Kun Wang

A miniaturized dual-port phase mode antenna (PMA) based on radial SSPPs structure with continuous scanning pattern and two kinds of 1-D linear extended arrays of it are proposed. The proposed PMA is composed with a vertical PCB (0.28λ×0.27λ) printing the SSPPs scatterer and the feeding loop of two isolated ports and a metal ground. Two independent equivalent current vectors are excited on the aperture by the two ports and summed up to be a current with rotating direction, which is controlled by the phase difference between the ports. The rotating current triggers rotating pattern of the PMA and introduces the continuous phase mode scanning characteristic of it. The PMA is extended to wide range 2-D scanning and gain overlapping futures of two 1-D arrays with two directions of arraying based on the generalized principle of pattern multiplication. A beam scanning range -81°<θ _m m < 76° ( xoz ) of the gain overlaying array with the same scale is realized with a 3.3 dB scanning gain fluctuation. The suppression of first side lobe and other advantages introduced by the proposed PMA in generalized array are demonstrated.

A novel compact wideband load-bearing planar inverted-F fishbone antenna (PIFFA) element and a circularly polarized (CP) unit based on PIFFA are proposed. The main radiator of the PIFFA is a folded fishbone structure with dimensions of 0.14λ ₀ × 0.19λ ₀ × 0.15λ ₀ , which is excited by a monopole. It works in hybrid mode dominated by odd mode, which realizes directional radiation. The PIFFA has an available bandwidth of 1.29 - 2.46 GHz (62.4%), and gain ranging from 3.98-5.76 dBi. Four PIFFA elements are rotationally symmetric arranged around the center and construct the compact CP unit. The measured operating bandwidth of the CP unit is 1.18-1.91 GHz (47.2%) and the gain ranges from 6.2-8.6 dBi. It is noted that the CP unit can bear the load of 1000 kg/cm ² without clear performance deterioration. In addition, four CP units are extended to form a linear one-dimension array with broadside dual circular polarization beam scanning capability. The one-dimension array achieves CP scanning range of ± 61° at 1.25 GHz in experiment. These results demonstrate that antennas designed with a folded fishbone structure have excellent performance and practical value, making them suitable for a wide range of high-speed wireless communication systems.

The general model of a dual-port phased antenna with a reflector is investigated. And a novel dual-port monopole antenna with corrugated structure above a HIS with a size of 0.30λ×0.39λ×0.16λ is proposed. The antenna can work in single-port excitation mode with main lobe deflecting to ±39° and dual-port excitation mode with main lobe scanning from 0° to 55°. An eight-element array with 0.5λ spacing is constructed based on the proposed dual-port phased antenna which can scan in two modes too. It can achieve a wide-angle scanning up to ±82° with a measured gain range of 12.6-9.6 dBi in the single-port excitation mode. Moreover, in the dual-port excitation mode, the internal phase difference between the two ports in one element and the phase shift between adjacent elements both can influence the array scanning performance. By adjusting the internal phase difference, the array gain is improved in the whole scanning angle range especially at the large scanning angle. The array can scan to ±81° with a measured gain range of 13.9-10.7 dBi in the dual-port excitation mode. It can be predicted that the phased array with dual-port phased antenna has great potential on wide-angle scanning application.

A wideband circularly polarized periodic leaky-wave antenna (PLWA) using a novel unit-cell with X-shaped slot is proposed. The X-shaped slot is fed by a 50 Ω microstrip line with an X-shaped stub closely on top of it. Furthermore, an equivalent circuit of the proposed unit-cell is established and verified. Approaches are introduced to enhance the impedance and CP bandwidths, which utilize a complementary X-shaped stub and displace one arm of it from the middle to another layer. A 1 × 16 PLWA is constructed with good CP performance. The open-stopband (OSB) is suppressed by using trapezoidal arms of the slot and stub and the CP performance of diffracted field is improved by introducing a pair of extra grounds. A 16 × 16 planar PLWA is further constructed using the 1 × 16 PLWA. And it has an impedance bandwidth of 52.5% (4.5 GHz – 7.7 GHz) and a CP bandwidth of 34.6% (4.5 GHz – 6.38 GHz) in the experiment. The frequency scanning range is from -58° to 48°, while the CP coverage is from -58° to 13°. The proposed antenna features a wide band and wide coverage, which could be a good candidate for wireless and radar applications.

In this paper, a long-range underwater EM communication system is proposed based on ultra-compact ELF magneto-mechanical transmission antenna (UEMTA). The transmitter mainly includes waveform generator, variable frequency drive (VFD) and a three-phase induction motor. And the receiver consists of a 200-turn coil and signal analyzer. Based on the equivalent model of rotating magnetic dipole, the principles of the EM transmission underwater and across the interface of water and air are analyzed. ELF wave propagating under water in the adjacent area was stronger and decays slowly, which was certificated by the experiment and simulation. So, the long-range transmission underwater in ELF band with digital coding modulation based on the UEMTA is realized, and the longest distance can reach 210 m under water in the experiment. The transmission of ELF wave across water-air medium based on the system is also tested by the experiment too. The long-range transmission of digital coding modulation across the water air interface is realized with the longest distance about 210 m. The ELF transmission technology based on the UEMTA can greatly promote the flexible long-distance underwater transmission, the development of satellite-to-submarine communication and ocean exploration.

We demonstrate analytically the technique and arrangement of nanoparticle antenna arrays with the enhancement of optical characteristics at an optical frequency regime. The optical characteristics of the array are enhanced by introducing an inverse active spherical coated nanoparticle (I-CNP). This inverse active spherical coated nanoparticle is designed and combined with already demonstrated active CNPs. Consequently, three types of active CNPs and their inverse-based plasmonic nano-antenna array configurations have been designed and studied: two CNP configurations, two inverse CNP (I-CNP) configurations and a CNP with an I-CNP configuration in the presence of passive elements. Detailed near-field analysis contains an E-field, radiated power, scattering and absorption examination, whereas far-field analysis includes gain and pattern investigation. The finite-difference time-domain (FDTD) simulation results in CST depict the benefits of a CNP with an I-CNP array configuration in the presence of passive elements over the other two in terms of both near-field and far-field characteristics, at closer inter-element distances because of coupling avoidance with possession of a dipolar pattern.