In Geosynchronous SAR (GEO SAR), because of the increase orbit height, signal propagation delay time reaches up to hundreds milliseconds, and synthetic aperture also seconds which will result in a curved trajectory, thus "Stop-and-Go" assumption conventional imaging methods low earth (LEO SAR) lose effect GEO SAR. addition, angular velocity rotation is approximately equal that satellite rotation, Doppler parameter resolution analysis LEO cannot be directly used too either. this paper,...

Geosynchronous (GEO) SAR has been proposed as a means for obtaining observations of the Earth with finer temporal sampling than possible single satellite from lower orbit. However, standard algorithms developed low-Earth-orbit imaging are inadequate GEO, where typical assumptions quasi-linear trajectory and "stop-and-go" transmit/receive propagation break down because long integration time very range between Earth. This paper proposes curved model to overcome these limitations considers...

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...

Detecting the vertical profile of optical properties is an important task in remote sensing upper ocean, especially for 3-D reconstruction. Ocean color can only provide surface information, while light detection and ranging (lidar) technique depth-resolved data. Lidar global-scale observations ocean days nights with minimal atmospheric correction errors. Unfortunately, due to strong multiple scattering effects that occur when propagates seawater, simple lidar equation may cause some...

This paper demonstrates further research on intelligent algorithms of binary amplitude optimization for wavefront shaping by numerical simulations. A better fitness function the genetic algorithm (GA) has been presented after a comparative analysis enhancement. With this new discriminant, we have achieved relative enhancement 0.225, which is higher than theoretical value (0.159). In addition, also proposed kind modified particle swarm (PSO), unmodified PSO and faster convergence speed GA....

A novel dual-polarized 2D beam-steering antenna is proposed based on the reconfigurable double square loops (RDSLs). The composed of stacked patches with two ports and a surface consisting 2 × array RDSLs. Varactor diodes are integrated inner loop RDSL. steerable radiation beam can be continuously controlled by tuning four biasing voltages applied for both polarizations. experimental results show that scanning ranges up to ±32° in principal planes. has an average gain 7.87 dBi fluctuation...

Multiple scattering is an inevitable effect in spaceborne oceanic lidar because of the large footprint size and high optical density seawater. The effective attenuation coefficient klidar equation, which indicates influence multiple on formation returns, important parameter retrieval inherent properties (IOPs) In this paper, relationships between signal IOPs seawater are investigated by solving radiative transfer equation with improved semianalytic Monte Carlo model. Apart from geometric...

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...

A compact fully metallic millimeter-wave (MMW) periodic leaky-wave antenna (LWA) based on corrugated parallel-plate waveguides with high radiation efficiency and low machining complexity is presented in this letter. The LWA consists of a smooth plate that integrates the corrugation for slow-wave transmission line radiating slots. By introducing two different elements into one unit, open stopband effect improved broadside scanning realized. As an experimental verification, prototype Ka-band...

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 semianalytic Monte Carlo model is developed to simulate oceanic high-spectral-resolution lidar (HSRL) signals with multiple scattering. The phase function effects on HSRL retrieval are studied, e.g., the effective particulate 180° volume scattering (VSF) and attenuation coefficient that describe characteristics of backscatter attenuation, respectively. results demonstrate backward forward functions both have a significant influence δ1, which relative difference between true VSF. values...

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...

In this paper, we have experimentally demonstrated light focusing through strongly scattering media by performing binary amplitude optimization with a genetic algorithm. the experiments, control 160 000 mirrors of digital micromirror device to modulate and optimize transmission paths in media. We replace universal target-position-intensity (TPI) discriminant signal-to-background ratio (SBR) With 400 incident segments, relative enhancement value 17.5% ground glass diffuser is achieved, which...

A new method to improve the focalization and efficiency of Figure Eight (FOE) coil in rTMS is discussed this paper. In order decrease half width distribution curve (HWDC), as well increase ratio positive peak value negative (RPN) induced electric field, a shield plate with window ferromagnetic block are assumed enhance electrical field. The made highly conductive copper, permeable soft magnetic ferrite. computer simulation conducted on ANSYS® software conduct finite element analysis (FEA)....

A novel waveguide-fed antipodal exponential tapered slot antenna (AETSA) is investigated to achieve wideband circular polarization. The proposed AETSA fed by double-ridge waveguide and loaded with slots. axial ratio (AR) performance discussed in detail. It noted that this has a right-hand circularly polarized AR lower than 3 dB 94.5% bandwidth, from 12.4 34.6 GHz, illustrating AETSAs potential application. measured VSWR 2.1 the operating band. Gain varies 8.3 18.3 dBi. This suitable for...

In this paper, a multivariate cooperative internal mode control method based on RBF neural network (RBF-NN) inverse system is proposed to suppress the chaotic behavior in power system. Firstly, seven-dimensional model of controlled including energy storage (ES) and static var compensator (SVC) constructed, dynamics analyzed by local bifurcation diagram, attractor phase diagram timing merging crisis coexistence attractors are found under action low-frequency disturbance. Secondly, considering...

This paper presents a wideband tri-polarized antenna with center frequency of 2.4 GHz. The consists dual-polarized double-layer microstrip and printed monopole antenna. has three ports to produce mutually orthogonal polarizations (X-axis, Y-axis, Z-axis). Measured results show that VSWR is less than 2 from 2.3 2.5 GHz the isolation among these above 22dB. At GHz, gain greater 7.6dBi when polarization along X-axis 0.3dBi Z-axis. simple structure suitable for array application.

A Gaussian-weighted annular ultrasound array is proposed to reduce artifacts and extend the depth of field acoustical-resolution photoacoustic microscopy. By applying Gaussian weighting on each ring, suppresses side lobes by about 18 dB compared a conventional focused transducer, "X"-shaped are significantly reduced in images. Additionally, controlling delay time can dynamically focus at different depths, thus achieving long field. Experiments performed which demonstrate that scheme improve...

A fully metallic partially open corrugated waveguide (CW) is employed to construct the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> -band linearly polarized (LP) and circularly (CP) frequency-scanning (FS) periodic leaky-wave antennas (PLWAs) with spatial coverages from backward ( <inline-formula xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta &lt; 0$ </tex-math></inline-formula> ) forward &gt; ). The...