Integrated Antenna System Research Articles

An Integrated DRA-Based Large Frequency Ratio Antenna System Consisting of a MM-Wave Array and a MIMO Antenna for 5G Applications

An Integrated DRA-Based Large Frequency Ratio Antenna System Consisting of a MM-Wave Array and a MIMO Antenna for 5G Applications

Fully-Metallic Additively Manufactured Monolithic Double-Ridged Waveguide Rotman Lens in the K/Ka-Band.

This paper reports on the design and experimental validation of a fully-metallic double-ridged waveguide 10 × 10 Rotman lens additively manufactured as a single part. The wide band operation of this quasi-optical beamformer enables us to cover the uplink and downlink frequencies allocated to satellite communications in the K/Ka-band, from 17.3 GHz to 30 GHz. The feeding port design was adjusted to enable vertical printing, thus minimizing the use of supporting structures. A prototype was manufactured and tested. The reported results indicate losses in the range of 0.5 dB in the lower-frequency band and 0.8 dB in the upper-frequency band, including the waveguide transitions added for test purposes. The measured reflection and coupling coefficients remain below -11.5 dB over the operating band. The standard deviation of the residual phase error across the array ports is below 5° in simulation and below 10° in measurements. Array factors synthesized using the scattering parameters confirm the good stability of the beamforming functionality over the wide frequency band analyzed. This monolithic design is a promising step toward more integrated antenna systems, such as a compact dual-stack configuration for planar array design.

A novel wideband cube resonator antenna with metasurfaces

AbstractA novel wideband cube resonator antenna (CRA) composed of metasurfaces is proposed in this letter, which can be applied to an active integrated antenna system. The resonant region of the CRA is formed by six metasurfaces of 4 × 4 arrays. The six surfaces can be equivalent to ideal electric walls. With the improved feeding slot, the dominant mode TE1δ1 and high‐order mode TE1δ3 are effectively excited, which enables a wideband and high gain performance for the CRA. A prototype of the antenna is fabricated and measured to verify the antenna design principle. The antenna has a measured impedance bandwidth of 17.0% (4.42–5.24 GHz) and a peak gain of 8.51 dBi, and good agreement between the simulated results and measured results is obtained. The proposed CRA shows resonant mode and radiation performance similar to those of traditional dielectric resonator antennas, which provides a new technique for the design of resonator cavity antennas.

A compact and economical AMC backed antenna solution for wearable biomedical applications

AbstractA rectangular monopole antenna with an extended ground, excited by Coplanar Waveguide (CPW) and backed by a 6 × 6 array of fractal artificial magnetic conductor (AMC) unit cells, resonating at 5.8 GHz in Industrial, Scientific, and Medical (ISM) band, is presented in this manuscript. To attain the objective of proposing a compact and economical antenna solution for employment in wearable biomedical domain, a novel approach of utilizing both surfaces of the same dielectric for engraving antenna element as well as AMC array is adopted. It results in the elimination of layers of expensive substrate (RO3003) and of thick separator (foam) between antenna and AMC array. During measurement in open space, the proposed antenna system exhibited an impedance bandwidth of 570 MHz with a gain of 7.9 dBi. While a total realized gain of 7.5 dBi, amounting to a gain enhancement of about 3 dB as compared to that of monopole alone, is observed when the integrated antenna system is placed just over a three-layer rectangular human body equivalent model. Specific absorption rate values, as calculated at 5.8 GHz and averaged over 1 and 10 g of human tissue, are 0.0117 and 0.00244 W/kg, respectively. Obtained results strongly advocate the use of the proposed antenna system in smart wearable healthcare devices.

A Novel Integrated UWB Sensing and 8-Element MIMO Communication Cognitive Radio Antenna System

In this article, a cognitive radio (CR) integrated antenna system, which has 1 sensing and 24 communication antennas, is proposed for better spectrum utilization efficiency. In the 24 communication antennas, 3 different operating band antennas are realized with an 8-element MIMO configuration. The sensing antenna linked to port 1 is able to sense the spectrum that ranges from 2 to 12 GHz, whereas the communication 8-element MIMO antennas linked with ports 2 to 9, ports 10 to 17 and ports 18 to 25 perform operations in the 2.17–4.74 GHz, 4.57–8.62 GHz and 8.62–12 GHz bands, respectively. Mutual coupling is found to be less than −12 dB between the antenna elements. Peak gain and radiation efficiency of the sensing antenna are better than 2.25 dBi and 82%, respectively, whereas the peak gains and radiation efficiencies of all communication antennas are more than 2.5 dBi and 90%, respectively. Moreover, diversity characteristics of the MIMO antenna are assessed by parameters such as DG, ECC and CCL. It is found that ECC and CCL are less than 0.42 and 0.46 bits/s/Hz, respectively, and also DG is more than 9.1 dB.

