Reconfigurable Planar Antenna Research Articles

Design of Frequency-Reconfigurable Antenna on Dielectric and Magnetic Metamaterial Composite Substrate

Reconfigurable planar antennas are essential in multifunctional wireless communication devices. This letter presents the design of a frequency-reconfigurable patch antenna printed on a composite substrate made of a dielectric and a magnetic metamaterial (MMM). The MMM comprises magnetized ferrite slabs with embedded split-ring resonators (SRR). The constructive coupling between the resonances of the magnetized ferrites and SRR is optimized to achieve promising reconfigurable properties. The proposed frequency-reconfigurable antenna demonstrates a 158% increase in the frequency tuning range. Furthermore, the simulated results are experimentally verified, and the composite substrate shows slight effects on the antenna radiation characteristics.

Electronic Beam-Scanning Antenna Based on a Reconfigurable Phase-Modulated Metasurface.

Metasurfaces (MSs) have enabled the emergence of new ideas and solutions in the design of antennas and for the control of electromagnetic waves. In this work, we propose to design a directional high-gain reconfigurable planar antenna based on a phase-modulated metasurface. Reconfigurability is achieved by integrating varactor diodes into the elementary meta-atoms composing the metasurface. As a proof of concept, a metasurface prototype that operates around 5 GHz is designed and fabricated to be tested in an antenna configuration. The metasurface is flexibly controlled by different bias voltages applied to the varactor diodes, thus allowing the user to control its phase characteristics. By assigning judiciously calculated phase profiles to the metasurface illuminated by a feeding primary source, different scenarios of far-field patterns can be considered. Different phase profiles are tested, allowing us to, firstly, achieve a highly directive boresight radiation and, secondly, to steer the main radiated beam towards an off-normal direction. The whole design process is verified by numerical simulations and is validated experimentally by far-field antenna measurements. The proposed metasurface enables the design of directive flat antennas with beam-scanning characteristics without complex feeding systems and power-consuming phase shifters, and thus provides potential interests for next generation antenna hardware.

A triple band pattern reconfigurable planar antenna for 5G applications

Abstract This paper presents a triple-band planar antenna with diverse radiation patterns. The proposed planar antenna is a modified swastika shape with three fingers and the ground plane is a circle with rectangular slots etched on four sides radially. The slotted ground plane is loaded with Four PIN diodes to realign the surface current. Pattern reconfigurability is achieved at the triple bands by changing the states of the diode. The antenna operates in triple bands centered at 2.2, 2.9 and 3.5 GHz. The antenna is printed on FR4 Epoxy substrate. The simulated reflection coefficient is well below −10dB at resonant frequencies. The measured patterns and return loss are in very close agreement with the simulated results. This antenna can find potential applications in 5G systems.

Reconfigurable Pattern Patch Antenna for Mid-Band 5G: A Review

New requirements in communication technologies make it imperative to rehash conventional features such as reconfigurable antennas to adapt with the future adaptability advancements. This paper presents a comprehensive review of reconfigurable antennas, specifically in terms of radiation patterns for adaptation in the upcoming Fifth Generation (5G) New Radio frequency bands. They represent the key of antenna technology for materializing a high rate transmission, increased spectral and energy efficiency, reduced interference, and improved the beam steering and beam shaping, thereby land a great promise for planar antennas to boost the mid-band 5G. This review begins with an overview of the underlying principals in reconfiguring radiation patterns, followed by the presentations of the implemented innovative antenna topologies to suit particular advanced features. The various adaptation techniques of radiation pattern reconfigurable planar antennas and the understanding of its antenna design approaches has been investigated for its radiation pattern enhancement. A variety of design configurations have also been critically studied for their compatibilities to be operated in the mid-band communication systems. The review provides new insights on pattern reconfigurable antenna where such antennas are categorized as beam steering antenna and beam shaping antennas where the operation modes and purposes are clearly investigated. The review also revealed that for mid-band 5G communication, the commonly used electronic switching such as PIN diodes have sufficient isolation loss to provide the required beam performance.

A Bandwidth Reconfigurable Planar Antenna for UWB-Applications

A reconfigurable planar antenna design bandwidth operating in ultra wide band (UWB) applications with compact dimensions of (50 × 25× 1) mm3 is proposed. The switching capability is achieved by using a two PIN diodes F-shaped slot and a two narrow vertical slot. A defected ground structure is used to improve a range of frequency from 0.83 GHz to 5.24 GHz with an impedance bandwidth of 4.41 GHz. Moreover, the flow of current within the patch’s radiation is controlled via pair of PIN diodes situated at the centre with in the patch in the F-shape slot. A retractable patch antenna design is offered, and the bandwidth re-configurability is attained by manipulating the operational states of the PIN diodes. As result, we get a reconfigurable Circular Polarization (CP). Furthermore, the proposed antenna demonstrated an efficiency of 88.55% infrequencies operating at 3 dB Axial Ratio (AR) bandwidths. All achieved results shows that our antenna design is working much with 5G and UWB application.

