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This paper will present the recent development of large-signal modeling cum PA design based on Dynax GaN HEMT devices. A modified Angelov model is used to model the pulse I-V data. Improved modeling results to address the trapping effect will be given together with new model parameter extraction methodology. A new Large Signal model purpose with trapping effect. Design Power Amplifier in the purpose...
Recently, a point-by-point active millimeter wave imaging system with shortened imaging time and reduced system cost and complexity is proposed. Demand for a mask to shape transceiver beam arises accordingly. Absorbing materials plays a critical role for the mask. Design of thin multilayer planar absorber in this paper. Differential evolution (DE) algorithm is implemented to solve the equivalent multi-dimensional...
Pursuing higher speed of digital signal processing is the non-stop goal for human. When digital filter has been chosen, how to upgrade the speed of filter signal processing is a challenge for software engineer. This paper analyzes the techniques of sliding window and pipeline, and illustrates the application with two order Butterworth filter as an example. These techniques can condense the signal...
An ultra-wideband metasurface is designed for suppressing the specular electromagnetic wave reflection or backward radar cross section (RCS). Square ring structure is chosen as the basic meta-atoms. A new physical mechanism based on size adjustment of the basic meta-atoms is proposed for ultrawideband manipulation of electromagnetic (EM) waves. Based on hybrid array pattern synthesis (APS) and particle...
A novel broadband circularly-polarized (CP) antenna fed by strip-line is proposed. The CP operation is achieved by corners truncated and can be significantly improved by introducing a pair of half loop strips around two opposite corners of the square patch. The bandwidths for the axial ratio (AR < 3 dB) and relative impedance (|S11| < −10 dB) is 7.6% (16–17.2 GHz). The proposed antenna also...
Two topology optimization methods, namely material distribution and level-set methods, are used for optimization of microstrip antennas. By successive application of the two methods, the optimization process can take advantage of the powerful topology-searching ability of the material distribution method and the feature of generating structures with smooth and low-sensitivity boundaries of level-set...
Localized surface plasmon resonances (LSPR) give rise to enhanced fields near the interface between the metallic and dielectric boundary. Strong excitation intensities can lead to the formation of photothermal bubbles around plasmonic nanoparticles. Numerical simulation is indispensable in predicting and analyzing plasmonic bubble as the measurement is always too expensive or too complicated to be...
A compact dual-band spiral antenna is proposed for on-body applications in this paper, operating at 402 MHz Medical Device Radiocommunications Service (MedRadio) band and 2.45 GHz Industrial, Scientific, and Medical (ISM) band. Initially, a spiral-shaped dipole is adopted to form a miniaturized wearable antenna resonant at 402 MHz to communicate with implanted devices. In addition, four rectangular...
The existing half-duplex relay-based device-to-device (D2D) communication equips with single antenna infrastructure and receives and transmits signals in two equivalent slots which lead to poor performance in term of rate achievement. To solve this problem, we propose a new relay-based D2D scheme with two-antenna infrastructure and bring in slot splitting factor to divide one frame into double unequal...
Traditional FAST feature points extraction algorithm are widely used in object detection, target tracking and image matching. Generally, the detection threshold of FAST algorithm is a constant which is determined artificially before the experiment. It can't satisfy the extract requirement of different image feature points. Moreover, a single threshold does not suitable for images with large changes...
An efficient fully automated EM-level design framework is implemented using Matlab, Sonnetlab toolbox and Sonnet EM simulator for the design of different type of sequentially coupled resonator planar filters. The proposed implementation integrates the space mapping technique and reflected group delay method to achieve fast and reliable EM-based filter design. In this paper, two design examples are...
This paper presents the design of novel surface that can convert the incident EM-waves into its cross-polarized (orthogonal) component at millimeter wave frequencies. The unit cell composing the surface has a cut of wire along the diagonal with two closed rings above and below. The unit cell has three resonance frequencies at 84.32GHz, 85.6GHz, and 87.38GHz at which the polarization conversion reaches...
This paper proposes a single-layered dual-band patch antenna using a CRLH mushroom-like metamaterial structure. The antenna is compact, it can achieve maximum gains of 2.29 dBi at 2.76 GHz and 7.06 dBi at 4.27 GHz, with a monopole-like and a patch-like radiation pattern, respectively. The bandwidths for the reflection coefficient less than −10 dB are 28 MHz at the low frequency band and 130 MHz at...
Based on the equivalent source and NMM (numerical mode matching method), the theory model method of electromagnetic signal transmission for down-hole to surface by is established. The gap antenna and toroid were calculated, the influence of the input impedance and of incentive to drill string current is analyzed, through calculation and comparison that the gap antenna method is more suitable for the...
Water occurring on earth has always been equipped with the characteristic of frequency dispersive permittivity at microwave frequency, which thus can be seen as a promising constituent material for broadband electromagnetic wave absorption. Here, we develop water as ultrathin dielectric substrate standing on the metal backplane to construct three-dimensional grid array, which can acquire broadband...
This paper proposed a miniaturized wideband implantable antenna operating at MedRadio band for Medical Body Area Network (MBAN) devices. The operating frequency of the proposed antenna covers from 334 to 441 MHz for the simulated result, which is robust enough to withstand the frequency shift brought by different human beings. The footprint of the designed antenna covers a planar area of only 14 mm...
A novel wideband dual-polarized magneto-electric dipole unidirectional antenna is proposed in this paper. The antenna is composed of dual-layer magneto-electric (ME)-dipole and two Γ-shaped probes. Its two ports both achieve a common impedance bandwidth of 91.6%(SWR<2). The antenna has excellent performance in isolation, which is more than 15dB, and a high front-to-back ration more than 14.8dB...
A wideband microstrip endfire antenna is designed for applications in base station and satellite communication. Utilizing substrate integrated waveguide technology, vertically polarized wave is generated by the driven element of the antenna. And a parasitic microstrip patch with one edge opened and the other three edges shorted is introduced as the magnetic dipole to improve the impedance matching...
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