Polarization Reconfigurable Antenna Research Articles

Single-substrate active metasurface for polarization reconfigurable omnidirectional antenna application

In this paper, a wideband polarization reconfigurable omnidirectional antenna (PROA) based on a single-substrate active metasurface is proposed. By controlling the states of the PIN diodes, the antenna can selectively radiate an omnidirectional linearly polarized wave and an omnidirectional circularly polarized wave. The reflection coefficient, axial ratio (AR), radiation pattern, and gain of the proposed antenna have been analyzed from the perspective of simulation and measurement. The measured results show that the PROA has a wide overlapped bandwidth from 2.87 to 3.67 GHz (relative bandwidth 24.46%). To the authors' best knowledge, this is the first reported wideband PROA based on a single-substrate reconfigurable polarization converter. This study not only offers a novel approach to design PROAs, but also greatly reduces the design complexity of the feed source compared with the traditional design method of PROAs.

DEFECTED GROUND SQUARE PATCH EDGE TRUNCATED POLARIZATION RECONFIGURABLE ANTENNA

In this paper, a polarization reconfigurable antenna is reported. The proposed antenna operates in linear and circular polarization. Linear polarization is obtained using a square patch antenna and circular polarization is realized by truncating the diagonal corners of the square patch. Wideband circular polarization is obtained using two triangular defects to the ground plane beneath the truncated edge. To implement polarization reconfigurability, two pin diodes are placed on the truncated edges. These pin diodes electronically transform the proposed structure into square or truncated square patches resulting in linear or circular polarizations respectively. The proposed antenna operates in the 4.75 to 3 GHz band with circular polarization and the 4.75 to 1 GHz band with linear polarization. The antenna exhibits a higher peak gain of 7.7 dBi due to a low-loss foam substrate with the main lobe at 0°. A prototype of the antenna is developed and tested.

Intelligent Frequency, Radiation Pattern and Polarization Reconfigurable Antenna for 5G Applications

Intelligent Frequency, Radiation Pattern and Polarization Reconfigurable Antenna for 5G Applications

A fully reconfigurable 1 × 4 power divider with power division reconfiguration and size reduction based on series coupled cascaded transmission lines

This work presents a 1X4 fully reconfigurable power divider with a wide range of power divisions and reduced size, designed for adaptive null forming and beam steering networks in RF front ends. The design is based on the impedance transformation of series-coupled cascaded transmission lines and a reconfigurable isolation network. The impedance of power-dividing arms is transformed by tuning the voltage-dependent equivalent capacitor, controlling insertion loss, and indirectly influencing the power division ratio. Four transmission states with sixteen different power levels are realized. This design approach is validated by fabricating a prototype with four output ports. The measured power division varies from 6.5 dB to 18 dB at the center frequency, and the return loss is greater than -32 dB. Output port isolation is greater than -30 dB, and the phase response at output ports only shows a difference of less than 2 degrees. The power at any output port can be reconfigured independently without affecting the system’s overall performance, achieved through a series-coupled transmission line, contributing to a reduction in size. A size reduction of 37 percent is attained in this design. The proposed power divider can provide a wide range of power levels at all output ports within a narrow band around the center frequency. Hence, the design is suitable for beam steering networks, pattern, and polarization reconfigurable antenna arrays. The design also has extension capability into N-way configurations.

CRLH‐TL‐loaded metamaterial antenna with frequency band and polarization reconfigurability

SummaryIn this communication, an asymmetric co‐planar waveguide (ACPW)–fed composite right–left‐handed transmission line (CRLH‐TL)–based frequency band and polarization reconfigurable antenna (RA) is presented. The reconfigurability is achieved by using a PIN diode. When the diode is in OFF state, meander line works as part of ground. Hence, the antenna is like a circular patch antenna working at 5.15 GHz. In the ON state, the antenna works as a CRLH‐TL‐based antenna with an additional lower band resonating at 2.45 GHz. The antenna also has circular polarization (CP) property. The lower 2.4 GHz band is covering for IEEE 802.11 b/g/n/ax/be applications, whereas the higher band is covering the WiFi bands of IEEE 802.11a/h/n/ac/ax/be applications with CP radiation (upper band). This antenna is effective in a scattering environment such as in urban areas and indoor communication.

