those at f1 are 1.71 dB and 74.2%, respectively.

Circularly polarized ACPW Fed CRLH-TL based ZOR antenna with band notch characteristics

AbstractIn this paper, two asymmetric co-planar waveguide (ACPW) fed circularly polarized (CP) zeroth-order resonance (ZOR) antennas (Antenna I and II) are presented using a composite right and left-handed transmission line (CRLH-TL) approach. By adding a stub on the left side of the ACPW ground and adjusting its length, circularly polarization property has been achieved in Antenna I. The simulated 3 dB axial ratio bandwidth (ARBW) of Antenna I is 1750 MHz (3.50–5.25 GHz). Next, the left side ground plane of Antenna I is further defected by etching a quarter wavelength slit to introduce a notch band (Antenna II). Antenna II has an extended 10 dB return loss bandwidth of 2200 MHz (3.28–5.48 GHz) with a band notch from 4.18–4.65 GHz that isolates the WiMAX and 5.2 GHz WLAN bands. ARBWs of 1080 and 870 MHz are achieved in the first and second band of Antenna II. The overlapping 3 dB ARBW and 10 dB return loss bandwidths of Antenna II in these two bands are 770 and 830 MHz, respectively.

A CPW‐fed band notched wideband circularly polarized ZOR antenna based on CRLH‐TL approach

This article presents design and analysis of three wide band zeroth-order resonance antennas (antennas I, II, and III) using composite right and left-handed transmission line (CRLH-TL) approach. Coplanar waveguide technology, single layer via-less structures are used to have the design flexibility. The bandwidth characteristics are analyzed by using lumped parameters of CRLH-TL. By introducing a simple slot in the ground plane of antenna I both bandwidth enhancement and circularly polarization characteristics are achieved in antenna II. Another quarter wave L-shaped slot has been introduced in the ground plane of antenna II to introduce a notch band in the frequency response of antenna III. Achieved measured 10 dB return loss bandwidth of antenna I and antenna II are 960 (3.3-4.26 GHz) and 2890 MHz (2.77-5.66 GHz), respectively. Antenna III offers measured 10 dB return loss bandwidth of 3220 MHz (2.32-5.54 GHz) with a band notch from 2.39 to 2.99 GHz that isolates the 2.4 GHz WLAN and 3.5 GHz WiMAX band. Antenna II and antenna III have circular polarization property with measured axial ratio bandwidth of 440 MHz. The measured peak realized gain of antennas II and III is around 1.53-2.9 dBi.

A Metamaterial Inspired ZOR Antenna Using IDC and Spiral Inductor with Partial Ground Plane for WLAN Application

In this article, an open-ended metamaterial antenna structure is designed for WLAN application. The antenna comprises of an interdigital capacitor (IDC) and spiral inductor with a partial ground plane. The IDC (shunt element) act as a varying parameter to control the zeroth-order resonance (ZOR) frequency, whereas spiral inductor (series element) is used to form a first negative order resonance frequency at 2.29 GHz. The ZOR mode has been excited at 4.53 GHz by employing complimentary right/left handed transmission line model in the structure and the first positive order resonance (FPOR) frequency is obtained at 4.9 GHz. A rectangular shaped stub has been used to act as a virtual ground for IDC. The proposed antenna design has total foot-print size of 0.29λ0 × 0.27λ0 × 0.024λ0. The fractional bandwidth of 20.41% (4.36–5.35 GHz) is achieved due to the merging of ZOR and FPOR mode respectively. In addition, it also exhibits a measured peak gain of 2.12 dB and 2 dB with a radiation efficiency of 77.76% and 87.62% at ZOR and FPOR frequencies respectively. A prototype of the proposed antenna structure has been fabricated and simulation results are experimentally rectified. A good agreement between simulation and measured results are obtained.

