Analysis of EM scattering in Waveguide Filter using Neural Network
This paper discusses the application of Neural Network (NN) technique in the modeling of a typical electromagnetic (EM) field scattering problem in a waveguide filter structure [1]. The structure under consideration is a rectangular waveguide with four dielectric circular rod inserted symmetrically. The Neural Network takes into consideration the geometrical and material parameters of the EM model of the structure and the reflection coefficient values for different frequencies in the frequency band of interest. The Neural Network is trained off line using training data sets generated by the image theory. The work is to find out an acceptable Neural Network model of the waveguide structure having four dielectric post, verification using Method of moment by simulation and the corresponding filter structure practically implemented in hardware for verification.
Artificial neural network design of stub microstrip band-pass filters
In this paper, an artificial neural network (ANN) design technique for a stub microstrip band-pass filter is presented. Essential dimensions of the microstrip filter layout are used to get the relationship of the input-outputs for ANN model. This paper presents the design and analysis of stub microstrip band-pass filter at mid-band frequency 1.8 GHz, which produced improved bandwidth and minimum insertion loss of –0.5899 dB and return loss of –36.67 dB. Artificial neural network architecture has been proposed to determine the magnitude variation of scattering parameters (S-parameters) of the microstrip band-pass filters for various dimensions. The ANN model produced has been exposed to be as exact and veracious as an EM simulator and it is computationally more effective in the design. The simulation is performed using the commercial software IE3D 14.1 and ANN training of S-parameters are performed in MATLAB 7.1.
An analytical approach to the design of electrodes in high-power, fast-transverse-flow CO2 lasers
Abstract Usually, the design of the electrodes of fast-transverse-flow CO 2 lasers relies more on experimental data than on theoretical analysis. Traditional systems sustain a stable, high-power discharge but the current distribution generates a peaked, non-uniform small-signal-gain pattern. We present a theoretical model suitable for the design of electrodes that achieves a quasi uniform gain distribution. The analysis, based on a two-temperature model and the gas-transport equations, computes the electron density that supports a flat gain pattern. Combining the desired electron density with the electron-balance equations, the model determines the required electric field. The results were used to design a new set of electrodes for a home-made fast transverse flow CO 2 laser. A stable, large volume discharge ( 4 × 8 × 90 cm 3 ) with very good uniformity was obtained. The resulting gain distribution was registered in a bi-dimensional map. The peak gain rose from 1.2 m - 1 , attained with the old electrode set, to 1.6 m - 1 with the new one and the gain showed a homogeneous profile.