Multi-resonant Antenna Research Articles

Multi resonant slot antenna design to radiate fan‐shaped multi‐beam radiation pattern with the use of two‐dimensional perforated Luneburg lens

Multi resonant slot antenna design to radiate fan‐shaped multi‐beam radiation pattern with the use of two‐dimensional perforated Luneburg lens

Substrate Integrated Waveguide - Dielectric Resonator Antenna for Future Wireless Communication

A substrate integrated waveguide (SIW) fed rectangular-shaped dielectric resonator antenna (DRA) is proposed for application in the D - Band frequency regime. The Dielectric Resonator (DR) is designed to operate in higher order modes. A rectangular-shaped narrow slot is used to excite the DR element, leading to multiple resonances. The resulting structure is a multi-resonant antenna operating at six frequencies at 123.64 GHz, 125.76 GHz, 127.4 GHz, 129.9 GHz, 134.9 GHz and 137.7 GHz frequencies. These are identified as TE10δ1, TE7δ5, TEδ31, TEδ25, TEδ31 and TEδ35 modes of operation of the resonator, respectively. These resonances are merged to achieve a −10 dB impedance bandwidth ranging between 122.58 GHz and 139.51 GHz, equivalent to 13.4% at a center frequency of 125.76 GHz. Moreover, the antenna possesses a stable radiation pattern in the broadband direction, across the entire frequency band of operation. Simulation results show that the antenna has a peak gain of 12.3 dBi, maximum directivity of 13.14 dBi and maximum efficiency of 84% at a frequency of 126 GHz. Simulated results show that the proposed design has potential and suitability for utilization in future wireless communications.

The Impact of Group Delay Dispersion on Radar Imaging With Multiresonant Antennas

Radar sensing has become very popular over the last two decades, and research has focused on high-bandwidth and high-resolution systems. Due to the steadily increasing center frequency of front-end circuits, on-chip antennas are the preferred choice over PCB antennas and horn antennas when frequencies get close to THz. However, conventional on-chip antennas are severely limited in bandwidth, leading to increased use of wideband and multiresonant on-chip antennas. Besides a more complex design process of multiresonant antennas, they have the disadvantage of a nonconstant dispersive group delay (GD). This reduces the resolution of sensing systems, such as the range resolution and angular resolution of a radar system. In this work, we show how GD affects the imaging properties of a radar system. The measured S-parameter data from a 240-GHz multiresonant antenna are used to generate synthetic intermediate frequency (IF) signals of a rectangular array. Subsequently, simulated 3-D radar images are generated using the backprojection algorithm. These images are compared with those of a nondispersive imaging system. Finally, two compensation methods using a phase correction method and an all-pass filter are explained, and their performance is compared.

Design of a Novel Split-Bowtie Slotted Multi-Resonant Antenna

This article demonstrates a novel design of a split-bowtie slotted multi-resonant antenna. The design process was inspired from previous research of integrating a slot of a similar profile to the outer boundary of a rectangular patch antenna. The followed approach presents steps of proposed antenna evolution, which starts with a bowtie-shape slotted antenna and a coaxial feed to a final design with a split-bowtie-shaped slot, and a double transmission line feed. Polar dimensions of the outer boundary (radii and angle) and slot profiles together with the dimensions of the feed, whether coaxial or transmission line, were considered as parameters for optimization. Four antennas were accordingly studied, which led to the final split-bowtie-shaped antenna IV. These designs were performed utilizing a special simulation package called "CST Microwave Suite" that included the optimizer "Genetic Algorithm". The final design offers 4 simultaneous bands from a single split-bowtie-shaped slot; a big advantage of unnecessary integration of a set of complicated slots on front and ground planes. Further, the antenna finds applications in mobile GSM and LTE bands 900/1800 MHz and 2.1 GHz, together with the satellite communications band 1.25 GHz. It is therefore simple, non-reconfigurable, easy to fabricate, designed on a single copper layer, with a low cost FR4 substrate and a plane copper ground.

