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A brief introduction of the gyrotron is given focusing on the design of the magnetic system design. A discussion about various possible solutions for the magnetic system is undertaken and the advantages and disadvantages for the each example are given. Requirements for the construction are presented and justification for the choice of the given solution is provided. Initial design simulations for...
In the paper a planar circular model (20-by-20 µm in size) of a band-pass multiplexing filter, based on 2D photonic crystal with original “dewdrop-petal” inner structure has been considered. The frequency selectivity of this filter is due to its geometry, built on the base of nature processing physical system - a flower with dewdrops on its petals. The filter has been PCsimulated on TE electromagnetic...
This paper presents a novel algorithm for accelerating 3D Finite Element Method simulations by introducing macromodels created in local model order reduction in the selected subdomains of the computational domain. It generates the projection basis for a compact system of equations associated with a separate subdomain. Due to non-linear frequency dependency in the Right Hand Side (RHS), the standard...
A method of estimation of a single balun S parameters based on the measured parameters of back-to-back configuration is presented in the paper. Proposed approach is to measure two back-to-back circuits: i) direct connection of baluns and ii) connection with additional transmission line segment between the baluns. Coupling effects in both circuits are calculated from full-wave simulations. Next they...
A method of moments combined with mode matching technique is applied to analyze the shielded coupled strip and slot line structures containing a thin plate of Ω pseudochiral medium. The boundary problems are simplified by introducing for Ω-medium the approximate continuity conditions. Such mathematical model allows to examine the field displacement effect appearing in the considered guide resulting...
This paper describes a phase-error compensation method employing the digital predistortion for pulsed power amplifiers in radar applications. The predistortion method was evaluated for the power amplifier based on the commercially available Avago ATF52189 HEMT at frequency 1.3 GHz. The measurement setup and the extraction procedure of the inverse model of the power-amplifier phase distortion is presented...
This paper presents the original synthesis method for band-pass filters, that allowable are arbitral transmission zeros occurring at each side on the pass-band. This method employs const J-inverters and polynomial effective-linearization of band-stop reactances. Proposed synthesis is of course an analytically simply solvable. Attained frequency responses of designed filters give expected sufficient...
In this paper an analytical model is developed to characterize the performance of GaN-based microwave HEMTs. To theoretically predict mobility and sheet carrier concentration in 2-dimentional electron gas (2DEG) of GaN HEMTs extraction procedure is proposed. Presented model is based on physical relationships and I–V characteristics without introducing any semiempirical parameter. Results are compared...
In this paper, we present a fast technique for an automated design of microwave filters in substrate integrated wave (SIW) technology. The proposed methodology combines the space mapping technique with a cost function defined using the location of complex zeros and poles of filter's transfer and reflection function and uses a rectangular waveguide as a surrogate model. The effectiveness of the proposed...
Ultra-wideband positioning systems intended for indoor applications often work in non-line of sight conditions, which result in insufficient precision and accuracy of derived localizations. One of the possible solutions is the implementation of cooperative positioning techniques. The following paper describes a cooperative ultra-wideband positioning system which calculates tag position from TDOA and...
Numerical approach to frequency response problems usually requires that the system governing equation is solved repeatedly at many frequencies. The computational efficiency of the overall process can be increased by departing from traditional sequential computing model in favor of utilizing the parallel processing capability commonly offered by modern hardware. In this paper, we consider a hybrid...
A new method for solving scattering from a cylinder partially buried in a material half space for TMz polarization is presented with example scenarios. The surface equivalence principle is used with the decomposition method in order to calculate the current densities in the calculation domain. The Method of Moments (MoM) is used to solve the electric field integral equations (EFIE) in the frequency...
Equivalent circuit field-effect transistor models (compact models) are extensively used in integrated circuit design and manufacture. The most commonly used models are not derived from basic physical fundamentals, but are rather determined by parameter extraction techniques from experiment. This requires that the device be fabricated and characterized before the model can be determined. An alternate...
Carbon Nanotubes (CNT) and graphene as a whole have been of interest since their discovery due to their unique properties. These include, but are not limited to: high electron mobility in room temperatures, relatively high thermal conductivity and possibly the highest resistance to mechanical stress. Hence, it is important to properly model structures and systems that might use graphene in future...
GaN High Electron Mobility Transistors (HEMTs) are very promising for radiofrequency applications and especially RADAR operation due to their ability to work at high power densities. However, parasitic effects like traps are a common issue on this type of technology. They have to be properly characterized in order to be compensated. Several measurement methods exists like DLTS or DLOS, mostly consisting...
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