A planar polarization-reconfigurable metasurfaced antenna (PRMS) designed using metasurface (MS) is proposed. The PRMS antenna consists of a planar MS placed atop of and in direct contact with a planar slot antenna, both having a circular shape with a diameter of 78 mm (0.9 $\lambda_{0}$ ), making it compact and low profile. By rotating the MS around the center with respect to the slot antenna, the PRMS antenna can be reconfigured to linear polarization, left-hand and right-hand circular polarizations. An equivalent circuit is used to explain the reconfigurability of the antenna. The PRMS antenna is studied and designed to operate at around 3.5 GHz using computer simulation. For verification of simulation results, the PRMS antenna is fabricated and measured. The antenna performance, in terms of polarization reconfigurability, axial-ratio bandwidth, impedance bandwidth, realized boresight gain and radiation pattern, is presented. Results show that the PRMS antenna in circular polarizations achieves an operating bandwidth of 3.3–3.7 GHz (i.e., fractional bandwidth 11.4%), a boresight gain of above 5 dBi and high-polarization isolation of larger than 15 dB. While the PRMS antenna in linear polarization achieves a gain of above 7.5 dBi with cross-polarization isolation larger than 50 dB.

Design of Polarization Reconfigurable Antenna Using Metasurface

A single-feed circular microstrip antenna with reconfigurable polarization capability is proposed. This antenna has a simple structure, which consists of a radiating circular patch, five switches (PIN diode), three matching stubs, and a 50 microstrip feed line. It can be switched between 4 different states: two states (low-frequency and high-frequency) for linear polarization (LP), one state for left hand circular polarization (LHCP) and one for right hand circular polarization (RHCP) by controlling the bias voltage of two PIN diodes. At the same time, three switchable matching stubs are used for matching every polarization state. Simulation results and experimental results show that the proposed antenna demonstrates a low cross polarization level, good impedance bandwidth, and a very good axial ratio in the circularly polarized states.

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A Novel Single-Feed Circular Microstrip Antenna With Reconfigurable Polarization Capability

A compact U-slot microstrip patch antenna with reconfigurable polarization is proposed for wireless local area network (WLAN) applications. PIN diodes are appropriately positioned to change the length of the U-slot arms, which alters the antenna's polarization state. Two antenna prototypes with identical dimensions are designed, fabricated and measured. The first antenna prototype enables switching between linear and circular polarization by using a PIN diode and a capacitor located on the U-slot. The second antenna prototype uses two PIN diodes to switch between the two circular polarization senses. A good impedance match (S11 ≤-10 dB) for both linear and circular polarization is achieved from 5.725 to 5.85 GHz, a band typically used for WLAN applications, and the 3 dB axial ratio bandwidth is greater than 2.8%. Details of the simulated and measured reflection coefficient, axial ratio, gain and radiation patterns are presented.

Polarization Reconfigurable U-Slot Patch Antenna

A millimeter-wave frequency scanning antenna, which is capable of dynamically changing the state of polarization thereby providing four modes of operation, is investigated and synthesized in the half mode substrate integrated waveguide (HMSIW) technology. This antenna is a planar passive circuit and fabricated by the low-cost PCB process. It is able to operate in either linear or circular polarization (LP or CP), depending on the requirements of its specific application. A wide angular region can be covered by 3 dB beam-widths of the continuous scanning LP beams and CP beams varying the frequency. It has good performance validated by measurements and has nearly a half reduction in size compared with the substrate integrated waveguide (SIW) version. The axial ratios of CP modes are excellent in the main beam directions within whole frequency band of interest and the isolations between each channel are good as well.

Millimeter-Wave Half Mode Substrate Integrated Waveguide Frequency Scanning Antenna With Quadri-Polarization

A single-fed reconfigurable microstrip antenna that can provide various polarization diversities is presented in this paper. The antenna is excited by a microstrip feed line through aperture coupling. When two PIN diodes are used to respectively reconfigure the coupling slot and the open stub of the feed line, the polarization of the microstrip antenna can be switched between vertical and horizontal polarizations. For the reconfigurable antenna with the linear polarization diversity, it can be converted to a circularly-polarized antenna with switchable polarization sense by introducing a perturbation segment. Moreover, an antenna with the quadri-polarization diversity, including dual orthogonal linear polarizations and two circular polarizations, is also developed from the structure of the switchable circular polarization microstrip antenna, and only three diodes are required. Details of the antenna design are shown, and the measured results for the constructed prototype are also exhibited and discussed.

Single-Fed Microstrip Patch Antenna With Switchable Polarization

A novel reconfigurable microstrip antenna with switchable polarization sense is proposed. The proposed antenna has a simple structure, consisting of a corner-truncated square radiating patch, four small triangular conductors, and a microstrip line feed. Using independently biased PIN diodes on the patch, it can produce linear polarization, or left- or right-hand circular polarization according to bias voltages. From the measured results, low cross-polarization levels when operated in the linear state and good axial ratios in the circular state are observed.

A reconfigurable microstrip antenna for switchable polarization

A switchable triangular microstrip antenna for dual-frequency operation is proposed. Two spur-lines are incorporated into the triangular patch, and two pin diodes are utilized to switch the spur-lines on or off. The resonant frequency of the microstrip antenna can be adjusted by setting the diodes on or off. Because the antenna structure is printed on a single metal layer, this antenna can be easily constructed.

T.U. Jang

Papers

A reconfigurable microstrip antenna for switchable polarization

Swithchable triangular microstrip patch antenna for dual-frequency operation