A dual-band, beam steering and polarization reconfigurable 2-bit array antenna for satellite navigation/communication applications

A dual-band array antenna for satellite navigation/communication applications with beam steering and reconfigurable polarization functions is proposed in this paper based on four 2-bit antenna units. The 2-bit antenna unit works in the dual frequency range of 1.55–1.65 GHz (GPS L1, GLONASS L1, GSNS L1, Beidou-2 B1) and 2.0–2.2 GHz (Mobile Satellite Service, MSS, downlink), and its phase can be controlled by PIN diodes flexibly. Therefore, the proposed array antenna has dual-band and beam steering characteristics. Besides that, the polarization of the proposed array antenna can be changed by covering a metasurface and rotating it at different angles. The measured results indicate that the proposed array antenna can achieve linear polarization (LP), left-handed circular polarization (LHCP), and right-handed circular polarization (RHCP). The proposed array antenna can realize LP beam steering within 45° and CP beam steering within 30° at 1.6, 2.0, and 2.2 GHz.

A novel dual-sense polarization reconfigurable dual-band microstrip antenna

In this paper, a novel dual-band, dual-sense, polarization reconfigurable dual coupled line square microstrip patch antenna is proposed. It comprises of a diagonal edge truncated square microstrip patch with a dual coupled line structure. The dual-band operation is realized by using dual coupled lines. They also aid in generating dual-sense of circular polarization (CP) at two resonances. The diagonal edge truncated square patch consists of four PIN diodes along with the bias circuit. It realizes a dual-sense of polarization reconfiguration like right-handed circular polarization (RHCP)/left-handed circular polarization (LHCP), linear polarization (LP)/LHCP, RHCP/LP at lower resonance f1 = 2.4 GHz and higher resonance f2 = 2.6 GHz respectively for different states of the diodes. The proposed antenna is designed, simulated, fabricated, and experimentally tested for validation. The experimental results of −10 dB reflection coefficient, 3 dB axial ratio for CP, gain, and radiation pattern characteristics at the two bands are acceptable and are found to be in concurrence with simulation results in all the states. The proposed antenna would be useful for multifunctional wireless communication applications.

A simple design and fabrication of polarization reconfigurable antenna for industrial scientific and medical-band applications

<span lang="EN-US">This paper proposes a simple microstrip patch antenna (MPA) that can reconfigure its polarization states from linear to circular polarization in real-time by means of a PIN diode. An antenna is fed by a 50 Ω coaxial cable through the substrate of Teflon with relative permittivity of 2.15. The proposed antenna possesses a simple patch with a one-sided corner truncated to achieve polarization reconfigurability. A PIN diode is loaded to connect the main patch with a truncated corner and further maintain dual polarization states such as linear polarization (LP) and circular polarization (CP). Advanced design system (ADS) was used as a simulator to simulate the antenna, and a good understanding was obtained between simulated and measured results. Measured results showed a good agreement with simulated results at all working frequencies of interest. It shows minimum reflection coefficient gain with -10 dB scattering bandwidth 100 MHz for LP states and 170 MHz for CP states. It also shows an axial ratio of 1.56 dB for CP, and the cross-polarization level is also in a satisfying range.</span>

Electrical Reconfigurability in Modern 4G, 4G/5G and 5G Antennas: A Critical Review of Polarization and Frequency Reconfigurable Designs

