Polarization Diversity Antenna Research Articles

Compact, Wideband, Dual-Band Polarization and Pattern Diversity Antenna for Vehicle Communications

A new design approach of dual-band polarization and pattern diversity antenna for vehicle communications is presented. This antenna consists of three essential parts: Monopole array, swastika-shaped gap-coupled patch, and customized L-shaped driven dipole. Firstly, the monopole array composed of four monopoles beneath the patch, is excited by dipole-induced patch mode of the swastika-shaped gap-coupled patch so as to realize bidirectional beam in the upper band. Secondly, the swastika-shaped gap-coupled patch is reused as the main radiator of the lower band to achieve wideband broadside right-handed circular polarization (RHCP) radiation, which is excited by a pair of customized parallel-lines-fed L-shaped driven dipoles. Finally, two short-circuited branches are etched in the long arm of the L-shaped driven dipole, bringing in the out-of-band suppression improvement between the lower and upper bands. In order to verify the developed design method, a dual-band antenna with different polarization and radiation properties over two bands was designed, fabricated, and tested. Measured results indicate that the developed antenna with a compact transversal size of 0.36λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> *0.36λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> radiates broadside RHCP electromagnetic wave in 3.55-4.25GHz and bidirectional vertical polarization (VP) in 5.62-6.38GHz, which covers C-band and DSRC-band, and especially serves as a promising candidate for applications in both vehicle-to-satellite (V2S) and vehicle-to-everything (V2X) communications.

Diversity Glass Antennas for Tri-Band WiFi Applications

This paper investigates two novel polarization- and pattern-diversity glass dielectric resonator antennas (DRAs), both of which are for tri-band (2.4, 5.2, and 5.8 GHz) wireless fidelity (WiFi) applications. It also investigates what type of diversity antenna is most suitable for WiFi router applications by comparing the two DRAs, along with a new space-diversity glass DRA. These three diversity glass DRAs are also compared with a commercial space-diversity monopole pair to benchmark the performance of the glass DRA in WiFi router applications. In our polarization-diversity antenna, a double-port feeding scheme is developed to excite different DRA modes. The frequencies of the DRA modes are tuned by using a stepped DRA. For the pattern-diversity design, a stacked DRA is introduced to broaden the bandwidth for both the conical and broadside radiation modes. All three of the new diversity antennas were fabricated and measured to verify the simulations. In our experiment, the bit error rate (BER) of the three diversity glass antennas and the reference space-diversity monopole antenna was also measured, and the results are compared and discussed. It is found that the polarization-diversity omnidirectional DRA has the most stable BER among the three.

New Design of a Compact 1×2 Super UWB-MIMO Antenna for Polarization Diversity

This paper proposes a new design of compact coplanar waveguide (CPW) fed -super ultra-wideband (S-UWB) MIMO antenna with a bandwidth of 3.6 to 40 GHz. The proposed antenna is composed of two orthogonal sector-shape monopoles (SSM) antenna elements to perform polarization diversity. In addition, a matched L-shaped common ground element is attached for more efficient coupling. The FR-4 substrate of the structure with a size of 23 × 45 × 1.6 mm3 and a dielectric constant of 4.3 is considered. The proposed design is simulated by using CST Microwave Studio commercial software. The simulation shows that the antenna has low mutual coupling (|S21| &lt; -20 dB) with |S11|&lt;−10 dB, ranging from 3.6 to 40 GHz. Envelope correlation coefficient (ECC) is less than 0.008, diversity gain (DG) is more than 9.99, mean effective gain (MEG) is below – 3 dB, and total active reflection coefficient (TARC) is less than -6 dB over the whole response band is reported. The proposed MIMO antenna is expected efficiently cover the broadest range of frequencies for contemporary communications applications.

