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To solve the problem that the Mass-to-Drag Ratio of the reentry target can't be extracted stably, a recognition method based on the height when the velocity of reentry target declines is proposed. The method extracts the height when the velocity of reentry target declines, because the air resistance on the light and heavy target is different. Then these two kinds of target with different Mass-to-Drag...
According to the linear coordinate transformation of metamaterial, we design 3-D arbitrarily non-conformal ellipsoidal cloaks, that is the inner and outer ellipsoidal shell has different focus, while existing theories about ellipsoidal cloak are confocal. Theoretical derivation about the permittivity and permeability tensors of metamaterial is demonstrated in this letter. We notice those tensors are...
The designing process of a ZigBee-Communication PCB (Printed Circuit Board) is presented. The layer-stack structure and through-hole structure for PCB via hole and pad are modelled firstly in HFSS simulation environment, and then the key designing parameters which affect the RF performance are identified and determined by simulation. The simulation result shows the PCB achieves 𢀒20dB return loss...
The existent problem of the weather radar data lies in its too large data which is not conducive to its storage and transmission. This paper put forward a hybrid compression algorithm of the weather radar data that consists of three steps including pre-compression, lossy compression and lossless compression. Firstly, the paper introduced the radar data's types and characteristics, analyzing the pre-compression...
At present, ground-based microwave radiometers are widely used for remote sensing of atmosphere, observing at elevation angles more than 15° with an atmospheric profile retrieval model, no considering the effects of atmospheric refraction and sea surface emission. In this paper, a low elevation angle brightness temperature model is proposed, taking the effects of atmospheric refraction, sea surface...
An ultra-wideband, high efficiency, and wide angle terahertz reflective polarization converter (RPC) using interlaced-parallel-dipole metamaterial (IPDMM) is theoretically demonstrated in this paper. Illuminated by linearly polarized (LP) wave, the proposed polarizer performances an excellent 90° linear polarized conversions at three resonance frequencies, and pure circularly polarized (CP) conversion...
There is a continuing requirement for simple, but representative methods for determining the height of maximum electron concentration of the F2-layer (symbol hmF2), both for communication and navigation. The techniques for estimating the F2-peak height hmF2 from M(3000)F2 are reviewed with particular stress put upon those in which the effects of underlying ionization are accounted for by a correction...
In this paper, a band-stop filter in Ka band is proposed, which is based on substrate integrated waveguide(SIW) resonators and complementary split ring resonators(CSRR). The SIW resonators filter is provided with high pass characteristics. We show that near the resonance point, the impedance characteristics is significantly increased by CSRR. Therefore, we can combine the SIW resonators and CSRRs...
This paper is based on the application requirements of fully polarimetric radar for near ground and sea targets detection. We have used numerical modeling based on integral equation and multilevel fast multipole algorithm to study and calculate the fully polarimetric far field scattering data of simple manmade targets in a half space to conduct radar imaging. We also have compared the differences...
A novel type of ultra-thin polarization conversion metasurface (PCM) that reduce radar cross section(RCS) for planar structure is presented. The proposed PCM is consist of split-ring resonators. By the design with mirror-arrangement of the PCM unit cell, a strong phase cancellation is achieved. The simulation results show that the proposed PCM can realize 5 dB RCS reduction in wide range from 8.6GHz...
This paper describes the design of a low profile and wideband antenna array with circular polarization. The antenna consists of 2 × 2 elements. Loop coupled structure and sequential rotation feeding technique are used to obtained wideband VSWR and axial ratio performances. The proposed antenna array is analyzed with HFSS software. The VSWR, Axial Ratio, and Radiation Patterns of the array are presented...
A novel main beam angle control microstrip antenna is designed and fabricated by loading a monolayer transmissive phase gradient metasurface (PGM). The anomalous refraction effects of the PGM are able to introduce predefined wave vector to control the radiation direction. The resonant frequencies of the four different PGM loaded antennas are kept at 9 GHz when the height of the cavity is fixed. However,...
Impedance matching is the essential requirement in the design of a coaxial structure. The abrupt change of the inner and outer diameter of the coaxial structure will lead to the change of its characteristic impedance, and then enormous reflection would be excited if the failure of the proper design. In this article, a structure of multistage gradient coaxial is built, which is based on the axial dislocation...
Based on the experimentation system of underwater electric field, the corrosion related static electric field produced by ship's physical scale model in the context of simulated seawater, is measured and analyzed, to investigate the distribution of ship's static electric field. Several instances are discussed, with different position arrangement or output electric current of anodes. It may provide...
This paper proposes a method to estimate the unknown angular location of a bi-static multiple input multiple output (MIMO) radar target in the low angle scenario. The multipath model is formulated, in which the specular reflection is treated as an image target and the diffuse reflection is taken as spatial correlated stationary Gaussian noise. Based on this model, the colored noise is cancelled by...
An Ortho-mode Transducer(OMT) used for Dual-beam and dual-polarization reflector antenna is proposed for the problem of large lateral offset-focus. The matching of the transducer is analyzed by analyzing the electronic properties of the waveguide. The experimental results are in good agreement with the numerical simulations. Compared to the traditional OMT used screws outside the waveguide, this new...
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