As interferences are introduced from a main-lobe direction, which results in target signals being masked by interference, traditional adaptive beamforming and eigen-subspace projection methods cannot suppress effectively. A novel interference suppression method is proposed that processes the sample data using scanning property of single polarized antenna. The orthogonal polarization decomposition estimation receiving signal based on spatial characteristics antenna realized so diminished....

This paper presents a Luneburg lens and reflector along with the corresponding compact cost-effective multibeam antennas in Ka-band. The is composed of an air-filled parallel plate waveguide (PPW) loaded equal-sized metallic posts. upper PPW designed to curved surface meet requirement equivalent refractive index profile, meanwhile providing transition between feed waveguide. Also, based on law reflection, reflecting wall introduced achieve lens. By employing WR28 rectangular waveguides as...

Antipodal curvedly tapered slot antennas (ACTSAs) with different profiles are investigated to achieve the optimum circular polarization performance. The of slots can be determined by curves, such as linear, exponential, and logarithmic curves. Therefore, corresponding waveguide-fed circularly polarized (CP) antipodal exponential-logarithmic (AL-, E-, EL-TSA) designed, fabricated, measured at Ka-band for a comprehensive study. optimized AELTSA provides good impedance matching, gain above 10.3...

A wideband high-gain terahertz dielectric reflectarray working at 220 GHz is investigated both theoretically and experimentally. The unit cell consists of a ground plane block. reflection phase obtained by adjusting the height Using computational algorithm, composed 40 × cells designed fabricated through three-dimensional (3-D) printed technology. Four types 3-D material are measured using THz time-domain spectroscopy system. It found that maximum gain bandwidth proposed 31.3 dBi 20.9%,...

This letter presents an experimental realization of a subterahertz metallic gradient index (GRIN) lens multibeam antenna operating at 355 GHz. The is composed surface-wave Luneburg based on bed nails and feeder array nine WR-2.2 waveguides. the feeding structures are fabricated by same high-precision 3D printing technique metalized using magnetron-sputtering gold coating. has been measured, showing good reflection coefficients below −12.5 dB all ports multiple independent beams covering...

Abstract The Airy beam has attracted considerable interests due to its remarkable non‐diffracting, self‐bending, and self‐healing properties. An auto‐focusing (AFA) can be achieved by constructing two counter‐propagation beams, which is a novel method generate focusing effect. Traditionally, because of the complexity generation mechanism, it hard realize with complex amplitude modulation. reported ones usually require bulky optical systems typically work at one single wavelength. Here,...

This communication proposes a novel fully metallic multibeam Luneburg lens antenna that can simultaneously support the radiation of horizontal polarization (H-pol) and vertical (V-pol). The proposed consists parallel plate waveguide with varying spacing series loaded nails graded heights. Seven OMTs are employed as feeder. measured results show H-pol/V-pol peak gain is higher than 10.9 dBi/13.8 dBi from 28 GHz to 32 GHz. dual-polarized beam scan loss lower 1.1 dB −48° +48°. its potential for...

A phased array antenna (PAA) with wide beam scanning range (BSR) composed of fully metallic lens subarrays is proposed. Each subarray designed based on a partial Maxwell fish-eye (PMFE) lens, which provides linear quasi-focal line and wide-angle scanning, achieved by the combination passive switching phase shifting control. The PMFE lenses are realized parallel plate waveguides (PPWs) loaded nonuniform nails. To meet requirement spacing, miniaturization element staggering arrangement...

A terahertz (THz) waveguide-fed circularly polarized double-fan-shaped slot antenna (DFSSA) based on a silicon micromachining technology is proposed. The fed by WR1.9 waveguide. Optimized rotation angle of the can realize left-hand circular polarization or right-hand polarization. measured axial ratios are lower than 1.5 dB from 490 to 500 GHz. proposed DFSSA suitable be used as feeders in THz imaging and detection systems.