Wideband high‐gain multiresonance antenna based on polarization‐dependent metasurface

AbstractIn this article, a novel polarization‐dependent metasurface (PDMS) structure is presented and applied to realize a wideband high‐gain antenna with multiple resonances. The PDMS element is obtained by cutting slots into the square patch unit cell of conventional metasurface (MS). Very different from the conventional MS structure, the proposed PDMS element exhibits different reflection phases and resonance frequencies, depending on the polarization state of the incident plane wave. By properly tailoring the reflection‐phase curves under different polarizations, a proper PDMS structure is introduced. Then, by arranging the PDMS elements along different orientations, a multiresonance radiator can be realized. When applying the proposed radiator to the slot‐coupled MS antenna, one broadband PDMS‐based antenna with multiple adjacent resonance frequencies can be realized by the combination of coupling slot‐mode and PDMS modes. For verification, a PDMS radiator with 4 × 4 unit cells is designed accordingly and applied to realize one C‐band broadband PDMS‐based antenna in a low profile (0.06 λ0). The measured results of the fabricated prototype PDMS‐based antenna exhibit a large –10 dB impedance bandwidth of 55% (4.31‐7.58 GHz), a maximum available gain of 10.898 dBi, and a 2‐dB gain bandwidth of 30.81% (5.1‐6.96 GHz).

Broadband Stable-Gain Multiresonance Antenna Using Nonperiodic Square-Ring Metasurface

A multiresonance antenna based on a nonperiodic square-ring metasurface (MS) is proposed, which has large bandwidth and stable radiation gain. The nonperiodic MS radiator is formed by several adjustable square-ring patches and fed by a microstrip line through a coupling slot. By properly adjusting the widths of these square rings, different resonance modes can be inspired for the MS according to the characteristic mode analysis. Combined with the resonance mode of the coupling slot, multiple adjacent resonance frequencies occur and thus realize a wideband and consistent radiation. For demonstration, a C-band wideband antenna based on the proposed 4 × 4 square-ring MS units with a low profile of 0.06 λ 0 is accordingly designed and fabricated. The measured results indicate a large impedance bandwidth of 54% (4–7 GHz) and an extremely stable gain with 2 dB gain bandwidth of 32% (4.76–6.54 GHz).

On the multi‐resonant antennas: Theory, history, and new development

A survey of multi-resonant antennas is comprehensively presented, with emphasis on theoretical framework, design approaches, and practical examples. This article begins with a brief history of the multi-resonant dipole theory, and then concentrates on the design approaches that have been developed to typical, basic antenna elements, for example, electric dipole antenna, slotline antenna, loop antenna, complementary dipole antenna, and microstrip patch antenna. Design examples for different practical applications are then raised. In final, the multi-resonant antenna design approach is summarized and compared to some relevant antenna design techniques.

Enhanced Second Harmonic Generation in Double‐Resonance Colloidal Metasurfaces

AbstractA key challenge for optical circuits is the ability to integrate nonlinear optical signal processing components such as optical modulators and frequency mixers at the chip scale. Optical antennas that focus light into nanoscale volumes can be utilized to shrink the footprint and increase the efficiency of these components. Multiresonant antennas that enhance both optical absorption and emission process are recently demonstrated to enable efficient nonlinear frequency conversion at the nanoscale and are promising as structures for second harmonic generation (SHG) and upconversion. Here, the ability of colloidal metasurfaces fabricated by self‐assembly as on‐chip platforms for enhanced SHG is demonstrated. These metasurfaces exhibit high spatial overlap of multiple surface plasmon modes whose frequencies can be independently tuned through appropriate design of colloidal and metasurface geometries. It is demonstrated that these bottom‐up structures rival lithographic nonlinear optical antennas in SHG efficiency, suggesting the potential for these colloidal metasurfaces in integrated on‐chip architectures.

