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The idea of Ku-band transceiver frequency conversion module design based on 3D micropackaging technology is proposed. By using the double frequency conversion technology, the dual transceiver circuit from Ku-band to L-band is realized by combining with the local oscillator and the power control circuit to complete functions such as amplification, filtering and gain. In order to achieve the performance optimization and a high level of integration of the Ku-band monolithic microwave integrated circuits (MMIC) operating chip, the 3D vertical interconnection micro-assembly technology is used. By stacking solder balls on the printed circuit board (PCB), the technology decreases the volume of the original transceiver to a miniaturized module. The module has a good electromagnetic compatibility through special structure designs. This module has the characteristics of miniaturization, low power consumption and high density, which is suitable for popularization in practical application.

A novel planar printed log-periodic dipole array (LPDA) antenna fed by tapered microstrip line (MSL) to double sided parallel strip line (DSPSL) is proposed in this paper. The proposed antenna adopts MSL feeding approach from backside. Using this feeding technique makes the printed LPDA antenna easier to be integrated into radio frequency (RF) circuits. In this paper, four layers are used to construct the antenna. The four layers of the printed LPDA antenna are printed on three thin dielectric substrates which are integrated together. To validate this approach, a printed LPDA antenna is simulated and fabricated for operating in the S and C bands (2.5–6 GHz). The antenna showed a good result over the whole frequency range with 2 : 1 VSWR, an average gain of 6.5 dB, and stable radiation patterns. The measured results are in very good agreement with simulations.

In this letter, a segmentation method is proposed based on an adaptive Bayesian non-local MRF (ABNL-MRF) model. Aimed at the multiplicative speckle existing in SAR images, a patch-similarity measure based on a ratio of probability is introduced firstly. Then non-local similar pixel-blocks are adopted to guide the segmentation of the noisy image. However, non-local method over-smoothes edge regions and makes them inaccurate though it is robust for speckle. A rectification index is designed according to the homogeneity degree of local window. Based on the value of rectification index, a non-local constraint term is adaptively integrated into the potential function. Thus a suitable prior is defined that guarantees both the smoothness of the denoised image and the preservation of its structure. Experimental results demonstrate the very good performance of the proposed method.

Alternating direction implicit finite difference time domain (ADI-FDTD) method is unconditionally stable and the maximum time step is not limited by the Courant stability condition, but rather by numerical error. Compared with the conventional FDTD method, the time step of ADI-FDTD can be enlarged arbitrarily and the CPU cost can be reduced. 2D perfectly matched layer (PML) absorbing boundary condition is proposed to truncate computation space for ADI-FDTD in dispersive media using recursive convolution(RC) method and the 2D PML formulations for dispersive media are derived. ADI-FDTD formulations for dispersive media can be obtained from the simplified PML formulations. The scattering of target in dispersive soil is simulated under sine wave and Gaussian pulse excitations and numerical results of ADI-FDTD with PML are compared with FDTD. Good agreement is observed. At the same time the CPU cost for ADI-FDTD is obviously reduced.

The high cross-polarization of the microstrip integrated balun-fed printed dipole antenna cannot meet the demands of many engineering applications. This kind of antennas has high cross-polarization levels (about −20 dB). And we find that the high cross-polarization radiation is mainly produced by the microstrip integrated balun rather than the dipole itself. The very limited method to lower the cross-polarization level of this kind of antennas is to reduce the substrate thickness. In this paper, to improve the low cross-polarized performance, firstly, an equivalent model is presented to analyze the cross-polarization radiation. Secondly, a novel structure with low cross-polarization is proposed. The microstrip integrated balun is enclosed by a center slotted cavity. The E-field of the microstrip integrated balun is transformed parallel to the dipole arms by the slot, so the radiation of the cross-polarized component is suppressed. Measured results show that this structure can achieve a bandwidth wider than 40% while reducing the cross-polarization level to less than −35 dB within the frequency band.

A new frequency-selective surface (FSS) with loadings is introduced in this paper and analyzed by way of period moment methods (PMMs). The simulated results show that FSS may operate in different bands and especially generate a large reduction in the resonant frequency for a fixed unit cell size through different loadings. This provides a new orientation in the development for FSS. Practical circuits are fabricated, and the measured results agree well with the simulated results.

