Polarization Reconfigurable Antenna Research Articles

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

<span>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)<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.</span>

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.

A Dipole with Reflector-Backed Active Metasurface for Linear-to-Circular Polarization Reconfigurability.

In recent years, significant advances have been made in diversifying the capabilities of communication systems by using reconfigurable antennas. There are many types of reconfigurable antennas—to achieve pattern, frequency, or polarization reconfigurability. These antennas are reconfigured either by the mechanical rotation of surfaces or by enabling or disabling specific sections of the structure using electrical switches. This paper focuses on the concept of a polarization reconfigurable antenna based on an active reflector-backed metasurface. An antenna system based on an active reflector-backed metasurface combined with a planar dipole is designed to achieve reconfigurable polarization. The polarization of the designed antenna can be switched between linear and circular polarization states using positive-intrinsic-negative diodes located in the unit cell elements of the metasurface. The measured results correlate well with the simulated results. The antenna has a physical size of 308 × 162 × 35 mm3 with an impedance bandwidth of 4.5% in the linear state and 7% in the circular state, as well as an axial ratio bandwidth larger than 8.3%.

An RHCP and LHCP polarization reconfigurable microstrip antenna for ISM band smart city applications

Abstract In this article, a microstrip antenna having circular polarization switching capability is presented. This antenna consists of a circular-shaped radiating patch with a single co-axial probe feed line. The polarization reconfigurability is achieved by introducing four symmetrical U-shaped slots and silicon PIN diodes on the radiating patch. A prototype of the design is fabricated on an FR-4 substrate with overall dimension of 70 × 70 × 1.6 mm to verify the performances. The measured results of the antenna exhibit an impedance bandwidth (S 11 < −10 dB) of 5% in the frequency range of 2.37–2.49 GHz. The maximum gain of the antenna is found to be 2.99 dBic at 2.43 GHz. The antenna shows stable radiation performances at 2.4 GHz with 4.1% of 3-dB axial ratio bandwidth, and more than 105° of 3-dB axial ratio beamwidth for both right-hand circular polarization and left -hand circular polarization which make it suitable for ISM band Smart city applications.

Bandwidth Enhancement and Size Reduction of a Low-Profile Polarization-Reconfigurable Antenna by Utilizing Multiple Resonances

A new design method to significantly expand the axial ratio (AR) bandwidth of a single-fed, low-profile circularly polarized (CP) antenna without relying on any complex feed network or occupying a large transverse dimension is presented. First, four small patches arranged in chessboard pattern are utilized as the main radiator, and meanwhile, a cross slot with unequal slot lengths is adopted to excite triple sequentially orthogonal modes, aiming to attain two CP modes (AR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> and AR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ). Second, in order to further considerably enhance the AR bandwidth and concurrently reduce the overall size, the feeding cross-slot resonance is favorably excited and effectively coupled by the chessboard patches to produce a new slotline-based CP mode (AR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) located before AR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> . Finally, an I-shaped top-loaded monopole fence, as a new degree of design freedom, is employed to collaboratively regulate these multiple resonances to form a wide AR bandwidth covering AR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> , AR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , and AR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> . Results show that, on the premise of keeping the inherent compact-size and low-profile advantages of microstrip antenna, the 3 dB AR bandwidth is remarkably enhanced up to 30.1% by the combination of the three CP modes. Based on the design method, a wideband polarization-reconfigurable antenna with switchable linear polarization (LP), left-handed circular polarization (LHCP), and right-handed circular polarization (RHCP) states is further designed and experimentally validated. The measured results demonstrate that, with quite compact transverse size ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.16\lambda _{0}^{2}$ </tex-math></inline-formula> ) and low profile ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.04\lambda _{0}$ </tex-math></inline-formula> ), a wide overlapped bandwidth (27.6%) of the polarization-reconfigurable antenna is successfully accomplished.

A mode‐combination‐based polarization‐reconfigurable antenna

In this article, a novel polarization-reconfigurable antenna based on the theory of linearly polarized (LP) modes combination is proposed. The antenna can electronically alter its polarization states between left-hand circular polarization, right-hand circular polarization and continuous linear polarization. A corner-truncated square patch with two isolated aperture-coupling feeds is used as the main radiator. By independently exciting the two feeding ports, the proposed antenna can work in two isolated orthogonal LP modes at 2.45 GHz, respectively. By simultaneously exciting the two feeding ports with different combination of amplitudes and phases, two circularly polarized (CP) modes and LP modes polarized at arbitrary azimuth can be obtained. The simulated and measured gains for all the polarization states are 7.3 dB at 2.5 GHz. The –10 dB impedance bandwidth ranging from 2.35 to 2.58 GHz is fully overlapped for all the polarization states.