High isolation multiport integrated antenna system for cognitive radio applications

ABSTRACT A five port integrated antenna with high isolation for cognitive radio (CR) application was investigated in this study. The design approach involves both the state of operation in terms of ultra-wideband (UWB) and narrowband (NB), where the former is for sensing and the latter is for the sake of communication. The antenna in UWB state comprises an elliptical patch with a narrow cut on the top whereas four simple comb-like patterns are used to perform the task in NB range. In three of the NB antennas, Complementary Split Ring Resonators (CSRR) are used for impedance matching, in contrast to a Double Circular Ring Resonator (DCRR) in another NB antenna. In order to achieve remarkable inter port isolation, two meander lines of same electrical length are introduced between UWB and NB antennas where the first meander line (ML1) is positioned parallel and the second meander line (ML2) is tilted by an angle of 30° with respect to UWB. The potential outcome of the proposed design senses UWB spectrum from 1.9 GHz − 11.77 GHz along with seven communication tasks simultaneously in terms of single and dual band operations with remarkable gain and high isolation of <-22 dB in all ports.

Analysis of integrated UWB MIMO and CR antenna system using transmission line model with functional verification

This paper discusses the equivalent circuit model and functional verification of an integrated antenna system as its main focus. The integrated antenna system consists of two independent antenna systems, namely the Cognitive Radio antenna and the Ultra Wide Band Multiple Iinput Multiple Output antenna. This article is split into two parts: The first part discusses the equivalent circuit of an integrated antenna system by optimizing the RLC values. The developed lumped equivalent circuit model produces the NB resonant frequencies, which is the same as the S-parameter obtained through EM simulation. The second part of this paper aims to discuss the experimental verification of an integrated CR antenna system with Bayesian learning-based spectrum sensing algorithms using Universal Software Radio Peripheral devices. Real-time sensing and communication functionalities are visualized in the LABVIEW monitor. The integrated antenna system is fabricated and measured after the simulation.

A multi‐port, narrow‐wide band achievable, reconfigurable antenna for cognitive radios

This paper aims to propose a 4-port integrated antenna system that is capable of exhibiting ultra wideband (UWB) and narrowband (NB) characteristics using excitation switching reconfiguration. In line with the requirements of the Cognitive Radio (CR), the UWB functionality makes the antenna capable of spectrum sensing and the NB feasibility allows the antenna to communicate with the spectrum. The proposed antenna is having a compact dimension of 40 mm × 35 mm × 1.6 mm and is printed on FR4 substrate with relative permittivity of 4.4. The antenna performance is analyzed as 3 scenarios. In all three, the antenna is found to cover the entire UWB spectrum approved by the federal communications commission (FCC), from 3.1 to 10.6 GHz. In addition to the UWB characteristics, each scenario provides at least one NB characteristic. In Scenario 1, the NB antenna 1 provides coverage from 6.87 to 8.67 GHz whereas, in Scenario 2, the NB antenna 2 provides dual-band coverage from 2.99 to 4.27 GHz and 8.47 to 11.40 GHz. In Scenario 3, the NB antenna 3 operates in a single band from 4.09 to 7.09 GHz. Isolation between the antennas is found to be less than −15.9 dB in all the Scenarios. The lumped equivalent models of NB antennas are simulated and optimized in Applied Wave Research (AWR) software to match the antenna S-parameters at their resonance frequencies. The simulated and measured results are in good agreement. The comparative analysis of the antenna with the previous works in the same area is also included in this paper.