A monopole polarisation diversity antenna for high density packaging MIMO applications

Purpose This paper aims to propose a single element, dual feed, polarisation diversity antenna. The proposed antenna operates from 2.9 to 10.6 GHz for covering the entire ultra-wideband (UWB) frequency range. The antenna is designed for usage in massive multiple input multiple output (MIMO) and closed packaging applications. Design/methodology/approach The size of the antenna is 24 × 24 × 1.6 mm3. The radiating element of the antenna is derived from the Sierpinski–Knopp (SK) fractal geometry for miniaturization of the antenna size. The antenna has a single reflecting stub placed between the two orthogonal feeds, to improve isolation. Findings The proposed antenna system exhibits S11 &lt; −10 dB, S21 &lt; −15 dB and stable radiation characteristics in the entire operating region. It also offers an envelope correlation coefficient &lt; 0.01, a diversity gain &gt; 9.9 dB and a capacity loss &lt; 0.4 bps/Hz. The simulated and measured outputs were compared and results were found to be in similarity. Originality/value The proposed UWB-MIMO antenna has significant size reduction through usage of SK fractal geometry for radiating element. The antenna uses a single radiating element with dual feed. The stub is between the antenna elements which provide a compact and miniaturized MIMO solution for high density packaging applications. The UWB-MIMO antenna provides an isolation better than −20 dB in the entire UWB operating band.

Battery-Free Wireless Light-Sensing Tag Based on a Long-Range Dual-Port Dual-Polarized RFID Platform.

Radio frequency identification (RFID) represents an emerging platform for passive RF-powered wireless sensing. Differential Multi-port RFID systems are widely used to enable multiple independent measurands to be gathered, or to overcome channel variations. This paper presents a dual-port/dual-integrated circuit (IC) RFID sensing tag based on a shared aperture dual-polarized microstrip antenna. The tag can be loaded with different sensors where the received signal strength indicator (RSSI) of one IC is modulated using a sensor, and the other acts as a measurand-insensitive reference, for differential sensing. The 868 MHz tag maintains a minimum unloaded read range of 14 m insensitive to deployment on metals or lossy objects, which represents the longest reported range of a multi-port RFID sensing tag. The tag is loaded with a light-dependent resistor (LDR) to demonstrate its functionality as a battery-less wireless RFID light sensor. Following detailed RF characterization of the LDR, it is shown that the impedance, and consequently the RSSI, of the sensing tag are modulated by changing the light intensity, whereas the reference port maintains a mostly unchanged response for a correlated channel. The proposed tag shows the potential for channel variations-tolerant differential RFID sensing platforms based on polarization-diversity antennas.

A Dual Orthogonal Fed Monopole Antenna for Circular Polarization Diversity

A monopole antenna with circular polarization diversity and high isolation is proposed in this paper. The proposed antenna consists of two bent monopole antennas and a partial ground plane. Two monopole antennas are implemented on opposite planes with respect to the ground plane. The ground plane is a right-angled isosceles triangle, and the antenna is located at one end of the ground plane. Circular polarization (CP) characteristics are obtained using this structural asymmetry. In the proposed structure, the resonant frequency at S11 is controlled by the antenna length, and the null frequency at S21 (isolation) is controlled using the bending angle of the monopole and the distance between the two antennas. From the measured results, the CP operating bandwidth of the proposed antenna is 13.8% (1.76–2.02 GHz). The measured isolation is –50 dB at the resonant frequency and –20 dB within the operating bandwidth.

An Arrangement for Four-Element MIMO DRA With Complementary CP Diversity

An integrated four-element dielectric resonator-based multiple-input-multiple-output (MIMO) polarization diversity antenna is proposed in this letter. The MIMO antenna comprises two microstrip-slot fed dielectric resonator antenna (DRA) elements and two conformal open-loop fed DRA elements. These two different types of antenna elements are intended to radiate in two opposite directions to reduce the field components' interference. This aspect can offer a reliable wireless connection. Also, circular polarization diversity is implemented between the diagonally placed antenna elements to improve the isolation and diversity performance. The measured overlapping impedance bandwidth (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ii</sub> <; -10 dB) of 500 MHz (3.22-3.72 GHz) is attained for the proposed MIMO antenna with interport isolations of more than 15 dB throughout the usable frequency band. The proposed MIMO antenna acquires a measured overlapping axial ratio (AR) bandwidth (AR <; 3 dB) of 200 MHz (3.34-3.54 GHz), which covers the 3.4 GHz carrier frequency for the vehicle-to-vehicle and vehicle-to-infrastructure applications.