Polarization Reconfigurable and Beam-Switchable Array Antenna Using Switchable Feed Network

A novel array antenna with reconfigurable polarizations and radiation pattern agility is presented in this paper. The digital-controllable array antenna has the functional capabilities of reconfigurable polarization and switching beam, which consists of cavity-backed antenna element based on substrate integrated waveguide (SIW) technique, parasitic patch array, power dividers and phase shifters. Polarization modes and radiation patterns can be dynamically controlled by means of Microcontroller Unit (MCU) with the different feeding ports and phase difference. To validate this proposal, the performance of the fabricated device was measured at the operating frequency of 5.4 GHz. Measured results indicate that the 10 dB impedance bandwidths and 3 dB axial ratio (AR) bandwidths cover from 5.25 to 5.6 GHz, and the measured gains range from 7.9 to 10.1 dBic. The experimentation and simulation verify that the proposed antenna can achieve two polarization states and five radiation beams of each polarization state, which indicate a good performance of the polarization reconfigurable and beam switching antenna array.

A scanning phased array based on a polarization reconfigurable antenna with compact aperture size

A compact antenna with tri-polarization switching is presented. The antenna is mainly composed of a monopole slot and a shorted loop, and the two radiating elements are connected in series and placed in a metallic box filled with dielectrics. To realize polarization switching, four PIN diodes are introduced into the antenna structure, and they cannot only suppress the excitation of the loop antenna but also vary the direction of the current flowing on the loop. Both simulated and measured results indicate that the proposed antenna can be operated in one linear polarization and dual circular polarization modes within an impedance bandwidth of around 15%; moreover, the aperture size of the antenna is about 0.09 λ02. Based on the polarization reconfigurable antenna, a 1 × 8 phased array with an aperture size of 0.3 λ0 × 2.8 λ0 is then developed. Simulated results show that the phased array operating in each polarization mode can give a gain fluctuation of smaller than 1.5 dB and a side lobe level of less than −10 dB when the beam is scanned from −60° to 60°. Experiments are also carried out, and their results have good agreements with the simulated data.

Quarter wavelength parasitic stub loaded polarization reconfigurable patch antenna

ABSTRACT In this paper, a microstrip single feed circular radiating patch loaded with two parasitic stubs to achieve diversity for antenna polarization is presented. The primary antenna is a circular metallic patch with a rectangular slotted Defected Ground Structure (DGS) and it resonated at 5.5 GHz for Linear Polarization (LP). To achieve Left and Right Hand Circular Polarization (LHCP and RHCP) two-quarter wavelength metallic stubs are attached with a radiating patch through two PIN diodes. The antenna reconfigures its polarization states between LP, LHCP, and RHCP by diodes switching configurations. The proposed antenna is printed on a 0.8 mm thick RT/Duroid 5880 substrate and it provided satisfactory agreement between measured and simulated results. It has an impedance bandwidth of 5.23–5.75 GHz (9.45%) for S11 less than −10 dB and Axial Ratio Bandwidth (ARBW) for 3 dB is approximately 5.4%.

An artificial magnetic conductor loaded, polarization reconfigurable circular patch array antenna

A low-profile polarization reconfigurable circular patch array antenna is presented in this article. It is illustrated that by introducing two reverse arrangement diodes in every concentric ring patch, the direction of current on the surface of the antenna can be switched flexibly, by controlling the operating states of the diodes. Thus, the polarization of the proposed array antenna can be switched in either left hand circularly polarization or right hand circularly polarization. The introductions of artificial magnetic conductor decrease the profile of the proposed antenna. The performances of the proposed antenna were validated by the prototype processing. The measurement results show that the proposed antenna has a 16.3% impedance bandwidth and a 6% 3 dB axial ratio bandwidth. It exhibits a 9.5 dB broadside gain in the CP band. The profile of the proposed antenna is 46.9% lower than the previous design. The measured results are in good agreement with the simulation results. And it has potential applications in S-band satellite communications.

Polarization Re-Configurable Antenna with Increase Gain for Small Satellites

Future small satellites require the development of reconfigurable antennas. Designing such antennas, especially single port patch antennas with circular polarization is a challenging task. Therefore, we propose both right-hand/left-hand circularly polarized (RHCP/LHCP) antenna which can reconfigure. The proposed antenna follows patch topology with E-shape that is single-layer and single-feed with two RF switches. The switches can alter the polarization in real-time. We also show various properties of the proposed antenna, such as radiation pattern, impedance matching, axial ratio, and bandwidth through simulations and measurements. The proposed model shows excellent performance and agrees well with the measurements. The performance of the antenna shows an effective bandwidth of 2.45 GHz–2.82 GHz with a maximum gain of 9.88 dB at 2.55 GHz. The symmetry of the antenna radiation is preserved by switching between the LHCP and RHCP polarization modes.