An integrated antenna for cognitive radio wireless sensor networks and HD video transmission applications

This article introduces an integrated polarization divesity cognitive radio (CR) and Ultrawide Band (UWB) Multiple Inputs and Multiple Output (MIMO) antenna systems for CR wireless sensor networks (CR-WSN) and short-range HD video transmission applications. This proposed integrated antenna system's main purpose is to overcome the impediments of frequency re-configurable UWB/Narrow Band (NB) antenna system. The proposed integrated system consists of two antenna systems: the CR antenna and the UWB MIMO antenna system. The first part of the integrated antenna system is the CR antenna that comprises vertical and horizontal oriented UWB antennas to sense the spectrum and four NB antennas for communication purposes. The second part of the integrated antenna system is a 2 × 2 MIMO antenna that comprises a veritical and horizontal oriented UWB antenna with notch characteristics for MIMO applications. High isolation is achieved without using a decoupling structure by placing radiators in the horizontal and vertical planes. The proposed integrated 3D antenna system is designed with a compact size of 50 × 50 mm2. The antenna's essential parameters, such as the reflection coefficient, mutual coupling, peak gain, the radiation pattern, and radiation efficiency, are analyzed to evaluate the antenna's performance. The proposed integrated antenna system is suitable for off-device applications in industries or Laboratories. The real-time implementation of CR-WSN and short-range wireless HD video transmission applications are demonstrated using National Instruments (NI) Universal Software Radio Peripheral (USRP) and CC2538 kit.

An Integrated Tri-Band Antenna System With Large Frequency Ratio for WLAN and WiGig Applications

Integrated antenna systems that support multiple wireless standards (microwave and millimeter-wave bands) have become a pivotal issue in future wireless networks. The joint implementation of these frequency bands that can provide long-range and short-range radio accesses within a wireless system is desired. However, due to the large frequency difference between different bands, it is hard to realize with limited space. To solve this problem, a novel topology of combining a stacked patch antenna at 2.4/5 GHz bands and a magnetic-electric (ME) dipole antenna at 60-GHz with shared-aperture is developed in this article. Based on the methodology of aperture reuse, a highly-integrated tri-band antenna system with a large frequency ratio and good isolation is reasonably designed, featuring the same linear polarization and broadside radiation patterns. For experimental demonstration, an elaborate prototype is fabricated and tested. The measured -10-dB impedance bandwidths among the three bands can satisfy the criterions of the IEEE 802.11 b/a/ad for wireless local area networks (WLANs, 2.4-2.485 GHz and 5.15-5.85 GHz) and wireless gigabit (WiGig, 57-64 GHz) operations.

Monitoring the radio frequency spectrum based on an integrated antenna system

Currently, the active use of the electromagnetic resource associated with the development of systems and means of radio communications and radio engineering, as well as various electronic and electromechanical systems, leads to a significant appearance of an additional electromagnetic background, complicating the already difficult state of the noise environment and exacerbating the problems of electromagnetic compatibility.

Anisotropic Metasurface-Based Beam-Scanning Dual-Polarized Fan-Beam Integrated Antenna System

This paper presents a novel anisotropic metasurface (AMS)-based integrated antenna system to facilitate dual-polarized fan-beam patterns with independent beam-scanning ability. In the proposed configuration, the antenna subsystem comprises a specially designed differentially fed microstrip patch antenna (source antenna) along with a polarization rotator (PR). The differential antenna arrangement is realized using a square shaped microstrip patch capacitively coupled with two metallic strips, which are connected to a specially designed wideband hybrid coupler using two metallic vias for the microstrip feeding. This source antenna is loaded with a PR by placing it at a height of $0.35\lambda _{0}$ from the radiating aperture. The PR comprised two identical metallic layer patterns, separated by two substrates. Depending upon the relative orientation of these layers, the polarization of the linearly polarized impinging spherical electromagnetic (EM) waves (originating from the source antenna) either remains preserved or gets rotated by 90° while transmitting through this PR. After realizing the antenna subsystem, a novel AMS lens is designed and placed above the PR. The proposed AMS lens is realized by integrating two cylindrical MS (CMS) lenses, $\text {CMS}_{Y}$ and $\text {CMS}_{X}$ . This integration provides a unique phase profile to the AMS lens, thus introducing appropriate phase correction to the incident orthogonally polarized spherical EM waves along their respective polarization direction. The proposed configuration of AMS lens, thus, results into formation of the independent dual-polarized fan-beam radiation beams. Finally, the steering of the generated fan-beams along the direction of their respective polarization is facilitated using the proposed system by translating the AMS lens parallel to the source antenna.