The picosecond photoconductive switches are developed and used to detect the pulse laser waveform. By using the photoconductive switches, an novel lab model of ultra-wide band(UWB) radar is also developed. The experimental results are given to show the performances of the switches and the UWB radar.

A novel finite-difference time domain (FDTD) algorithm named equivalent circuit FDTD (EC-FDTD) is realized, which introduces lumped elements from transmission line theory into Yee cell. It includes lumped elements such as series inductance and shunt capacitance in the right-handed materials, as well as shunt inductance and series capacitance in the left-handed materials. Due to its promising physical thoughts, it can be easily generalized to arbitrary dispersive materials including frequency selective surfaces and metamaterials. The technology of streaming single-instruction multiple-data (SIMD) extensions (SSE) was proposed by Intel and is currently utilized in personal computers. SSE is a kind of parallel speedup technology in one core. The speedup can be achieved four times in principle without changing hardware. Combined with SSE, the EC-FDTD can be apparently accelerated. Twice speedup is achieved in the tests of this paper. The algorithm of EC-FDTD is utilized to design the wideband metamaterials absorbers by employing the single square and double square loops loaded with the lumped resistors. The invisible radome has a great impact on reducing the radar cross section of the antenna out of band. The radome is designed with operating frequency to be 1 GHz and the absent bandwidth from 3 GHz to 9 GHz by the algorithm. And then these prototypes are fabricated and measured. From the comparative results, the correctness of EC-FDTD and the speedup of the SSE are both verified.

We experimentally investigate the discrete mode in the zero-average-refractive-index gap (the zero-n—gap) of the one-dimensional periodical structures containing left-handed materials (LHMs) and right-handed materials (RHMs). When the discrete mode conditions are satisfied in the zero-n gap, there are no discrete propagating modes, but the zero-n—gap completely vanishes. This behavior is attributed to the dispersive property of LHMs and RHMs. In addition, the theoretical expectation of the discrete modes with no sidelobes in the zero-n—gap never occurs in experiment because the LHMs is intrinsically dispersive.

A transmission line model capable of predicting the reflection phase of high impedance surfaces in normal incident is proposed. The surface impedance of high impedance surface （HIS） can be regarded as the effective capacitive impedance of patch array in parallel with the inductive impedance of substrate layer, and the effect of vias conductor can be ignored at normal incidence. Results of the a nalytical model agree well with the HFSS simulated results. HIS with different parameters are fabricated and tested, the reflection phase of HIS predicted using the transmission line model agree well with the measured results, which proves the validity of this transmission line model.

Magnetized plasma photonic crystals are artificial periodic structures composed of magnetized plasmas and dielectric structures (or vacuum).In this paper,the piecewise linear current density recursive convolution (PLCDRC) finite-difference time-domain (FDTD) method for magnetized plasmas is applied to study the magnetized plasma photonic crystals.The effect of parameters of magnetized plasma on electromagnetic band gap is presented.In time-domain,the electromagnetic propagation process and reflection/transmission electric field of Gaussian pulses through magnetized plasma photonic crystals are investigated.In frequency-domain,the reflection and transmission coefficients through magnetized plasma photonic crystals are computed.The results are discussed.

In this paper a kind of high impedance substrate surface covered with different dielectric layer is analyzed by periodic moment method, their band-gap diagrams are described. Meanwhile, the propagating property of surface wave of the high impedance ground plane with different dielectric covering is tested, the results of theoretic analysis are validated. Our results can be helpful for the design of high impedance ground plane with a dielectric cover layer.

The JEC finite-difference time-domain (JEC-FDTD) method is extended to three dimensional anisotropic dispersive media—the magnetized plasma. The problem which incorporates both anisotropy and frequency dispersion at the same time is solved for the electromagnetic wave propagation. The three dimensional JEC-FDTD formulations for anisotropic magnetized plasma are derived. The method is applied to the electromagnetic scattering of dihedral corner reflector and sphere-cone coated with anisotropic magnetized plasma. By simulating the interaction of electromagnetic wave with magnetized plasma, some numerical results are obtained, which indicate that an appropriate plasma coating may efficiently reduce the RCS of a metallic target.

