A Polarization Reconfigurable Patch Antenna in the Millimeter-Waves Domain Using Optical Control of Phase Change Materials

Abstract

We present the integration of GeTe (Germanium Telluride), a phase change material (PCM), within the structure of an antenna operating in the millimeter wave domain (∼ 30 GHz) in order to make it reconfigurable in three polarizations: a linear polarization (LP), a left hand circular polarization (LHCP) and a right hand circular polarization (RHCP). The device is based on a conventional patch antenna excited by a microstrip line with the GeTe material integrated into the four corners of the patch. The phase change between the insulating (OFF) and metallic (ON) states of this material is controlled by direct irradiation using ultraviolet (UV) short laser pulses and allows the reconfigurability of the antenna between an LP, an LHCP and an RHCP. The measured performances of the fabricated device show axial ratios of less than 3 dB over a 400 MHz of bandwidth around 29.5 GHz with total efficiencies up to 75 % for the circularly polarized configurations and a maximum gain up to 8.3 dBi for the linear polarization states. INDEX TERMS Optical activation, patch antenna, phase change material, polarization reconfiguration.

A broadband circularly polarized monopole antenna for millimeter‐wave short range 5G wireless communication

“…The main features and performances of the proposed inverted‐L grounded stub loaded horizontal T‐shaped monopole antenna with other referenced different types of mm‐Wave CP antennas, as shown in Table 7. As per the author's knowledge, the proposed antenna featured simple geometry, broadband impedance and AR bandwidths along with dual sense polarization as compared to referenced diverse categories of complex geometries mm‐Wave CP antennas in References 21‐29 except gain in References 23‐28 considering mainly array and waveguide configurations. In References 21, 24, and 29 the size of the antenna is small but gain, impedance and AR bandwidths are also small as compared to proposed antenna except 24 .…”

“…The CP response can be tuned through changing the parameter of inverted‐L grounded stub and deformed T‐shaped patch. In addition, the major advantages of the proposed work in comparison of cited references 21‐29 are as follows: It is a simply structured and single layer antenna, which make it easy to fabricate and integrate into circuit board. It has the widest measured AR bandwidth of 13.67% and impedance bandwidth of 27.9% along with the dual sense polarization capability and flat gain response over operating bandwidth at mm‐Wave frequency range. …”

“…A SIW antenna array, 25 the FSS based structure, 26 the waveguide antenna, 27 the slotted SIW cavity antenna 28 and the patch antenna 29 are studied for CP response. Although, the main demerits of the reported diverse categories antenna structures in References 21‐29 are complex geometries, narrow impedance and AR bandwidths. So, the design of antenna having simple geometrical structure, broadband CP bandwidth and dual sense polarization is a vital research area in the present scenario to cover mm‐Wave 5G applications.…”

“…Alternatively, the SIW and frequency selective surface (FSS) techniques have been also considered to generate the CP. A SIW antenna array, 25 the FSS based structure, 26 the waveguide antenna, 27 the slotted SIW cavity antenna 28 and the patch antenna 29 are studied for CP response. Although, the main demerits of the reported diverse categories antenna structures in References 21-29 are complex geometries, narrow impedance and AR bandwidths.…”

Optical Reconfigurable Terahertz Devices using Phase Change Materials

“…The reconfiguration capability is based on the unique properties of PCMs undergoing a non-volatile phase transition on nanoseconds timescales from an amorphous (insulating) state to a crystalline (metallic), drastically changing their electrical and optical properties upon application of thermal, electrical or optical stimuli. [14][15][16][17] These PCM capabilities have been exploited over the years for realizing non-volatile memories by stacking the material between two electrodes and changing its state using pulsed current-Joule heating [18,19] . More recently, GeTe and GST compositions have shown their ability to be used as high performance, bi-stable switching devices in the microwaves/ millimeter waves domains, holding high-promises for future multi-reconfigurable telecommunication systems [20,21] .…”