Design of frequency reconfigurable planar antenna using artificial neural network

AbstractIn this paper, the design of frequency reconfigurable planar antenna by incorporation of metasurface superstrate (FRPA-MSS) is presented using an artificial neural network. The dual-layer radiating structure is created on a 1.524 mm thick Rogers RO4350B substrate board (εr = 3.48, tan δ = 0.0037). The candidate antenna is designed and analyzed using a high-frequency structure simulator (HFSS) tool. The transfer matrix method is employed for the successful retrieval of electromagnetic properties of the metamaterial. Frequency reconfiguration is achieved by placing the metasurface superstrate onto the rectangular patch antenna. A simplified ANN approach has been employed for the design of metasurface incorporated proposed antenna. Presented prototypes are characterized through experimental measurements. It is found from the practical observations that the proposed antenna effectively reconfigures the tuning range from 5.03 to 6.13 GHz. Moreover, the presented antenna operates efficiently with agreeable gain, good impedance matching, and stable pattern characteristics across the entire operational bandwidth. The experimental results obtained validate the simulated performance.

Pattern reconfigurable planar antenna array based on two circular defected ground structure

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Shape Memory Alloy-Based Frequency Reconfigurable Ultrawideband Antenna for Cognitive Radio Systems

The present work demonstrates a frequency reconfigurable planar antenna with narrowband and ultra-wideband (UWB) characteristics for cognitive radio systems. The designed antenna has a dimension of $60\times 58\times1.6$ mm3 with a ground plane made of nickel–titanium (Ni–Ti) shape memory alloy (SMA). The antenna operates at a flat condition with frequency 1.46 GHz. Bending the SMA ground plane at an angle of 200° with a transformation temperature of 66 °C. The same antenna operates over 3.4–10.2-GHz UWB range. This is due to the SMA phase transformation between martensite and austenite via resistive heating/cooling. The insertion of rectangular slits in the antenna creates dual band-notched characteristics 4.7–5.1 and 5.3–6.0 GHz with VSWR $S_{{11 {}}} dB. This creates a different working frequency leading to frequency reconfiguration. Details about the proposed antenna have been discussed along with measured and simulation results.

RFID ve GSM 900 MHz Uygulamaları için Elektronik Ayarlanabilir Yeni Bir Anten Tasarımı

In microwave systems, frequency tunable planar antennas have become common place as it is increasingly difficult to cover all the necessary frequency bands required. These antennas are low profile, conformable to planar and nonplanar surfaces, simple and inexpensive to manufacture using modern printed-circuit technology. The work presented in this paper proposes a electronically reconfigurable planar antenna by using only one varactor diode. Varactor diode from Skyworks Solutions Inc. (SVM1251) has been used as tuning element. It provides a tunable capacitance range from 53.65 to 2.79 pF with reverse voltages varying between 0 and 8 V. A 50 Ohm resistor as dummy load, and two 68 pF SMD capacitors are incorporated within the structure in order to protect the DC supply to Network Vector Analyzer from dc current, in addition to having an effect on the size reduction. Proposed antenna operate frequency between 400 MHz and 1116 MHz that include ultra-high frequency (UHF) for radio frequency identification (RFID) and Global Systems for Mobile Communications (GSM) applications. Proposed compact antenna having the overall physical size of 8 mm x 8 mm (0.0203λ x 0.0203 λ) is numerically modeled on FR4 substrate having loss tangent, dielectric constant and height of 0.025, 4.3, and 1.61 mm respectively in the CST Microwave Studio numerical calculation program over the frequency range from 300 MHz to 1.5 GHz. The proposed electrically tunable directional antenna has better return loss level higher than 25 dB with reduced size with novel geometrical structure in the operating frequency between 400 to 1116 MHz.

Design of phase-only reconfigurable planar array antenna in selected phi cuts using various meta-heuristic optimization algorithms

In this paper, a pattern synthesis based on a multiobjective optimization algorithm is proposed for the generation of a reconfigurable pencil/flat top dual-beam planar antenna array built using isotropic antenna elements in selected phi cuts. These beams claim the same amplitude excitations and differ from each other in phase excitations. Zero-phase excitations are used in pencil beam and these phases are updated with optimum phases for the flat top beam. All the excitations are obtained using Moth–flame optimization algorithm. With the support of the fitness functions, care is taken to control the expected values of the radiation pattern parameters to remain under certain fixed limit. In addition, synthesis is also done for the provision of a null in a particular direction for rejection of interference in the pencil beam in two different phi cuts. To suppress the mutual coupling effects, dynamic range ratio is kept under a threshold limit. Simulation results show the effectiveness of this proposed synthesis for phi cut planes. This algorithm is compared and proved to be better in many aspects over the standard meta-heuristic algorithms like Artificial Bee Colony and Imperialist Competitive algorithms in terms of performance parameters.