Co-axial fed triple-band and dual-band zeroth order antennas using pseudo-open termination unit cells for C-band applications

In this paper, a triple-band and dual-band zeroth order resonance (ZOR) epsilon negative antennas are proposed using two pseudo-open termination unit cells for the case where the shunt ZOR (fsh) is higher than the series ZOR (fse1). The epsilon negative transmission line (ENG TL) resonates fsh while the series ZORs (fse1 and fse2) are excited by the series capacitance of the two pseudo-open termination unit cells. If the series capacitances of the two pseudo-open termination unit cells are different then fse1 and fse2 are excited, else only fse1 is excited. fse1 and fse2 along with fsh results in triple-band ZOR antenna, while a single fse1 with fsh results in dual-band ZOR antenna. The pseudo-open termination unit cells can be placed anywhere around the ENG TL to get proper matching. All the resonances for both the antennas follow zeroth order characteristics which are verified using electric field vector. The measured peak gains of the triple-band ZOR antenna for fse2,fse1 and fsh are 1.14 dBi, 1.39 dBi, and 2.19 dBi, respectively, with dipole mode for fsh. For dual-band ZOR antenna, the measured peak gains for fse1 is 1.4 dBi, and fsh is 2.05 dBi, with dipole mode for fse1 and fsh.

Detection and Imaging of Magnetic Field in the Microwave Regime With a Combination of Magnetic Losses Material and Thermofluorescent Molecules

Characterization of the electromagnetic field emitted by various sources (antenna, radar, etc.) is an important issue, either for civil or defense applications. The measurement of electromagnetic field may be performed either by local probes or by thermography imaging, in particular with an infrared camera. The latter method, called electromagnetic infrared (EMIR) has been developed several years ago. We have recently successfully implemented this technique in the domain of visible light thanks to the combination of a film sensitive to either electric field (slightly conductive film) or magnetic field (insulating film with ferromagnetic particles) and a polymer coating doped with fluorescent molecules with an emission depending on temperature, indeed a thermofluorescent sensor. We present our recent results obtained imaging the microwave magnetic field emitted in the near field of a zeroth-order resonator (ZOR) antenna. The sensing film is a stack of FLEX-TOKIN magnetic absorber, already tested by EMIR infrared thermography in our group. A 20 µm film composed of a mixture of rhodamine B (RhB) in an epoxy matrix is screen printed on the FLEX surface. RhB, in ethanol solution, has a thermofluorescence coefficient of ∼2%/K at room temperature at its maximum of fluorescence of 595 nm. Excitation light is delivered by an array of blue 470 nm LEDs. The 4.29 GHz microwave excitation of the ZOR device is amplitude modulated at 0.1-0.5 Hz in order to cancel any thermal drift and convection of the thermofluorescence image. Low-frequency excitation modulation also allows noise cancellation via image pixel demodulation postprocessing. We present the deduced temperature mapping of the sensing film placed 2 mm above the ZOR patch antenna.

Compact zeroth-order resonator (ZOR) antennas

In this paper, we introduce and review the zeroth-order resonator (ZOR) antennas with outstanding characteristics including various applications that have been researched so far. Since the zeroth-order resonance frequency is independent of a physical length of antenna, the ZOR antenna can theoretically be designed quite small and have a possibility to apply to considerably lots of applications. First, we have presented the ZOR antennas implemented by double-negative (DNG), epsilon-negative (ENG), and mu-negative (MNG) transmission lines. Then, the research related on extremely small, wide beamwidth, wideband, and circularly polarized (CP) ZOR antennas have been continuously carried out. Based on a series of these studies, the ZOR antennas were utilized for various applications such as a wireless power transfer (WPT), a compact controlled reception pattern antenna (CRPA), a penta-band mobile antenna, and a wide steering array antenna.

Design of Zeroth-order resonance antenna array with a pair of DPS and ENG materials

This paper proposes one-dimensional antenna arrays of the four-element and the eight-element using composite materials. Firstly, the single element is designed to resonate at Zeroth-order using a pair of Double positive (DPS) and Epsilon negative (ENG) materials meta-structured transmission line (MTL). Secondly, three of 1:2 T-Junction power dividers and seven of 1:2 T-Junction power dividers based on micro-strip technology are designed for feeding the four-element and the eight-element array antennas, respectively. Finally, the proposed arrays are optimized using FEM-based simulation to operate at the frequency of 8,5 GHz. The simulated results show that both antenna arrays have Zeroth-order resonance (ZOR) property, in which the four-element array has a bandwidth spreading from 8.39 to 8.61 GHz and a maximum gain of 8.82 dB while the other one of the eight-element array is 8.39 – 8.60 GHz and 12.2 dB, respectively. The proposed array antennas can be used for wireless applications or mobile communications.