Plasma photonic crystals are artificially periodic structures, which are compose d of plasmas and dielectric structures (or vacuum). In this paper, the piecewise linear current density recursive convolution (PLCDRC) finite-difference time-do main (FDTD) method is applied to study the plasma photonic crystals and those co ntaining defects. In time-domain, the electromagnetic(EM) propagation process an d reflection/transmission electric field of Gauss pulses passing through the pla sma photonic crystals are investigated. In frequency-domain, the reflection and transmission coefficients of the pulses through the two kinds of crystals are co mputed. The results illustrate that the plasma photonic crystals mostly reflect for the EM wave of frequencies less than the plasma frequency, and mostly transm it for EM wave of frequencies higher than the plasma frequency. In high frequenc y domain, the plasma photonic crystals have photonic band gaps, which is analogo us to the conventional photonic crystals.

The uniplanar compact photonic_bandgap (UC_PBG) is a periodic planar layered str ucture which is constructed in the microstrip structures. In this paper, the sub strate is regarded as an uniaxial anisotropic medium, and the UC_PBG is analyzed using the method of lines (MoL). The process of MoL is described in detail, som e UC_PBGs with different dielectric parameters are computed. It is shown that th e complete band gaps or even larger ones appear in dispersion diagram of those UC_PBGs.

The finite-difference time-domain(FDTD) method is extended to two dimensional anisotropic dispersive media-magnetized-plasma using Z transformation for the f ist time. The problem which incorporates both anisotropy and frequency dispersio n at the same time is solved for the electromagnetic wave propagation. The two d imensional FDTD formulations for anisotropic magnetized plasma are derived. The method is applied to the electromagnetic scattering of perfectly conducting cyli nder coated with anisotropic magnetized plasma. By simulating the interaction of electromagnetic wave with magnetized plasma, some bistatic numerical results ar e obtained, which indicate that an appropriate plasma coating may efficiently re duce the RCS of a metallic target.

A JEC finite-difference time-domain (JEC-FDTD) methodology for dispersive media is extended to anisotropic magnetized plasmas. The problem which incorporates both anisotropy and frequency dispersion at the same time is solved for the electromagnetic wave propagation. The JEC-FDTD formulation for anisotropic magnetized plasmas is derived. The high efficiency and accuracy of the method are confirmed by computing the reflection and transmission through a magnetized plasma layer, with the direction of the propagation parallel to the direction of the biasing field. A comparison with frequency-domain analytic results is included.

A novel finite-difference time-domain (FDTD) method, called piecewise linear current density recursive convolution method,is developed for dispersive media. The formulation of this method is derived using the convolution relationship between the current density and the electric field. The high accuracy and efficiency of this method are confirmed by computing the reflection and transmission coefficients of electromagnetic waves through a collisional plasma slab in one dimension.

A PLJERC-FDTD algorithm is applied to the study of the scattering of perfectly conducting cube covered with homogeneous isotropic plasmas. The effects of plasma thickness, density and collision frequency on the radar cross section(RCS) of the conducting cube scatterer have been obtained. The results illustrate that the plasma cloaking can greatly reduce the RCS of radar targets, and the RCS of the perfectly conducting cube scatterer decreases with increasing plasma thickness when the plasma frequency is greatly less than the electromagnetic(EM) wave frequency; the RCS of the perfectly conducting cube scatterer decreases with increasing plasma thickness and plasma collision frequency when the plasma frequency is almost half as much as the EM wave frequency; the effects of plasma thickness and collision frequency on the RCS of the perfectly conducting cube scatterer is small when the plasma frequency is close to the EM wave frequency.

An auxiliary differential equation finite-difference time-domain (ADE-FDTD) methodology for anisotropic magnetized plasmas is derived. The method is based on a difference approximation of the auxiliary differential equation. A comparison with the JEC method is included. The CPU time saving by several times and accuracy of the method are confirmed by computing the reflection and transmission through a magnetized plasma layer, with the direction of propagation parallel to the direction of the biasing field.