Perspective: Strong microwave photon-magnon coupling in multiresonant dielectric antennas

Achieving quantum-level control over electromagnetic waves, magnetisation dynamics, vibrations, and heat is invaluable for many practical applications and possible by exploiting the strong radiation-matter coupling. Most of the modern strong microwave photon-magnon coupling developments rely on the integration of metal-based microwave resonators with a magnetic material. However, it has recently been realised that all-dielectric resonators made of or containing magneto-insulating materials can operate as a standalone strongly coupled system characterised by low dissipation losses and strong local microwave field enhancement. Here, after a brief overview of recent developments in the field, I discuss examples of such dielectric resonant systems and demonstrate their ability to operate as multiresonant antennas for light, microwaves, magnons, sound, vibrations, and heat. This multiphysics behavior opens up novel opportunities for the realisation of multiresonant coupling such as, for example, photon-magnon-phonon coupling. I also propose several novel systems in which strong photon-magnon coupling in dielectric antennas and similar structures is expected to extend the capability of existing devices or may provide an entirely new functionality. Examples of such systems include novel magnetofluidic devices, high-power microwave power generators, and hybrid devices exploiting the unique properties of electrical solitons.

Low-Profile Wideband Slot-Loaded Patch Antenna With Multiresonant Modes

A low-profile and wideband patch antenna is proposed for base station applications. In order to realize a wide band, two types of slots are adopted and three resonant modes are constructed within a band of interest. The mode analysis is conducted to clarify the wideband performance. The designed antenna has an impedance bandwidth of 52.7% (from 1.62 to 2.78 GHz) with a low-profile structure of ${\text{0.7}}\lambda _{0}\,\times \,{\text{0.47}}\lambda _{0}\,\times \,{\text{0.084}}\lambda _{0}$ , where $\lambda _{0}$ is the free-space wavelength at the center frequency. The measurement results of a prototype agree well with the simulations. The measured average gain is 6 dBi, and the radiation patterns remain stable in the required band with low cross polarization, low backlobes, and nearly identical E- and H-plane patterns. The proposed multiresonant antenna can cover six bands of wireless communication, such as DCS, PCS, UMTS, WLAN, LTE2300, and LTE2600, exhibiting great potentials in applications of multiband wireless communication systems.

Polarization Multiplexing of Fluorescent Emission Using Multiresonant Plasmonic Antennas.

Combining the ability to localize electromagnetic fields at the nanoscale with a directional response, plasmonic antennas offer an effective strategy to shape the far-field pattern of coupled emitters. Here, we introduce a family of directional multiresonant antennas that allows for polarization-resolved spectral identification of fluorescent emission. The geometry consists of a central aperture surrounded by concentric polygonal corrugations. By varying the periodicity of each axis of the polygon individually, this structure can support multiple resonances that provide independent control over emission directionality for multiple wavelengths. Moreover, since each resonant wavelength is directly mapped to a specific polarization orientation, spectral information can be encoded in the polarization state of the out-scattered beam. To demonstrate the potential of such structures in enabling simplified detection schemes and additional functionalities in sensing and imaging applications, we use the central subwavelength aperture as a built-in nanocuvette and manipulate the fluorescent response of colloidal-quantum-dot emitters coupled to the multiresonant antenna.

Surface-Enhanced Hyper-Raman Scattering: A New Road to the Observation of Low Energy Molecular Vibrations

The plasmon enhancement of molecular hyper-Raman scattering, the nonlinear counterpart of Raman scattering, which involves the absorption of two fundamental photons, is investigated with emphasis on low energy molecular vibrations. The two-photon excitation of the molecule is treated using its hyperpolarizability β, and the emission of the hyper-Raman photons is computed using a dipole emitter located at the molecule position. The electromagnetic response of the plasmonic systems is evaluated using a surface integral equation method, which makes possible considering both planewave and dipole excitations in a single formalism. Taking into account different geometries (including multiresonant antennas and silver heptamers supporting Fano resonances), the experimental parameters influencing the enhancement of the molecular hyper-Raman scattering are discussed in detail. In particular, it is shown that a good excitation at the fundamental stage is not sufficient for reaching a good enhancement factor and that...