Millimeter-wave beam-steering high gain array antenna by utilizing metamaterial zeroth-order resonance elements and Fabry-Perot technique

Millimeter-wave (mm-wave) beam-steering antennas are preferred for reducing the disruptive effects, such as those caused by high atmospheric debilitation in wireless communications systems. In this work, a compact broadband antenna array with a low loss feed network design is introduced. To overcome the short-range effects on mm-wave frequencies, a feed network – with a modified Butler matrix and a compact zeroth-order resonance antenna element – has been designed. Furthermore, the aperture feed technique has been utilized to provide a broadside stable pattern and improve the delivered gain. A Fabry-Perot layer without the height of the air layer is used. Taking advantage of this novel design, a broadband and compact beam-steering array antenna – capable of covering impedance bandwidths (from 33.84 to 36.59 GHz) and scanning a solid angle of about ~94°, with a peak gain of 17.6 dBi – is attained.

A novel ACPW-fed quad-band hybrid antenna for wireless applications

This paper presents a novel asymmetric coplanar waveguide-fed quad-band hybrid antenna for wireless applications. The proposed hybrid antenna combines a conventional monopole antenna and a zeroth-order resonator antenna to perform a dual-mode operation. The first mode is generated by a slotted monopole antenna, supporting the two higher resonances at about 3.5 and 5.8 GHz. The second mode is supported by loading a composite right-/left-handed transmission line unit cell near the slotted monopole, contributing to the two lower resonances at about 1.6 and 2.5 GHz. It is printed on an FR4 substrate with the overall dimensions of 40 mm × 24 mm × 1.6 mm. Experimental results demonstrate that it can cover the global positioning system (1.57–1.59 GHz), wireless local area network (2.4–2.485, 5.15–5.35, and 5.725–5.825 GHz), and worldwide interoperability for microwave access (2.5–2.69, 3.3–3.7, and 5.25–5.85 GHz) applications with monopole-like radiation patterns and acceptable gains.

Bandwidth enhancement of ZOR antenna by loading novel via-Less CRLH-TL unit cells

Novel via-less CRLH-TL unit cells loaded compact and bandwidth-enhanced zeroth-order resonant (ZOR) antennas have been designed and experimentally verified. Two CRLH-TL unit cells are designed and loaded in monopole antennas to enhance the bandwidth. The series capacitance of CRLH-TL unit cell is implemented with both interdigital capacitance/gap capacitance and shunt inductance is implemented with meander line inductance. The dispersion characteristics of the proposed unit cells are numerically calculated which follows CRLH-TL properties. Further, the conventional CRLH-TL unit cell metallic vias have been eliminated by using two novel techniques, which increases the fabrication flexibility. The compactness has been achieved by realizing ZOR mode and the resulting four open-ended ZOR antenna’s bandwidth is increased by realizing small shunt capacitance and large shunt inductance. Further, to increase its bandwidth, merging of ZOR mode to the higher and lower order modes into a single passband by realizing proper CRLH-TL unit cells has been done. The each proposed antenna has a compact dimension of 25 × 15 × 1.6 mm3 and S11 < −10 dB impedance bandwidths of 9.6 GHz, 9.7 GHz, 10 GHz and 9.6 GHz respectively. The optimum gain, good efficiency and desired radiation characteristics have been achieved for proposed antennas, which are most suitable for ultra-wideband applications. The CST-MWS has been used for the parametric study of the proposed antennas. A good agreement has been achieved between simulated and measured results.

Semitransparent and Flexible Mechanically Reconfigurable Electrically Small Antennas Based on Tortuous Metallic Micromesh

A novel optically transparent, flexible, and mechanically reconfigurable zeroth-order resonant (ZOR) antenna using stretchable micromesh structure is presented in this paper. The size reduction of the antenna is achieved by using the ZOR property, and the uniform metallic patches of the antenna are replaced with the tortuous micromesh. The tortuous micromesh structures provide a high degree of freedom for stretching when encapsulated in elastomeric polymers with added feature of semitransparency. Accordingly, the structure can undergo mechanical deformation such as stretching (up to 40%), folding, or twisting without breakage. The resonant frequency of the antennas is linearly reconfigurable from 2.94 to 2.46 GHz upon stretching.