Electronically Controlled Reconfigurable Antenna for Polarization Diversity

This article describes a novel design for implementing polarization reconfiguration in a simple patch antenna for Wireless Body Area Networks (WBANs) operating at 5.8 GHz industrial, scientific, and medical frequencies. The radiating patch is excited by a quarter-wave matched microstrip line in this structure. The cutting of two quadrilateral-shaped slots on the radiator divides the structure into a square radiating patch and two small triangular patches. Two diodes are embedded across the slot to connect or disconnect the triangular patch from the larger patch. Consequently, the antenna can be reconfigured between linear and Circular Polarization (CP). The antenna is simple and has a compact size of 27 mm × 20 mm × 1.6 mm. A prototype has been made and tested. The result reveals that the antenna produces circular polarization at 5.8 GHz with a good impedance bandwidth of 6.2% (5.56-5.93 GHz). In addition, it has an excellent axial ratio bandwidth of 2.8% (5.71-5.88 GHz). A human tissue model is used in the simulation in order to study the on-body performance of the antenna. The findings indicate that this design is advantageous for off-body communication and significantly improves the reliability of wireless systems.

Design and packaging of polarization diversity 3D-UWB MIMO antenna with dual band notch characteristics for vehicular communication applications

In this article, the design, fabrication, testing, and packaging of a Substrate Integrated Waveguide(SIW) based polarization diversity 3D eight-port Ultra-Wideband (UWB) MIMO antenna introduced with dual-band notch characteristics for vehicular communication applications. In this proposed UWB MIMO design, we employed a SIW technique to achieve UWB bandwidth with a compact size of 60 × 60 mm3. The SIW based metallic via integrated with L-shaped parasitic slot stub and radiator to notch the WLAN and L-shaped stub connected at the ground plane to notch the X-band. The SIW based radiators are placed in the vertical and horizontal plane to realize the polarization diversity. In addition to providing polarization diversity, the antenna’s direction also contributes a reliable link with communication equipment. The antenna performance metrics such as reflection coefficient(Sii), mutual coupling(Sij), the peak gain, radiation pattern, radiation efficiency, Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Total Active Reflection Coefficient (TARC), Channel Capacity Loss (CCL) and Mean Effective Gain(MEG). The proposed 3D antenna performance analyzed when mounted inside the different types of housing. Hence, the proposed polarization diversity antenna is suitable for vehicular communication applications.

Design of compact dual-polarized multiband MIMO antenna using near-field for IoT

This paper presents the integration of the unlicensed ultra-wideband (UWB) with the existing bands like the 1.9 GHz long‐term‐evolution (LTE) band and 2.4 GHz industrial scientific and medical (ISM) band to cater for the diverse need of the upcoming internet of things (IoT) technology. The designed compact triband antenna has a dimension of 33 × 18 mm2 (i.e. 0.2λ0 × 0.11λ0, where λ0 is calculated at 1.89 GHz in the free space). This antenna provides high-quality factor (Q) and narrow-band impedance matching at the 1.9 and 2.4 GHz bands with about 2.9% and 4.7% bandwidth respectively, which is sufficient for those IoT applications, which are supposed to support low data rate communication. Further, the triband antenna is found to be effective for IoT as the hosting effect is within the tolerable range. Finally, multiband polarization diversity antenna is designed having a size of only 33 × 57.25 mm2 (0.2λ0 × 0.36λ0) to combat the depolarization effect of signals in the indoor environment. Near-field simulations are carried out to determine the best position/orientation of MIMO elements in order to improve port-to-port isolation and envelope-correlation-coefficient (ECC). The minimum isolation and maximum ECC are found to be 14.2 dB and 0.0471, respectively across all the operating frequency bands.

Wideband circularly‐polarised high‐gain diversity antenna loaded with metasurface reflector for small satellite applications

This Letter demonstrates the design of a two-element polarisation diversity antenna, applicable for modern small satellite application systems. The intended antenna mainly consists of two monopole radiators loaded with metasurface reflector as a ground plane. The dimensions of the radiator antenna are 40 × 22 × 1.6 mm 3 . The antenna measured results offers a wider S 11 bandwidth of (2.23-2.91 GHz) and wider axial ratio bandwidth (ARBW) of (2.16-2.92 GHz) with a common S 11 and ARBW of 26.45% is obtained. A maximum gain of 7.02 dBic and isolation better than 14.5 dB is observed along with the operating frequency range. The antenna provides an ARBW( 2.38 dBic) for theta = ± 45°, for all phi values along with the complete operating frequency range. Also, the antenna port-1 provides left-handed circular polarisation and port-2 provides right-handed circular polarisation radiation with directional radiation characteristics.

