Wave-based Modeling and Analysis of Microstrip Stub-line Structures (original) (raw)

Using z-variable Functions for the Analysis of Wave-based Model of Microstrip Stub-line Structure

2009

An efficient method based on transfer parameter approach is proposed to obtain the scattering parameters in z- domain of planar microstrip stub-line structures. A wave digital network (WDN) represents a digital model of the structure. WDN is composed of cascaded uniform segments and three-port adaptors with open stubs connected to their dependent ports. Uniform segments (transmission lines and stubs) are represented by several cascaded unit elements. Also, a simple modeling approach of the T-junction discontinuity which involves changing line lengths is given here. A simulation validation of the proposed modeling and analysis approach is provided by means of an open T-resonator circuit realized in microstrip technique.

Direct analysis of wave digital network of microstrip structure with step discontinuities

2008

A microstrip structure, divided into cascade connection of uniform sections, can be efficiently modelled by wave digital network [4]-[7]. Appropriate choice of a section number in digital model of microstrip structures is very important because of direct influence on the sampling frequency of the digital model, and on accuracy of desired response. Also, effects of the identified step discontinuities have to be compensated. In this paper, a choice of minimal number of sections based on given relative error, and one wave digital element for the step discontinuity are presented. Verification of the obtained results is done on one example of lowpass filter.

Wave Digital Approach-A Different Procedures for Modeling of Microstrip Step Discontinuities

2009

A theoretical model for the modeling of the microstrip structure as well as one type of regular discontinuity (step) is described. A microstrip structure, divided into cascade connection of uniform sections, can be efficiently modelled by wave digital networks. A wave digital network is a model of the microstrip structure modeled by wave digital elements. Appropriate choice of a minimal section number in that model is very important because of the direct influence on the sampling frequency of that digital model, and on accuracy of the desired response. Also, it is very important to achieve a good compensation of the effects of identified step discontinuities. In this paper, a choice of a minimal number of sections based on the given relative error and four different procedures for modeling the equivalent network of step discontinuity are presented. First of all, a wave digital element is formed for the equivalent T-network of the step discontinuity. In other procedures, the equivale...

A simple theoretical model for rectangular microstrip resonator with stubs

Microwave and Optical Technology Letters, 2004

ness, two cases, with or without consideration of the edge admittance, are studied. In both cases, the noise profiles are very different (with or without the abovementioned consideration). The peaks of these noise signals appear at about 28.5 and 236.5 ps, which correspond to the falling and rising edges of the input digital signal. Neglecting the edge admittance introduces 7% and 37% errors in the peak-to-peak noise for the thin and the thick substrates, respectively. In these cases, neglecting the edge admittance tends to overestimate the peak noise. CONCLUSION The radiation effect on via coupling in a power-return plane has been studied. Numerical examples were given to demonstrate the radiation effects on via-to-substrate coupling. It was observed that without consideration of the radiation effect, the analytical approach tends to overestimate the peak-to-peak noise. As the substrate thickness increases, the radiation loss may become comparable to the dominant dielectric loss and, hence, radiation effects must be considered in order to accurately predict the coupled noise. 2. J.C. Parker, Via coupling within parallel rectangular planes, IEEE Trans Electromagn Compatibility 39 (1997), 17-23. 3. M. Xu and T.H. Hubing, The development of a closed-form expression for the input impedance of power-return plane structure, IEEE Trans

Equivalent network modeling of slot coupled microstripline to waveguide transition

IEEE Antennas and Propagation Society Symposium, 2004., 2004

An analysis method of slot-coupled microstripline to waveguide transition is presented to develop a simple but accurate equivalent circuit model. The equivalent circuit consists of an ideal transformer, microstrip open stub, and admittance elements looking into a waveguide and a half space of feed side from a slot center. The related circuit element values are calculated by applying the reciprocity theorem, the Fourier transform and series representation, the complex power concept, and the spectral-domain immittance approach. The computed scattering parameters are compared with the measured, and good agreement validates the simplicity and accuracy of the proposed equivalent circuit model.

A Method for Calculating the Frequency-Dependent Properties of Microstrip Discontinuities

IEEE Transactions on Microwave Theory and Techniques, 1977

Afrstract-A method is described for enlcrdating the dynamical (frequency-dependent) properties of varions microstrip discontinuities such as unsymmetrical crossings, T junctions, right-angle bends, impedance steps, and filter elements. The method is applied Ito an unsymmetrical T junction with three different linewidths. Using a wavegnide model with frequency-dependent parameters, a field matching method proposed by Kiihn is employed to compute tlhe scattering matrix of the strictures. The elements of the scattering mntrix calculated in this way differ from those derived from static methods by a bigher frequency dependence, especially for frequencies near tlhe cutoff frequencies of the higher order modes on the microstrip lines. The theoretical results are compared with measurements, and theory and experiment are fonnd to correspond closely.

Microstrip Line Discontinuities Simulation at Microwave Frequencies

Advances in Physics Theories and Applications, 2013

Microwave and Millimeter wave integrated circuits (MICs) have experienced a tremendous growth over the last 50 years. Microstrip line is one of the popular lines in these MICs. Due to the layout necessities, an electromagnetic wave that propagates down a microstrip line may encounter discontinuities such as T-junctions, Bends and vias. A simulation model is presented here for analysing these discontinuities in microstrips through Sonnet Software. The parameters of microstrip lines are determined from the empirical formulae which are based on full wave analysis. The simulation work has been performed on Alumina substrate. The discontinuities are simulated and compensated which gives important results for designing high frequency microwave circuits.

An approximate parallel-plate waveguide model of a lossy multilayered microstrip line

Microwave and Optical Technology Letters, 2005

has been achieved. Slight discrepancies are due to mechanical tolerances of the fabricate prototype, which was built using mechanical etching . The total dimension of the filter is 35.0 mm, corresponding to 50% of the size of a conventional E-plane filter with same specifications. The upper 3-dB cutoff frequency is 9.49 GHz and more than 10-dB attenuation has been achieved at 9.5 GHz due to the finite transmission zero.