Spectrum sensing and communication functionalities verification in cognitive radio

SummaryThis paper is intended to discuss hardware setup implementation for realizing the spectrum sensing and communication functionalities of a five‐port integrated ultrawideband and narrowband antenna system. The five‐port integrated antenna system consists of one ultrawideband antenna and four narrowband antennas. The ultrawideband antenna is used for spectrum sensing in cognitive radio, whereas the four narrowband antennas are used for communication. In order to validate functionalities of the antennas, their spectrum sensing and communication performance is verified using an arbitrary waveform generator, real‐time signal analyzer, and Universal Software Radio Peripheral. The ultrawideband antenna is able to sense the various frequencies transmitted by the arbitrary waveform generator. These transmitted signals from the arbitrary waveform generator are treated as busy spectrum channels in the cognitive radio environment. The narrowband antennas are able to perform communication by transmitting the signals at identified spectrum holes. The sensed signals are observed on a real‐time signal analyzer, and the communication signals are viewed in LabVIEW software for which a real‐time signal reception algorithm is used. This signal reception is performed using Universal Software Radio Peripheral.

An Integrated Slot-Based Frequency-Agile and UWB Multifunction MIMO Antenna System

This letter presents an integrated multiple-input–multiple-output (MIMO) antenna solution for cognitive radio (CR) front ends. The antenna consists of the four-element slot-line-based frequency-reconfigurable (FR) MIMO antenna integrated with a four-element half-annular slot-based ultrawideband (UWB) multifunction MIMO antenna system, printed on the same substrate. Each FR antenna element is loaded with a unique split-ring resonator to achieve multiband operation. A wide frequency sweep over multibands is achieved using one varactor diode per antenna element, thus covering 1.495–2.18, 3.35–4.08, and 4.15–4.49 GHz. The proposed multipurpose UWB antenna senses the spectrum from 1.48 to 4.56 GHz, as well as it can be utilized to serve as an UWB MIMO antenna system. The proposed antenna has planar and compact structure with total size of 200 $\times\; \text{150}\;\times$ 0.76 mm $^3$ , thus is suitable to be used for tablet PC applications in second-generation CR platforms.

An Integrated Antenna System for 4G and Millimeter-Wave 5G Future Handheld Devices

In this work, an integrated antenna system with Defected Ground Structure (DGS) is presented for Fourth Generation (4G) and millimeter (mm)-wave Fifth Generation (5G) wireless applications and handheld devices. The proposed design with overall dimensions of 110 mm × 75 mm is modeled on 0.508 mm thick Rogers RT/Duroid 5880 substrate. Radiating structure consists of antenna arrays excited by the T-shape 1 × 2 power divider/combiner. Dual bands for 4G centered at 3.8 GHz and 5.5 GHz are attained, whereas the 10-dB impedance bandwidth of 24.4 - 29.3 GHz is achieved for the 5G antenna array. In addition, a peak gain of 5.41 dBi is demonstrated across the operating bandwidth of the 4G antenna array. Similarly, for the 5G mm-wave configuration the attained peak gain is 10.29 dBi. Moreover, significant isolation is obtained between the two antenna modules ensuring efficient dual-frequency band operation using a single integrated solution. To endorse the concept, antenna prototype is fabricated and far-field measurements are procured. Simulated and measured results exhibit coherence. Also the proposed design is investigated for the beam steering capability of the mm-wave 5G antenna array using CST®MWS®. The demonstrated structure offers various advantages including compactness, wide bandwidth, high gain, and planar configuration. Hence, the attained radiation characteristics prove the suitability of the proposed design for the current and future wireless handheld devices.

Four port MIMO integrated antenna system with DRA for cognitive radio platforms

An integrated four-port multi input multi output (MIMO) system with Cylindrical Dielectric Resonator Antenna (CDRA) for Cognitive Radio (CR) application is investigated. In this study the proposed design performs dual state operation i.e ultrawideband (UWB) and narrowband (NB) functionality with modified feeding mechanism, where the feeding line of UWB antenna is made orthogonal to NB CDRA. In UWB state the proposed integrated antenna consisting of two port circular radiators, excited by micro-strip transmission line. In NB state two CDRAs are integrated on the UWB radiators where the current density is effectively low. The DRAs are excited by aperture coupled orthogonal T feed micro-strip transmission line to perform the triband operation at targeted bands. The proposed integrated MIMO system occupies a compact total area of 0.18λ02(λ0 is the highest operating wavelength) with isolation less than −15 dB among all ports. The design approach is verified by fabricating the antenna prototype and the performances are experimentally evaluated in terms of S parameter, radiation pattern and gain. Moreover, the MIMO performance metrics in terms of Envelope correlation coefficient (ECC), diversity gain (DG) and mean effective gain (MEG) are also evaluated for satisfactory diversity performance.