Dual CP Polarization Diversity and Space Diversity Antennas Enabled by a Compact T-Shaped Feed Structure

A compact T-shaped feed structure (TFS) is reported that enables the realization of two types of diversity antennas: a polarization diversity antenna (PDA) and a spatial diversity antenna (SDA). Both systems have a high potential for mobile wireless communication applications. The TFS includes four ports and two independent coaxial channels with effective isolation between them all. The PDA is a dual CP omnidirectional antenna. Its optimized prototype achieves measured impedance bandwidths of 16.4% and 15.28% in its LHCP and RHCP states, respectively, and realized gains in both between 4.8 and 6.46 dBic. The inner thin coaxial cable (ITCC) of the TFS directly drives its LHCP subsystem, facilitating its improved omnidirectional performance. This ITCC is also used to directly feed the SDA’s low-profile directional planar equiangular spiral antenna and its side port drives its omnidirectional RHCP antenna. Good hemispherical coverage is realized with a measured common impedance bandwidth larger than 14.35% with more than 40-dB isolation between its two ports. The corresponding measured realized gain of the SDA is between 4 and 7.8 dBic. The measured results for both optimized prototypes confirm their simulated performance characteristics.

Design and Measurement of 3D Flexible Antenna Diversity for Ambient RF Energy Scavenging in Indoor Scenarios

Ambient radiofrequency (RF) energy scavenging has been recently addressed with a wide range of studies to provide alternative powering for low-power applications. However, due to the low power level of the ambient electromagnetic field, the efficiency of the latter systems is still below expectations. Multipath in the environment may be considered and antenna diversity is then a solution for quasi-omnidirectional RF reception to reach a higher probability of receiving energy in a realistic situation. A 3D flexible antenna diversity, which can be integrated into the rectangular packaging, is proposed in order to take advantage of system packaging form. The angle and polarization diversity antenna was designed on flexible substrate in order to achieve the flexibility and low-cost. This design overcomes the low performance of the substrate while maintaining a compact, high isolation, and good radiation efficiency of the antenna. An indoor experimental setup was carried out to compare different rectenna configurations. The measurement results validate the principle and demonstrate the performance of the 3D flexible diversity system. The probability measurements were carried out under precise conditions in indoor scenarios and the results in comparison with statistic models confirmed the performance of the system in such low power conditions.

The Circular Polarization Diversity Antennas Achieved by a Fractal Defected Ground Structure

This paper proposes the circularly polarized (CP) antennas with a restored radiation pattern for the polarization diversity applications. The proposed CP antennas have dual polarizations, the left-handed circularly polarized (LHCP) antenna is designed for transmitting and the right-handed circularly polarized (RHCP) antenna is designed for receiving. The CP antenna operation and the radiation pattern restoration are realized by a fractal defected ground structure (FDGS). When achieving the radiation pattern restoration, the proposed CP antennas forward efficiencies are improved from 66.8% to 81% and the forward realized gains are improved from 2.56 dBi to 5.38 dBic, respectively.

A Design of Dual-Wideband Planar Printed Antenna for Circular Polarization Diversity by Combining Slot and Monopole Modes

A novel dual-wideband antenna is designed for circular polarization (CP) diversity in this communication. It consists of a horseshoe-shaped slot, two $L$ -shaped radiators, and two ports. The working principle of the horseshoe-shaped slot is half-wavelength slot mode, and the working principle of the $L$ -shaped radiator is quarter-wavelength monopole mode. The slot mode is applied to produce two lower CP resonant frequencies of two bands and the monopole mode are used to generate two upper CP resonant frequencies of two bands. By narrowing these two modes of two bands, a dual-wideband CP antenna can be designed easily. When port 1 is excited and port 2 is matched, this antenna radiates left-hand CP wave at lower band and right-hand CP wave at upper band at the $+ \textit {z}$ -direction. When exchanging the excited and matched ports, the radiation is reversed. The measured impedance bandwidths ( $S_{11} dB) are 113% (0.7–2.52 GHz) and 60.2% (3.47–6.46 GHz). The measured 3 dB axial ratio bandwidths are 72.5% (1.17–2.5 GHz) and 56% (3.52–6.26 GHz). The isolation between the two ports is better than 15 dB.