A multi-band switchable antenna for Wi-Fi, 3G Advanced, WiMAX, and WLAN wireless applications

AbstractThis paper presents a hexa-band frequency reconfigurable planar antenna, printed on a 1.6 mm thicker FR 4 substrate and backed by a truncated ground plane. The given antenna operates in four different frequency modes, depending on the state of the two lumped element switches. The proposed antenna works at six frequencies, 2.10, 2.40, 3.35, 3.50, 5.28, and 5.97 GHz. These frequency bands are dedicated to useful wireless applications, including 3G Advanced (2.10 GHz), Wireless Fidelity (Wi-Fi) (2.40 GHz), WiMAX (3.35 GHz), WiMAX (3.5 GHz), WLAN (5.28 GHz) and fixed-satellite and mobile satellite services (5.97 GHz). Satisfactory gain of 1.96, 2.20, 2.671, 2.81, 3.80, and 3.88 dBi, efficiency of 92.5, 94.5, 94.56, 95.0, 93.8, and 97.0% and bandwidth of 332, 485, 1020, 1080, 512, and 465 MHz has been obtained at 2.10, 2.40, 3.35, 3.50, 5.28, and 5.97 GHz, respectively. The modeling and simulations are conducted in CST MWS (2014). The simulated reflection coefficient and radiation pattern are validated in antenna measurement facility. In addition, the specific absorption rate of the antenna on a flat section of human body is also studied. The antenna is compact, low profile, and vastly suitable for multi-band wireless devices.

A Novel Structure of a Reconfigurable Printed Antenna for Wireless Applications

In this paper a new reconfigurable planar antenna design is proposed for wireless applications. The proposed antenna is based on PIN diodes in order to achieve the tuning of the frequency bands by changing the state (on/off) of the PIN diode. The PIN diodes were replaced by metallic tapes and the final circuit is mounted on an FR-4 substrate with a thickness of 1.58 mm, dielectric constant of 4.4, tangent loss of 0.025, fed by a microstrip line and its size is 56 X 40 mm2. The antenna is optimized and simulated by using CST-MW studio. The proposed reconfigurable antenna has been fabricated, and a good similarity is found between simulation and measurement results which permit to validate the designed antenna for many applications.

Ultra‐wideband reconfigurable radiation pattern antenna for diversity applications

A radiation pattern reconfigurable planar antenna operating at an ultra-wideband frequency range of 2.78–10.85 GHz is proposed. The proposed antenna is a combined structure of a monopole and a tapered slot, and it has two types of radiation patterns that can be chosen to be a monopole pattern or tapered slot pattern by controlling the states of four diodes. In addition, the shape of both radiation patterns is maintained across the whole operating frequency range. Details of the operation principle and the design considerations of the proposed antenna are presented.

Multiple‐parameter reconfiguration in a single planar ultra‐wideband antenna for advanced wireless communication systems

A compact frequency, pattern and polarisation reconfigurable planar ultra-wideband antenna is presented. The antenna is frequency reconfigurable to allow flexible functionality such as limiting the impact of out-of-band interferers if required in certain applications. Moreover, it provides basic pattern reconfiguration to enhance the scanning or the communication performance in future wireless applications by sensing interferers in the space domain and achieving pattern diversity to mitigate fading and increase signal-to-noise ratio. Another special feature of the proposed antenna is that its polarisation is reconfigurable at specific frequencies to generate circular polarised (CP) radiation. The antenna performance characteristics are verified through parametric simulations and measurements. The proposed antenna presents significant degrees of freedom in providing reconfigurable properties in frequency, radiation patterns and polarisation as compared to standard single-parameter reconfigurable antennas; therefore providing a flexible radio front-end for smart radio and wireless applications such as cognitive radio.

Design, Analysis and Comparison of Various MEMS Switches for Reconfigurable Planar Antenna

Design, Analysis and Comparison of Various MEMS Switches for Reconfigurable Planar Antenna

Wideband planar antenna with reconfigurable omnidirectional and directional radiation patterns

Proposed is a reconfigurable planar antenna that can generate omnidirectional and directional radiation patterns. The design has been tuned to resonate at 3.8 GHz and covers a bandwidth of several hundred MHz. Using RF switches, the antenna can generate five different radiation patterns: a single omnidirectional mode and four directional modes. Simulations and measurements were carried out and are in good agreement. The compact planar design, large operating bandwidth, and ability to create both omnidirectional and directional radiation patterns make this antenna suitable for small form factor wireless devices in next generation cognitive networks.