This paper presents a critical review of modern 4G, 4G/5G, and 5G antennas, which employ PIN diodes and Varactors for polarization or frequency reconfiguration. For the reviewed 4G and 5G polarization reconfigurable antennas, a new parameter named spectrum utilization "AR/ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> B.W." is defined for the first time to predict the shared spectrum between the impedance bandwidth and the axial ratio bandwidth for circularly polarized antennas. The calculated spectrum utilization for many designs revealed that the majority of implementations failed to achieve full utilization of the available bandwidth. Besides, employing multiple PIN diodes is shown useful in improving the spectrum utilization and in supporting multiple polarization states. For the reviewed 4G, 4G/5G and 5G frequency reconfigurable antennas, the focus is mainly on comparing the available tuning range, fractional bandwidth and the Fractional Bandwidth Change (FBWC) upon tuning. The latter parameter, is defined and calculated in this work to measure the change in the FBW upon tuning. Utilizing multiple Varactors is shown promising in improving a 4G antenna’s fractional bandwidth, while combining Multiple PINs and Varactors in one design is found efficient in improving the FBWC and the tuning range in the 5G spectrum.

A Wideband Dual-cavity-backed Polarization Reconfigurable Antenna Based on Liquid Metal Switches

A Wideband Dual-cavity-backed Polarization Reconfigurable Antenna Based on Liquid Metal Switches

Design of an Anisotropic Reconfigurable Reflective Polarization Converter for Realizing Circular Polarization-Reconfigurable Antenna

A polarization-reconfigurable antenna is presented here with the help of an anisotropic reconfigurable reflective polarization converter (RRPC). Proposed design consists of a monopole antenna as a source and an electronically switchable polarizer. Depending on the conducting states of only eight PIN diodes, which are placed on the top surface of the polarizer, linearly polarized (LP) wave generated by the monopole can be converted into left-hand circularly polarized (LHCP), right-hand circularly polarized (RHCP), and LP wave. Proposed RRPC has a ground plane on the back side and it is positioned below the source antenna with an air gap of 0.13 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> where λ is calculated at the antenna's operating frequency of 3.5 GHz. Overall configuration of the antenna is compact with a dimension of (0.31×0.31×0.19) λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . As fewer active elements are used in the proposed design, complexity of the circuit for biasing and losses would be less. To the best of authors’ knowledge, it is first time reported work on active reflective polarizer, which not only has LP-to-CP polarization conversion ability but also it possesses electronic polarization switching ability in between LHCP, RHCP, and LP states.

An enhanced gain of frequency and polarization reconfigurable graphene antenna in terahertz regime

In this paper, a patch antenna with a unique shape and feeding at terahertz frequency is presented. The shape of the patch can change between three shapes of triangle, rectangle, circle and slotted patches by using the properties of graphene. In this way, by changing the shape of the patch, it is possible to simultaneously take advantage of the features of patches with different shapes in one antenna structure. In addition to the ability of changing the resonance frequency of the antenna in the range of 3.8 to 5.3 THz, the polarization is also changeable between linear and circular polarization, so, we have a frequency and polarization reconfigurable antenna. Besides, by using a metasurface and proximity coupled feed, the gain of the antenna has been improved and the maximum gain of 3.7 dBi has been achieved. The provided antenna having a suitable impedance bandwidth in all states, and the maximum bandwidth 28.5%, can be used for wideband applications.

An Unconventional Shape Memory Alloy Low-Power Ratchet for Reconfiguring the Polarization of a Moiré Pattern-Based Antenna

In this article, a novel polarization reconfigurable antenna based on the Moiré effect is proposed. The presented design exploits substantial changes in the overlapped Moiré patterns to minimize the needed actuation for antenna reconfiguration. The novel antenna design is based on stacking two circular FR4 substrates on top of a truncated edge rectangular patch antenna. The top layers of both the substrates are milled into horizontal stripes forming the Moiré patterns. One of these substrates is fixed with respect to the antenna, while the second one rotates with respect to the fixed substrate. Upon rotation, these stripes from the two substrates overlap in pattern, which shapes the antenna. As a result, the antenna design is capable of switching its polarization scheme between vertical, horizontal, and circular with left-hand orientation. In addition, the Moiré patterns can also enhance the directivity and gain of the proposed antenna. The reconfiguration’s mechanical actuation is achieved via a nontraditional ratchet mechanism that uses shape memory alloys (SMAs). This realized actuation system is fast, flexible in its positioning, has low energy expenditure, and minimizes interference with antenna operation. An antenna prototype is fabricated and tested where measured results match the simulated performance.

