Hongyu Shi

Dual-band polarization angle independent 90° polarization rotator using twisted electric-field-coupled resonators

A bilayered chiral metamaterial is proposed to realize a dual band polarization angle insensitive 90° polarization rotator. The unit cell of the chiral metamaterial is composed by twisted electric field coupled resonators in four-fold rotation symmetry. The simulation and measured results show that this device can work in dual band with an extremely low loss and polarization conversion ratio of more than 99%. The study of the current and electric fields distribution indicates that the cross-polarization transmission is due to both the electric coupling and the magnetic coupling.

Gradient Metasurface With Both Polarization-Controlled Directional Surface Wave Coupling and Anomalous Reflection

A gradient metasurface is proposed to obtain both surface wave coupling and anomalous reflection. The unit cell of the gradient metasurface is composed by six electric field coupled resonators in different rotation angle, which provides a phase gradient. The simulation and measured results show that this gradient metasurface can work at 7.8 GHz as a surface wave coupler and at 10.288 GHz providing a phenomenon of anomalous reflection. At the two frequencies, the direction of the reflection is polarization-controlled, and the efficiencies are polarization-invariant. At left-handed polarization incidence, the direction of the coupled surface wave and the anomalous reflection are opposite to the situation at right-handed polarization incidence.

Broadband cross polarization converter using plasmon hybridizations in a ring/disk cavity

In this paper, we report on the design, fabrication and subsequent investigation of a broad band cross polarization converter based on a C2-symmetric ring/disk cavity. Different plasmon hybridization modes are excited in the ring/disk cavity and enable the polarization manipulations. The designed cross polarization converter can convert the x or y polarized incident wave to its cross polarized wave in the frequency range from 9.65 to 14.16 GHz with a bandwidth of ~38% of the central wavelength and an efficiency higher than 80%. At 9.25 GHz and 14.35 GHz, the x (y) polarized incident wave is converted to a left (right) handed and right (left) handed circularly polarized wave, respectively.

Quad-Band Probe-Fed Stacked Annular Patch Antenna for GNSS Applications

A novel probe-fed stacked annular patch antenna is proposed for Global Navigation Satellite System (GNSS) applications. The antenna has been designed to operate at the satellite navigation frequency bands including GPS, GLONASS, BDS-1, and BDS-2. In the design, four annular patches are stacked to achieve multiband operation and compactness. Quadrature phase feed network comprising four 90° stripline baluns is employed to ensure circularly polarized (CP) radiation. Another key feature of our design is the stepped-radius shorting pillar to reduce the well-known inductance due to longer feeding probes. The final antenna exhibits good impedance matching, broad pattern coverage, and pure CP performance at all designed bands. Details of design considerations and experimental results are presented and discussed.

A Reconfigurable Polarization Converter Using Active Metasurface and Its Application in Horn Antenna

This paper proposes a reconfigurable polarization converter based on a p-i-n diode controlled active metasurface (AMS). The AMS consists of a thin dielectric substrate and is tuned by two identical layers of elliptic split rings loaded with p-i-n diodes. The p-i-n diodes are positioned between the split gaps and biased through the interconnected elliptic split rings without extra bias network. The active design achieves conversion from linear to circular polarization when the p-i-n diodes are OFF, whereas no conversion takes place when the diodes are ON. A prototype of the proposed design is fabricated, and the operational characteristics are measured. Both the simulated and the experimental results verify the viability of the design. Subsequently, the converter is applied to a linearly polarized horn antenna as a superstrate, making the polarization of the antenna reconfigurable.

Ultra-broadband and high-efficiency polarization conversion metasurface with multiple plasmon resonance modes*

In this paper, we present a novel metasurface design that achieves a high-efficiency ultra-broadband cross polarization conversion. The metasurface is composed of an array of unit resonators, each of which combines an H-shaped structure and two rectangular metallic patches. Different plasmon resonance modes are excited in unit resonators and allow the polarization states to be manipulated. The bandwidth of the cross polarization converter is 82% of the central frequency, covering the range from 15.7 GHz to 37.5 GHz. The conversion efficiency of the innovative new design is higher than 90%. At 14.43 GHz and 40.95 GHz, the linearly polarized incident wave is converted into a circularly polarized wave.

Design of a Circular Polarized Horn Antenna with an Anisotropic Metamaterial Slab

Abstract In this paper, a novel design of a circular polarized horn antenna is presented. An anisotropic metamaterial slab with metal periodic structures printed on a substrate is designed and its constitutive parameters and S parameters are analyzed. It shows that the metamaterial is anisotropic and can turn a linearly polarized wave to a circular polarized one. Then a novel horn antenna composed of a conventional rectangular horn antenna and the metamaterial slab is fabricated and measured. The results show that the novel horn antenna radiates a left handed circular polarized wave with an axis ratio below 3 dB at 16 GHz, and its gain and radiation pattern are the same as those of the conventional rectangular horn antenna.

Stopband Frequency Selective Surface With Ultra-Large Angle of Incidence

In this letter, a stopband frequency selective surface (FSS) with great incident angle independence and polarization stability is proposed and fabricated. Each element of the FSS consists of a cross spiral patch and four same second iteration of H-shaped fractal parts in C4 rotation symmetry. This FSS exhibits great stability with the incident angle ranging from 0° to 80° for both TE and TM polarizations. In addition, patch dimension of the FSS element can tune the resonant frequency. However it has a negligible influence on incident angle independence and polarization stability. This means the proposed FSS can be applied in different frequency ranges and has potential values in practical applications. Both simulation and measurement of this FSS demonstrate stable transmission characteristics under different incident angles and polarizations and show satisfactory consistence.

Design of a 4-element Antenna Array for BDS Anti-jamming Applications

Abstract In this paper, a compact 4-element antenna array with the dimension of 150 mm × 150 mm is proposed for BeiDou navigation satellite system (BDS) anti-jamming applications. The proposed antenna array comprises of four identical microstrip right-handed circularly polarized (RHCP) antenna elements. The four microstrip antenna elements are placed in the same polarity with a distance of 80 mm between adjacent elements. The antenna element which employs dual probe-fed structure has a relatively small volume of 45 mm × 45 mm × 5 mm. The antenna array has been fabricated and measured. The experimental results show that the proposed antenna array is quite suitable for BDS anti-jamming application.

A multi-band spoof surface plasmon polariton coupling metasurface based on dispersion engineering

We propose a metasurface to achieve multi-band helicity dependent directional spoof surface plasmon polaritons (SPPs) coupling for circular polarized light in the microwave range. Our work shows that the coupling frequencies of spoof SPPs on the gradient metasurface are related to the dispersion relations of the metasurface, which indicate the desired coupling frequency can be manipulated by dispersion engineering. The proposed metasurface has counter-directional phase gradients for different helicity incidents and possesses multiple different dispersion relations by carefully designing the geometric parameters of each unit, which leads to the multi-band helicity-controlled directional spoof SPPs coupling. Both the simulation and experiment show that the multi-band helicity-controlled directional spoof SPPs coupling is achieved with a high efficiency.