An Integrated Tri-Band/UWB Polarization Diversity Antenna for Vehicular Networks

The design, fabrication, and testing of an integrated polarization diversity antenna array for maximizing the wireless channel link in vehicular networks are presented in this paper. The diversity antenna is constructed using unit cell radiators that provide two operating modes. The mode transition is achieved using a pair of PIN diodes. In one state, the antenna provides multiband operation centered at 2.4, 3.5, and 5.8 GHz. In the other state, the antenna covers the entire ultra-wideband (UWB) spectrum. The unit cell radiators are distributed in the horizontal and vertical plane to achieve polarization diversity. Apart from offering a polarization diversity antenna, the orientation of antennas offers a reliable link with the communication devices. The prototype antenna array is fabricated and tested for diversity performance. The performance metrics such as envelope correlation coefficient, diversity gain, and mean effective gain under isotropic, indoor, and outdoor conditions are evaluated and presented.

Indoor Channel Capacity Measurement of 2 x 2 MIMO Polarization Diversity Antenna

&lt;span&gt;This paper presents the channel capacity investigation and the polarization reconfigurable antenna analysis for MIMO system in an indoor scenario. A single and dual-port polarization reconfigurable antenna is used at the receiver end to study the effect of polarization diversity configurations towards the achievable performance of the channel capacity. The polarization reconfigurable antennas are developed through two techniques, which are slits perturbation for single-port and feeding network modification for dual-port. The benefits offered by the designed antennas are investigated when being used as a receiver in both line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. The results show the proposed antennas are suitable to be adopted and highly potential to improve the channel capacity of the MIMO systems.&lt;/span&gt;

Planar Triorthogonal Diversity Slot Antenna

This communication proposes an easily manufacturable multifunction multiport planar slot antenna with triorthogonal pattern diversity. Distinct radiation patterns are emitted via a common square radiative slot by exploiting three orthogonal modes. These slot modes consist of a magnetic current loop mode with an omnidirectional linearly polarized (OLP) radiation pattern, and two degenerated linear slot modes radiating broadside with orthogonal linear polarizations (LPs). The triorthogonal patterns are obtained in an overlapping frequency band, and the mutual coupling between the ports is minimized through a differential feeding arrangement. This new concept of multiport diversity slot antenna is validated experimentally at a frequency of 5.9 GHz, successfully demonstrating the operation modalities of OLP and LP radiation patterns. A minimum triorthogonal overlapping impedance bandwidth of 2.3% is measured with interport coupling below −35 dB. The proposed antenna could be used as a pattern and polarization diversity antenna, where additionally, a linear combination of the primary triorthogonal patterns can be exploited to further enhance flexibility in pattern generation.

Polarization Diversity on ESM Systems

Polarization diversity antenna arrays are applied to electronic support measures (ESM) systems since the 1980s. However, even today modern systems are conceived with the employment of the traditional and inconvenient spiral antennas and there are no studies that evidences most of the benefits of this technique applied to them. This paper aims at showing not only the advantages on polarization matching issues, but also the benefits in gain, in simpler truncation effect problems and in costs and time spent on design and production. After a brief approach strictly applied to ESM of the main features of spiral antennas and bow-tie antennas compounding a polarization diversity array, equations of the power available from the last were developed from the concept of effective length. The results demonstrate that the array could provide a power 8.7 dB higher than a modern spiral would to an ESM system when it receives vertical or horizontal linearly polarized waves, which multiplies by 2.7 the range of the system, besides also presenting a better performance in case of circularly polarized incident waves. This work has contributed to propose a replacement to the very common use of spiral antennas on the upcoming ESM system projects. This study is recommended for the areas of Electronic Warfare, Electromagnetic Devices and Applications and Ultra-Wideband Antennas.

A Novel UWB FSS-Based Polarization Diversity Antenna

This letter explores the design of a novel ultrawideband band (UWB) dual-polarized antenna with unidirectional radiation characteristics. The proposed antenna consists of a dual-polarized radiator mounted on a backing reflector constituted of a single-layer frequency selective surface (FSS) with a UWB stopband response. A design guide for the proposed FSS is described along with its operation mechanism that enables the proposed antenna to provide a high gain of an average of 9.5 dBi along with good radiation characteristics over the two polarizations. A measured −10-dB impedance band covering the entire UWB band with an isolation level of 20 dB is obtained for a low profile of λ /10. Owing to its features, the proposed antenna is attractive for integration with low-profile broadband printed circuits and UWB diversity communication systems.