Jui-Pang Hsu

Further study on two-thickness-method for simultaneous measurement of complex EM parameters based on open-ended coaxial probe

Two-thickness-method (TTM) based on an open-ended coaxial probe is investigated in this paper with an emphasis on uncertainty analysis. Uncertainty equations in differential forms are established for the simultaneous measurement of complex electromagnetic (EM) parameters, i.e. permittivity /spl epsiv/ and permeability /spl mu/, in the systematical consideration of all error factors in measurement. A numerical analysis is carried out to provide the relations between the uncertainties and test samples thicknesses via 3D figures, while the influence of the coaxial lines dimension on the measurement accuracy is also included based on the same analysis method. The comparisons between the measured errors and theoretical uncertainty prediction are given for several samples, which validate the effectiveness of our analysis.

Proposal of Surface-Wave Planar Circuit, Formulation of its Planar Circuit Equations and its Practical Application

This paper proposes the concept of a surface-wave planar circuit and formulates surface-wave planar circuit equations based on Maxwells equations. As examples of the application of these equations to practical problems, step discontinuity, planar-type transmission line and circular-shaped resonator of covered image-line type are considered.

Electric field distributions in microwave planar circuits by small coaxial probe and comparison with FDTD method

A detailed investigation of the 2D electric field distributions in bandpass filter elements that consist of microwave planar structures such as microstrip and coplanar waveguide is very useful for physical understanding, accurate and high-speed filter design and studies of electromagnetic coupling effects. By using a small electric coaxial probe, two dimensional electric field distributions for filter elements are measured. The proposed measurement system is very simple, wideband and accurate and does not required complicated system. Comparing the FDTD calculated results with measured results, the agreement is good. The upper limit of the operating frequency and the spatial resolution for the measurement system is clarified.

New synthesis method for a branch-line 3 dB hybrid: a hybrid approach comprising planar and transmission line circuit concepts

A synthesis method for a stripline-type branch-line 3-dB hybrid which is based on an equivalent circuit derived by the planar circuit approach is presented. The equivalent circuit of an ideal 3-dB hybrid is derived first from those of the segmented circuit elements, i.e., four three-port junctions and four quarter-wave transmission lines. A systematic synthesis process is then developed upon the basis of the equivalent circuit. Practical hybrid circuit having optimized circuit patterns which were constructed for center frequencies of 3, 5, and 7 GHz are discussed. Their measured characteristics are described. The results are shown to agree well with the theory. >

Two Dimensional Electric Field Measurement in Microstrip-Line Circuits by Coaxial-Type Probe

A detailed investigation of the electromagnetic field distributions in high frequency printed circuits and high-speed interconnects is very useful for physical understanding, studies of electromagnetic coupling effects for EMC and EMI and for optimization of electromagnetic circuit designs. The aim of this paper is to show how to measure the electric field distributions in electromagnetic circuits. An electromagnetic analysis for microstrip-line circuits is carried out by using a finite-difference time domain technique and its measurement is carried out by using a small probe antenna. The measurement results are in fairly good agreement with those of the numerical analysis using the FDTD method. Thus, the measurement system offers a valid means for predictions in the theoretical analysis of more complicated discontinuity problems.

Calculation of Foster-type equivalent network for stripline 45 degrees bend based on novel calculation method of the eigenmode

Foster-type equivalent network for stripline 45 degrees bend of equal or different stripline width is derived based on eigenmode method. The key step is how to calculate eigenmodes of the planar junction of 45/spl deg/ bend up to necessary mode number with exactness. We propose a new idea of three stage cascade-connected stripline configuration and double symmetry with magnetic wall, which is practically carried out with success. The derived equivalent network is applied to the calculation of frequency characteristics and field distribution under the operating.

The Foster Type Circuit For The H-matrix And Application to Coupled Line Filter of Even Order

The Foster-type circuit of even order is realized in a simple configuration by use of the H-matrix. The Foster-type circuit has some superior properties to those of the popular ladder networks. Conventionally, the Foster-type circuits are designed by applying the eigen-mode expansion method only to the Z matrix or the Y matrix. This process is well suited for the realization of the circuits of odd order, and hence the axial symmetrical structure is readily realized. However, in this conventional scheme it is difficult to design the Foster type circuit of even order and the axial anti-symmetrical structure, although the theoretical network synthesis itself is possible. This paper shows that the H-matrix and the G-matrix have complementary characteristics to those of the Z-matrix and the Y-matrix for the Foster-type circuit. We show that the circuit of even order and hence the axially anti-symmetrical structure is well realized by the H-matrix. To demonstrate the usage of these properties, an even order band pass filter of the Foster-type circuit is designed based on the H-matrix.

Measurement of Surface EM Field of Planar Circuit in Microwave Frequency

A field mapping system used in microwave frequency band is established for the purpose of surface field detection. A section of coaxial line with a protruded inner conductor is used as an electric probe, while a new compact CPW-type loop probe is designed as a magnetic probe. The electric probe used here has a very high sensitivity and could be used up to 18 GHz. The new designed magnetic probe has a very simple structure, compact size of 2.3X2.3 mm and good seIf resonance suppression characteristics, in order to verify the effectiveness of this field mapping system, the EM field distribution of a section of short circuited microstrip line is scanned. By comparing the measurement results with the theoretical ones obtained by 3D simulator (CST MWS), the good performance of the new proposed probes are validated.

Equivalent Network Approach for Field Analysis of 3-D Optical Waveguide Step Discontinuity and their Dynamic Behavior

Exact analysis of step discontinuity of 3-D optical waveguide is important for exact design of optical integrated circuit. Mode theory is introduced to derive the equivalent network in lateral direction and that in waveguide direction. The former is used to calculate waveguide propagation mode, which leads to the equivalent network along waveguide direction. The latter is used for field analysis of step discontinuity of 3-D optical waveguide. Two kinds of so far derived equivalent network are used to give reasonable analytical results with success.

Analysis of Propagation Eigenmode for Stripline based on Planar Circuit Equations and Lateral Equivalent Network

Stripline/microstrip line is an important waveguide component for MIC. Theoretical treatment of propagation eigenmode for stripline/microstrip line of infinitesimally thin strip has been established. However, theory for thick strip line is not yet established. In order to treat propagation eigenmode of stripline/ microstrip line with thick strip, rigorous equivalent network in the lateral direction is derived based on mode analysis and planar circuit theory. Derived equivalent network is practically applied to the analysis of propagation eigenmode for stripline of any thickness with success