This article presents a Ka-band fully metallic crossover-in-antenna based on an anisotropic lens. The is multifunction device simultaneously acting as waveguide crossover and multibeam antenna. lens performs like Maxwell fish-eye (MFE) Luneburg in different incident directions, supporting the transmission radiation, respectively. consists of parallel plate (PPW) with gradient spacing loaded periodic uniform cuboid posts, which can be treated array subwavelength unit cells equivalent...

This paper presents a novel two-dimensional (2-D) partial Maxwell fish-eye (PMFE) lens with the capability of wide-angle beam scanning inspired by Gutman and Eaton lens, which is obtained cutting part from 2-D (MFE) along straight line. In terms refractive index profile, MFE similar to near center edge, respectively. We demonstrate potential PMFE in based on its Gutman-like focusing Eaton-like rotating characteristics corresponding different feed points. As an example, fully metallic antenna...

We present a high efficiency terahertz (THz) 90°-bend electromagnetic crystal (EMXT) waveguide using Si-based microelectromechanical systems technology. The 2-D EMXT consists of periodical array square-shaped gold rods (13 × 13 cells) deposited on silicon substrate, and 200-nm layer is further sputter-coated the rod array. dimension each 48 241 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , total size 1756 ×787 . fabricated by...

An active multifunctional terahertz modulator based on plasmon-induced transparency (PIT) metasurface under the effect of external infrared light was investigated theoretically and experimentally. A distinct window, which resulted from near-field coupling between two resonators, could be observed in transmission spectra. Experimental results showed a phenomenon induced blue shift both resonator with increasing optical powers. When power tuned 0 mW to 400 mW, amplitude tunability at window...

We demonstrate a stable and finely tunable optoelectronic oscillator (OEO) based on stimulated Brillouin scattering. In the proposed scheme, optical carrier in OEO loop pump light is generated by single laser source, which guarantees frequency stability of output microwave signal from OEO. Frequency tuning achieved varying via an electro-optic shifter composed dual-parallel Mach-Zehnder modulator (DPMZM) electrical 90° hybrid. Through subtly low-frequency applied to DPMZM, high-frequency can...

This letter presents a multi-beam wide-angle scanning antenna based on the E-plane-focused partial Maxwell fish-eye (PMFE) lens operating in Ka-band. The gradient equivalent refractive index distribution of is realized by parallel plate waveguide (PPW) partially filled with dielectric material, which can support E-plane focus. fed series rectangular waveguides arranged along straight cut line to realize multiple beams. To improve impedance matching, wedges are loaded interface between...

We report on a polarization-insensitive optical modulator architecture comprised of silica/Si/hBN/graphene/hBN/ graphene/hBN/Si stack upon silica substrate to support transverse electric (TE) and magnetic (TM) polarizing modes with identical absorption. The absorption between TE TM is strict condition for realizing electro-absorption modulator. This in turn entails significant compromise polarization-sensitivity loss. horizontal arm active region waveguide mode while supported by vertical...

In this paper a conformal antipodal Vivaldi antenna array on cylindrical surface for ultra-wideband (UWB) applications is proposed. The mounted the of object. has good characteristics after optimization geometry parameters antenna. with four can be designed UWB several octaves, and circularly polarization. Results show that suitable choice polarization application curved surface.

Numerical modeling of multiorder cascaded fluoride glass Raman fiber laser (RFL) employing Bragg gratings (FBGs) is presented. Calculations were compared with the recently reported results, and good agreement was achieved. The model also used to optimize a fourth-order RFL pumped at 1.9 , which can generate mid-infrared emission up 3.36. influences launched pump power, length, output coupling, background loss, insertion loss FBG on performance investigated. length 53.1-85.5 m reflectivity...

ABSTRACT A terahertz (THz) low‐profile corrugated horn antenna is proposed. This consists of WR2.2 feeding waveguide, pyramidal horn, and four V‐grooves, integrated fabricated by silicon micromachining. The grooves significantly enhance the gain maintain low profile original antenna. measured results from 480 to 500 GHz show above 15.6 dB narrow beamwidths without sidelobe, agreeing well with simulated indicating potential be applied in compact array THz imaging detection systems. © 2015...