An Integrated Four-Element Slot-Based MIMO and a UWB Sensing Antenna System for CR Platforms

This communication presents a novel integrated antenna system for cognitive radio (CR) applications. The design consists of a compact four-element reconfigurable annular slot-based multiple-input-multiple-output (MIMO) antenna system integrated within an ultrawideband (UWB) sensing antenna. All the antenna elements are planar in structure and designed on a single substrate ( RO-4350 ) with dimensions $60\times 120\times 1.5$ mm3. The frequency reconfigurable slot-based MIMO antenna system is tuned over a wide frequency band from 1.77 to 2.51 GHz while the UWB sensing antenna is covering from 0.75 to 7.65 GHz The proposed antenna system is suitable for CR enabled wireless devices. The envelop correlation coefficient did not exceed 0.248 in the entire operating band of the MIMO antenna part. The maximum measured gain of the MIMO antenna is 3.2 dBi with a maximum efficiency of 81%.

A Two Concentric Slot Loop Based Connected Array MIMO Antenna System for 4G/5G Terminals

In this paper, an integrated design with a multiple-input multiple-output (MIMO) antenna system for fourth generation (4G) and fifth generation (5G) applications is presented. The proposed design contains a two-element slot-based MIMO antenna system for 4G and a connected antenna array (CAA)-based two-element MIMO antenna system for a potential 5G band. Two rectangular loops are etched on the periphery of the ground plane. The top and bottom portions of the thin loops act as the two 4G MIMO antennas, while parts of their sides are acting as 5G arrays. The antenna system is fabricated on a commercially available Roger 4350 substrate with $\epsilon _{r}$ equal to 3.5, while the dimensions of the board are $100\times 60 \times 0.76$ mm3 representing a typical smart phone back plane size. The integrated antenna system covers multibands at 4G with a combined bandwidth of 1.565 GHz (−6 dB BW) in addition to the band between 16.50 and 17.80 GHz for 5G. The design is planar, low profile, simple, and compact in structure making suitable for wireless handheld devices and mobile terminals. The measured gain at 3.46 GHz was at least 2.22 dBi and at 17 GHz was 8 dBi for the 4G and 5G MIMO antenna systems, respectively. The envelope correlation coefficient was also calculated from the measured 3-D patterns and showed good MIMO performance. This is the first integrated 4G/5G MIMO antenna system with below 6 GHz and above 10-GHz covered bands using CAA.

A Compact Dual-Band Antenna Enabled by a Complementary Split-Ring Resonator-Loaded Metasurface

In this paper, the design of a compact dual-band antenna with operational bands centered at 1.9 and 2.5 GHz is introduced and validated numerically as well as experimentally. The proposed antenna is comprised by placing a monopole feeding antenna above an engineered multilayer metasurface (MS) which functions as an artificial ground plane. Moreover, complementary split-ring resonator structures are incorporated into the multilayer MS design to realize the dual-band operation of the proposed monopole-MS integrated antenna system. Dispersive analysis of the MS unit cell reveals the underlying radiation mechanism of the antenna. It is observed that the designed MS resonates in both frequency bands with a resonance mode pattern resembling that of the $TM_{10}$ mode of a rectangular patch antenna, thereby yielding a broadside radiation pattern in both bands. The overall footprint of the antenna is only $\mathrm {0.062}{\lambda }_{0}^{2}$ , where ${\lambda }_{0}$ is the free space wavelength at 1.9 GHz. Importantly, by using the proposed artificial ground plane, even with a highly miniaturized form factor, the antenna still maintains a peak gain of above 5 dBi and a front-to-back ratio higher than 6 dB within the two operational bands.

A novel very wideband integrated antenna system for 4G and 5G mm‐wave applications

AbstractIn this work, a novel very wideband 4‐element monopole based multiple‐input multiple‐output (MIMO) antenna system with single connected antenna array (CAA) is presented. The CAA is based on a single slot which is etched on the ground plane. A 2 × 1 power divider/combiner is used to excite the slot to act as a CAA. The proposed design covers the 4G bands between 1850 and 3700, and the 28 GHz 5G band. The covered bandwidths are 1462 and 240 MHz from 1843 to 3305 MHz and 3500 to 3740 MHz, respectively, for 4G applications. A bandwidth of 1.22 GHz from 27.5 to 28.72 GHz is obtained for 5G applications. The proposed antenna system is designed on a double layer RO4350B substrate with height of 0.76 mm and dielectric constant of 3.5. The total size of the design is 115 × 65 × 0.76 mm3. It is compact, low profile and suitable for wireless handheld devices. The MIMO performance metrics such as isolation and ECC are evaluated and good agreement between simulations and measurements is achieved.