High gain polarization reconfigurable antenna arrays using a polarization reconfigurable converter

In this article, designs of high gain polarization reconfigurable antenna arrays are proposed. A reconfigurable single-layer polarization converter working in transmission mode is integrated with 1 × 4 and 2 × 2 patch array antennas to arrive at the design of polarization reconfigurable antennas. The antenna arrays with the polarization converter radiate linearly or circularly polarized waves depending on the bias state of PIN diodes used in the converter. LP wave is obtained if the diodes are forward biased while the reverse bias state of the diodes provides a circularly polarized wave. The 1 × 4 patch array integrated with the polarization converter exhibits an operating bandwidth of 6.12% (14.5-15.4 GHz) with an average gain of 14.3 dB for the linear/circular polarization states. The operating bandwidth of 6.75% (14.3-15.3 GHz) and an average gain of 12.6 dB are obtained for the 2 × 2 patch array with the converter. The prototypes of the antenna arrays with the polarization converter are fabricated and their performance characteristics are measured. The simulated and measured results are found to be in close agreement.

A simple semi-circular arc shaped frequency and polarization reconfigurable antenna

A simple semi-circular shaped antenna having frequency as well as polarization reconfigurability is presented in this work. The proposed antenna has a size of 70.4 × 67.5 × 1.52 mm3. This antenna consists of three switches (S1, S2 and S3) which have been used to attain frequency reconfigurability and polarization reconfigurability in both LP (linear polarization) and CP (circular polarization). When switch S1 is OFF and any of switch S2/S3 is ON then we are obtaining frequency at Single Band (2.4 GHz). When Switch S1 is ON and any of the Switch S2/S3 is OFF then we are obtaining frequency at dual Band (2.4 GHz and 5.52 GHz). When all the switches S1, S2 and S3 are ON at the same time then we are obtaining frequency at Single Band (5.52 GHz). The simulated fractional bandwidth of the lower band centred at 2.4 GHz is observed to be 17.4% and for the upper band centred at 5.52 GHz is observed to be 5%. Proposed antenna gain greater than 2dBi is obtained for all five cases along with less than 2 VSWR with excellent radiation efficiency. The proposed reconfigurable antenna is suitable for Bluetooth and WLAN application.

Metamaterial‐based, miniaturised circularly polarised antennas for RFID application

Miniaturised circularly polarised (CP) antennas based on dispersion-engineered metamaterial transmission lines (TLs) are proposed and developed for RFID applications. It is first studied and developed based on the equivalent circuit and dispersion curves of composite right/left-handed TL (CRLH-TL), which is featured by a novel/low-cost double-layered 3D structure, including metallic screws, one ground layer and metal-insulator-metal (MIM) capacitor loaded on the top layer. CP radiation is achieved by two crossed CRLH-TLs with a microstrip-slot coupling excitation. One CP antenna and one polarisation reconfigurable antenna, which utilise CRLH-TLs are then implemented, respectively. Compared with the conventional right-handed (RH) TL-based antennas (positive resonance-based antennas), miniaturisation is achieved by pushing down the dispersion curve to a lower frequency using larger LH capacitance or/and inductance. Negative-order resonances could be successfully excited by cascading π-type unit-cells. It shows similar radiation characteristics and additional size reduction as the positive resonance-based antennas. This antenna shows an electrical size of 0.24 λ0 × 0.24 λ0 × 0.03 λ0, a −10 dB bandwidth of 4.8%, and a peak gain of 4.2 dBic. It demonstrates advantages in terms of flexible size reduction, low cost, easy manufacturing, and good radiation performance, which are very suitable for 902–928 MHz UHF band RFID application.

A Switchable Polarization Slotted WLAN Antenna with DGS for IOT and Medical Applications

This work a 20 X 35 X 0.8 mm3 rectangular polarization reconfigurable antenna with four slots made at the corners of the patch. These four slots give the appropriate extra modes for circular polarization. Switching between LP and CP can be achieved using a PIN diode which is inserted across an L-shaped slit in the plane of the ground. The designed antenna is optimized and analyzed through simulations. The axial ratio (< 3 dB) bandwidth and impedance bandwidth (< -10 dB) are overlapped from 5.15 to 6.25 GHz (19.3%). The prototype antenna is tested for both states of the diode (forward and reverse bias). The working band covers the wireless local area network (IEEE 802.11a) band (5150 – 5350 MHz, 5725 – 5825 MHz) and HIPERLAN band (5450 – 5725 MHz) and a favorable compromise between simulated and tested outcomes. The omnidirectional radiation diagrams of the antenna are suitable for wireless portable medical devices.