Smart Switch Metamaterials for Multiband Radio Frequency Antennas

We investigate metal–matrix composite metamaterials with embedded electrical switches made of shape memory nickel–titanium (Ni–Ti) for use in broadband radio frequency (RF) antennas. Experiments show that a Ni–Ti ribbon can form an electrical contact that opens and closes depending on the Ni–Ti phase being austenite or martensite. Finite element modeling of thermal gradients illustrates the phase change within the ribbon. Ultrasonic additive manufacturing (UAM), a solid-state additive manufacturing process, was utilized for embedding a Ni–Ti switch in an aluminum matrix. The aluminum matrix must have structural-grade strength for use in load-carrying antennas; thus, mechanical testing was conducted to quantify the longitudinal tensile, transverse tensile, and shear strength of the UAM matrix. Reconfiguration using a Ni–Ti switch was proven using a shape memory switch on a monopole RF antenna producing an operating frequency shift from 270 to 185 MHz when the switch is connected. A planar microstrip line was used to demonstrate signal transmission and reflection efficiency in a smaller, second switch. Transmission tests yielded less than −10 dB signal reflection proving the feasibility of reconfigurable planar antenna arrays using smart switches.

A NOVEL OF RECONFIGURABLE PLANAR ANTENNA ARRAY (RPAA) WITH BEAM STEERING CONTROL

A new antenna structure is formed by combining the concept of reconfigurable planar antenna array (RPAA) with the parasitic elements to produce beam steering patterns. The antenna has been integrated with the PIN diode switches that enable the beam to be steered in the desired direction. This has been done by changing the switch state to either on or off mode. In this work, a number of parasitic elements have been applied to the antenna, namely reflectors and directors. They are placed in between the driven elements, which is aimed to improve the beam steering angle. With such configuration, the main beam radiated by the array can be tilted due to the effect of mutual coupling between the driven elements and parasitic elements (reflectors and director). The unique property of this antenna design is that instead of fabricating all together in the same plane, the antenna's feeding network is separated from the antenna radiating elements (the patches) by an air gap distance. This allows reducing the spurious effects from the feeding line. The optimization results for the resonant frequencies of the antennas with variable air gap heights are also been studied. The antenna is made for 5.8 GHz. Good agreement is achieved between the simulation and measurement.

Low Cost Reconfigurable Landstorfer Planar Antenna Array

In this paper, we introduce a practical design for a Landstorfer planar antenna that can be implemented as a compact and low cost reconfigurable planar antenna array. The array, we propose, can have 360-degree coverage in azimuth and allows a wide variety of directive beams to be electronically selected while maintaining a simple structure, ease of manufacture and low cost with high efficiency. One of the possible applications for this array is in WLAN systems where high gain and low cost adaptable antennas promise increases in capacity and coverage. The array design utilizes key innovations in the design of Landstorfer antennas and feed/switching network. The Landstorfer antenna exhibits a high gain with 9.5 dBi and low mutual coupling between elements. A proposed reflector for the Landstorfer antenna is implemented and it allows the antenna array to be fabricated on a 2-layer PCB board. We also present a low cost feed/switching network which allows flexible control of the antenna patterns. The design makes use of PIN diodes as switching elements and a resonant inductor to improve the isolation of the PIN diodes. By integrating the antenna elements, feed/switching network and array configuration, a low cost reconfigurable Landstorfer planar array can be formed.

Advanced Utilization of Microwave Resonant Fields and Its Applications to Push-Push Oscillators and Reconfigurable Antennas

This paper presents an advanced and extensive utilization approach of microwave resonant fields, and the applications to push-push oscillators and reconfigurable planar antennas. The excellent coherency, synchronous harmonics and the degenerative orthogonal modes of electromagnetic field built up on microwave resonators are noticeable features in this approach. Another crucial point is the resonant field controllability that is especially essential feature for reconfigurable antennas in this paper. All the features can be realized by embedding semiconductor devices and/or IC's on a microwave resonator. Push-push oscillators and reconfigurable planar antennas are described as good examples of this approach. The push-push oscillators can generate very higher frequency signals due to the selective use of the 4th harmonic up to the 8th harmonic resonant fields, suppressing undesired harmonic signals. As a result, very high frequency band oscillators up to millimeter-wave bands with good suppression of undesired harmonic signals can be easily realized at very low cost by use of commercially available active devices for low frequency bands. The reconfigurable planar antennas are also demonstrated, where the boundary condition of the resonant field on planar antennas can be purposefully controlled to realize reconfigurable antenna performances by the semiconductor devices embedded on the patch as well. The orthogonal linear polarization controllable patch, the dual-band switching patch and the continuously frequency controllable patch have been demonstrated as the successful applications of this approach.