Uwb multiresonance antenna with rejection of intelligent transport system band using a cross‐shaped conductor‐backed plane

ABSTRACTThis article presents an ultrawideband (UWB) microstrip monopole antenna with band‐notched function around 5.79–6.40 GHz to avoid any interference from the intelligent transport system (ITS). The proposed antenna consists of an ordinary square radiating patch, a feed‐line and a modified ground plane with pair of rotated H‐shaped slots and cross‐shaped conductor‐backed plane. By cutting a pair of rotated H‐shaped slots, additional resonances at higher frequencies are excited and hence much wider impedance bandwidth can be produced, which provides a wide usable fractional bandwidth of more than 135%. In the proposed design, to generate the ITS band‐stop performance, a cross‐shaped conductor‐backed plane is embedded in the ground plane. The proposed antenna can operate from 3.02 to 16.5 GHz with VSWR < 2 and with a rejection band around 5.79–6.40 GHz. The antenna has an ordinary square radiating patch, therefore, displays a good omnidirectional radiation pattern even at higher frequencies. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for UWB applications. The proposed monopole antenna configuration is simple, easy to fabricate and has a small size of 12 × 18 × 1.6 m3. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1641–1644, 2014

Small-Size Multiresonant Octaband Antenna for LTE/WWAN Smartphone Applications

A compact multiresonant antenna for octaband LTE/WWAN operation in the internal smartphone applications is proposed and discussed in this letter. With a small volume of 15×25×4 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , the presented antenna comprises two direct feeding strips and a chip-inductor-loaded two-branch shorted strip. The two direct feeding strips can provide two resonant modes at around 1750 and 2650 MHz, and the two-branch shorted strip can generate a double-resonance mode at about 725 and 812 MHz. Moreover, a three-element bandstop matching circuit is designed to generate an additional resonance for bandwidth enhancement of the lower band. Ultimately, up to five resonances are achieved to cover the desired 704-960- and 1710-2690-MHz bands. Simulated and measured results are presented to demonstrate the validity of the proposed antenna.

Soft computing techniques on multiresonant antenna synthesis and analysis

ABSTRACTThe synthesis and analysis of a multiresonant microstrip patch antenna using soft computing techniques are presented. The multiresonance is obtained via attaching inverted L‐shaped stubs to the radiated edges of the single frequency patch antenna. The physical geometry of the proposed antenna is synthesized using adaptive‐neuro‐fuzzy inference systems and the calculated dimensions are applied to the artificial neural network for the analysis process. The return loss and phase of the scattering parameters are computed. The modeled antenna provides 95% accuracy and sufficient results compared with the simulation and measurement results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2643–2648, 2013

Low profile slot antenna with dual band-notched function for UWB systems

In this article, a new multi-resonance slot antenna, with dual band-notched performance for UWB applications is presented. In the proposed structure, by cutting a rotated C-shaped slot on top of the ground plane, additional resonances are excited and hence much wider impedance bandwidth can be produced, especially at the middle band. To generate single band notch characteristics, we use a rotated C-shaped parasitic structure in the ground plane. Also to achieve dual band notch function, we insert a rotated C-shaped slot at square radiating stub. The measured results reveal that the presented dual band-notched slot antenna offers a very wide bandwidth with two notched bands covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX, and 4 GHz C bands. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:951–954, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27488

Compact UWB microstrip antenna with satellite down-link frequency rejection in X-band communications by etching an E-shaped step-impedance resonator slot