MIMO antenna array with the capability of dual polarization reconfiguration for 5G mm-wave communication

This communication presents a polarization reconfigurable antenna array (PRAA) with Multi-input Multi-output (MIMO) formation for 5th generation (5G) millimeter wave (mm-Wave) communications. At first a single corner curtailed diagonal slotted cylindrical patch is printed on Roger RT Duriod 5880 and the overall size of the single antenna is 12 × 12 × 0.787 mm3. The circular polarization (CP) is realized by adding the diagonal slot in the circular patch. The antenna design is extended into two elements antenna array which occupies 20 × 20 × 0.787 mm3 footprint. The collection is formed using a T-shaped power divider/combiner. Pin-diodes are integrated with the patches to switch the polarization state between LP (Linear polarization) and CP radiation. The edge-to-edge distance between antenna elements is 6 mm. The design covers the 25.2–29.4 GHz band, and the maximum peak gain is 11.5 dBi. Moreover, a two-port (2 × 2) MIMO design is formed to increase the channel capacity. To isolate the ports, a sin-like slot is engraved in the ground, defected ground structure (DGS) technique of mutual coupling reduction; it can easily be implemented and increases the design efficiency. The port isolation is well above 30 dB for the entire operating band. Moreover, the Mean Effective Gain (MEG), Diversity Gain (DG), and Envelope Correlation Coefficient (ECC) are investigated, which are key performance metrics of MIMO. A prototype of the realized MIMO antenna system is fabricated, and the simulated outcomes carried out by Computer Simulation Technology (CST) tools are validated by experimental findings.

A simple coplanar waveguide fed polarization reconfigurable antenna design

A coplanar waveguide (CPW) fed polarization reconfigurable antenna for WLAN 2.4 GHz operation is studied. To achieve reconfiguration between left-hand circular polarization (LHCP), right-hand circular polarization (RHCP), and linear polarization (LP) with broad CP and LP operating bandwidths, the technique of switching only two PIN diodes embedded between the CPW feeding line and an open square-ring radiating element is introduced. As the radio frequency (RF) and direct current (DC) signals must be fed from the same feeding line (input port), during the experiment, an additional Bias-Tee element is introduced to the input port for combining the two signals.

A Polarization Programmable Antenna Array

Reconfigurable antennas are becoming a major antenna technology for future wireless communications and sensing systems. It is known that, with a single linear polarization (LP) reconfigurable antenna element, a preferred polarization can be produced from a set of multiple polarization states, thus improving the quality of the communication link. This paper presents a new concept of a polarization programmable reconfigurable antenna array that consists of a number of polarization reconfigurable antenna elements with a finite number of possible polarization states. By employing a new optimization strategy and programming the polarization states of all the array elements, we demonstrate that it is possible to realize any desired LP in the vectorial array radiation pattern with accurate control of sidelobe and cross-polarization levels (XPLs), thereby achieving the desired polarization to perfectly match that of the required communications signal. Both numerical and experimental results are provided to prove the concept, and they agree well with each other.

A single-layered metasurface inspired broadband polarization reconfigurable printed monopole antenna for hybrid wireless applications