Compact Broadband Dual ZOR Antenna for Multiband Smart Mobile Phone Applications

A compact broadband dual zeroth-order resonator (ZOR) antenna is proposed for multiband smart mobile phone applications. The theory of broadband zeroth-order mode and multimode technique is used to design the proposed antenna covering GSM850 (824–894 MHz), GSM900 (880–960 MHz), DCS1800 (1710–1880 MHz), PCS1900 (1850–1990 MHz), W2100 (1920–2170 MHz), LTE2300 (2300–2400 MHz), LTE2600 (2500–2690 MHz), and Wi-Fi (2400–2500 MHz) bands. In order to achieve broadband operations, the proposed antenna consists of a large ZOR and a small ZOR that can generate and merge resonant frequencies of the negative-order, zeroth-order, and positive-order modes. The overall size of the antenna is 40 mm × 6 mm × 3 mm. The performance of the antenna is verified by both full-wave simulations and experiments. The measured impedance bandwidths of 3 : 1 VSWR in the low and high bands are 210 MHz (0.81–1.02 GHz) and 1170 MHz (1.69–2.86 GHz), respectively. The antenna provides omnidirectional radiation patterns and measured radiation efficiencies exceeding 43.3% and 47.5% for low and high bands, respectively. The antenna performance applied to the commercial smart mobile phone device is also presented. The measured results show that it has the active performance of good total radiated power, total isotropic sensitivity, and specific absorption rate, which can meet the requirement of the smart mobile phone.

Design and Analysis of a New ZOR Antenna with Wide Half Power Beam Width (HPBW) Characteristic

Abstract Novel zeroth-order resonator (ZOR) composites epsilon-zero resonance (EZR) and mu-zero resonance (MZR) characteristics was proposed. The proposed resonator was constructed by moving via from centre of the conventional mushroom structure (CMS) to the edge, then, an edge-located via mushroom structure (ELV-MS) was formed. Thus, boundary conditions were transformed from all open-ended to half short-ended and half open-ended. Then, the new ZOR composites EZR and MZR characteristics (called EZR-MZR resonator). Owing to the unique characteristic of the composite EZR and MZR, the proposed ZOR antenna radiates both horizontal-polarized field (uni-directional) and vertical-polarized field (omni-directional). Then, wide half power beam width (HPBW) radiation patterns were realized for the antenna. The deduction and analysis of the proposed EZR-MZR resonator were conducted based on the composite right/left-handed transmission line (CRLH TL) and ZOR theories, and field distributions. The proposed ZOR antenna was investigated with two cases of coupling feeding.

Low‐profile antenna for millimetre‐wave chip‐to‐chip communication

Here, the authors report a low-profile antenna for millimetre-wave chip-to-chip communication. The height of the proposed antenna is limited to 0.18 mm, 1/20 wavelength at 80 GHz. To realise such a low profile, a zeroth-order resonator antenna with a periodic array of four unit cells was employed, and its geometry was optimised using a full-wave simulation tool to cover an 8 GHz bandwidth from 76 to 84 GHz. With this, the antenna was capable of radiating in the end-fire direction parallel to the board length despite the short distance between the ground and the radiator. Simulation and measurement results showed that the optimised design had low reflection coefficients and consistent radiation patterns throughout the target bandwidth.

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Compact Penta-Band Dual ZOR Antenna for Mobile Applications

A compact penta-band dual zeroth order resonator (ZOR) antenna with band-stop filter is proposed for mobile applications. The ZOR antenna is designed with modified mushroom-like structures extended on nonground region to obtain good efficiency and broad bandwidth. This modified mushroom-like structure is confirmed as double negative (DNG) transmission line by full wave simulated dispersion relation. Moreover, a bended patch and a band-stop filter (BSF) are employed to increase efficiency and bandwidth, respectively. The length of each antenna is aboutλ0/10at the resonant frequencies of 900 MHz and 1800 MHz, respectively. The overall dimension of the antenna is 54.4 mm (length) × 4 mm (width) × 5 mm (height). The total efficiencies in low and high bands are measured more than 40% and 70%, respectively.