A multiresonance and UWB monopole antenna with frequency band-notched function in 7.25–7.75 for downlink of X-band satellite communication systems is presented.Proposed antenna consist of a square radiating patch with a pair of L-shaped slots, a feed-line with an E-shaped step-impedance resonator (SIR) slot, and a ground plane with a pair of L-shaped conductor-backed plane. In this design, by cutting a pair of modified L-shaped slots with variable dimensions on the radiating patch and also by inserting a pair of L-shaped conductor-backed plane, additional resonances are excited and hence much wider impedance bandwidth can be produced especially at the higher band 125% (2.95–13.36). To achieve a band-notched function an E-shaped SIR slot was inserted in the feed-line. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. The designed antenna has a small size of 12 × 18 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:922–926, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27456

Printed multi-resonant antenna embedding two inductors in radiating strips for internal mobile phone LTE/WWAN operation

In this article, a planar printed antenna for eight-band LTE/WWAN operation applied in the internal mobile phone has been proposed and studied. The presented antenna consists of a feeding strip and a coupling strip, where two chip inductors with different inductances are loaded in place. The desired lower bands of LTE700/GSM850/900 operation can be achieved by the coupling strip loading an inductor of 12 nH and a longer branch loading another inductor of 24 nH in the feeding strip, which provide a quarter-wavelength dual-resonance mode at 720 and 900 MHz. While a quarter-wavelength resonant mode at around 2.95 GHz can be generated by the shorter branch of the feeding strip, and other resonant modes at 1.92 and 2.23 GHz are contributed by the higher-order resonant modes of the long feeding strip and coupling strip, covering the desired upper bands of DCS1800/PCS1900/UMTS2100/LTE2300/2500 operation. In fact, the desired resonant lengths in the lower frequencies can be decreased, and impedance matching can be properly adjusted with the help of the two embedded inductors. Besides, a chip inductor of 2.2 nH is helpful for improving all the bands’ impedance matching. Detailed considerations of the antenna design and main parameters are studied and measured.

Octave-band, multi-resonance CPW-fed small slot antenna for UWB applications

A novel multi-resonance CPW-fed slot antenna, for UWB applications, is proposed. The proposed antenna consists of a modified fan-shaped radiating stub and a sprocket-shaped ground plane provides a wide usable fractional bandwidth of more than 155% (2.39–24.53 GHz). By inserting eight pairs of gear-shaped teeth on the sprocket-shaped ground plane, an additional eight resonances are excited and hence much wider impedance bandwidth can be produced. Unlike other antennas reported in the literature to date, the proposed antenna displays a good omnidirectional radiation pattern even at higher frequencies. The designed antenna has a small size of 30×30 mm2. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behaviour within the UWB frequency range.

Effective interpolation scheme for multi-resonant antenna responses: generalised Stoer–Bulirsch algorithm with adaptive sampling

Multiple analysis calls and high computational demand for each analysis present themselves as important bottlenecks in conducting practical electromagnetic design optimisation studies, particularly for complex material designs in metamaterial studies. To enable efficient re-analysis in such studies, the authors develop an algorithm for rational interpolation by generalising the Stoer-Bulirsch algorithm to allow for non-diagonal Neville paths rather than the known standard diagonal path to enhance its interpolation capability. The algorithm is then integrated to an adaptive sampling strategy that exploits the non-diagonality and finds an optimum Neville path that provides more efficient and reliable fittings for multi-resonance antenna response functions. The resulting technique is applied to return loss responses of antenna models with textured material substrates and complex conductor topologies. Interpolation results are compared with the performance of a standard Stoer-Bulirsch algorithm. Results show that the proposed generalised scheme outperforms the existing Stoer-Bulirsch technique in terms of computational accuracy by detecting resonances while still maintaining minimum number of support points. To demonstrate the capability of the proposed generalised algorithm, it is adapted to a large-scale antenna design optimisation example, achieving significant bandwidth performance enhancements for a novel antenna structure within practical timespans.