A single-layered metasurface-loaded high-gain & broadband polarization reconfigurable λo/4 printed monopole antenna is investigated in this article. The proposed antenna configuration comprises of Y-shaped radiating monopole over partial ground plane with the extended twin parasitic conducting strips (PCS), is loaded with a single-layered metasurface (MS) reflector. To attain circular polarization (CP) characteristics, a BAR 50-02 V PIN Diode from Infineon is used to short the partial ground plane and one of the twin parasitic conducting strips (PCS-L). By utilizing the grid-slotted sub patches on the rectangular reflecting surfaces of MS layer with a volumetric dimension of 2λo × 1.65λo × 0.02λo, is placed just below Y-shaped monopole radiator (PYMA) at a height of 0.33λo, in which broadened impedance (IBW) and 3-dB axial ratio bandwidth (ARBW) with the enhanced CP antenna gain are achieved. Finally, proposed prototype of 1.33λo × 0.9λo × 0.02λ o, where λo = 5 GHz is fabricated and measured. It offers an measured IBW of 48.45 % (3.57–5.85 GHz), ARBW of 25.96 % (4.19–5.44 GHz) and the CP antenna gain of >8.35 dBic with antenna efficiency of >75 % in the desired operating bands. From the above results, the performance of single-layered metasurface-inspired polarization reconfigurable antenna confirms its suitability for hybrid wireless applications and also, it can be extended towards the scope of designing efficient RF energy harvesting system.

Pattern and polarization reconfigurable loop antenna with circular high‐impedance surface for 5G micro base station application

A novel type of loop antenna backed by four-element circular high-impedance surface (CHIS) for 5G micro base station application is presented. The CHIS is composed of four elements, each one in the shape of a truncated sector, and the complete CHIS acts as the reflection plane for the main radiating loop placed above. In all, the proposed antenna structure contains three variations, the size of which are all less than π × 322 × 7 mm3. By properly adjusting the distribution of excitations, the first antenna can steer its beam to all four quadrants with a tilted angle of θ = 15°, and the remaining two antennas are capable of changing its polarization state among arbitrary linear polarization, left-handed circular polarization and right-handed circular polarization. Particularly, the second four-port antenna can also achieve pattern reconfiguration by steering its beam tilting towards four different quadrants, covering the space of −30° ≤ θ ≤ 30° with realized gain over 7.19 dBi. To validate the proposed concept, three antenna prototypes operating at 3.5 GHz are designed, fabricated and measured. The measured results agree well with the simulated ones, proving that the proposed antenna can achieve the desired reconfiguration.

Design and characterization of polarization reconfigurable heart shape monopole antenna for 2.4 GHz application

&lt;span&gt;This article represented a heart shape reconfigurable monopole antenna with polarization diversity. The proposed antenna is fed by a 50 Ω microstrip feed line that is printed on a flexible FR-4 (εr=4.4) substrate. The antenna comprises a ring-slot, a cross slot and four positive-intrinsic-negative (PIN) diodes that are soldered on ring slot. Four PIN diodes act as a switch and by controlling these PIN diodes effective current direction is changed hence four various states of polarization are achieved. Four states of polarization such as horizontal linear polarization (H-LP), vertical linear polarization (V-LP), right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP) can be switched easily with the help of these PIN diodes and achieved an efficiency of more than 90%. Proposed antenna shows voltage standing wave ratio (VSWR)&amp;lt;2 at all working frequency and -10 dB reflection coefficients (RC) bandwidths (BW) (i.e., S11≤-10 dB) about 32.86% for linear polarization (LP) states while RHCP and LHCP states possess BW of about 31.61% and 31.67% respectively. It also shows axial ratio (AR) BW of 3.41% and 2.44% for RHCP and LHCP, respectively. Besides, the antenna has a well-suited omnidirectional pattern with a positive gain of all working frequency of interest where cross-polarization level is much lower than that of antenna gain.&lt;/span&gt;

On-Chip Polarization Reconfigurable Microstrip Patch Antennas Using Semiconductor Distributed Doped Areas (ScDDAs)

This paper presents two polarization reconfigurable patch antennas using semiconductor distributed doped areas (ScDDAs) as active components. One proposed antenna has a switching polarization between two linear ones, while the other one has a polarization able to commute from a linear to a circular one. The antennas are designed on a silicon substrate in order to have the ScDDAs integrated in the substrate, overcoming the needs of classical PIN diodes. Therefore, the proposed co-design method between the antenna and the ScDDAs permits us to optimize the global reconfigurable function, designing both parts in the same process flow. Both demonstrators have a resonant frequency of around 5 GHz. The simulated results fit well with the measured ones.