Joseph L. Tauritz

Systematic analysis, synthesis and realization of monolithic microwave active inductors

A unified analysis of monolithic microwave active inductors based on an amplifier-feedback topological description is introduced. Active inductors are classified based on the gain and feedback elements constituent to their design. Small signal, large signal and noise behavior are considered in the generic case. An illustrative example of the synthesis procedure for, as well as the measured results of a novel topology are presented.

Monolithic narrow-band active inductors using suspended membrane passive components on silicon substrate

In this paper 8.8 GHz monolithic narrow-band active inductors based on the DIMES-03 silicon bipolar process are reported. Substrate losses have been reduced using micro-machined suspended membrane inductors and capacitors. Consequently, higher working frequencies and lower power consumption, than those obtainable using a standard bipolar process, have been realized. Better noise performance is predicted. The results are particularly attractive in low power and low noise circuits.

A current‐matrix model for metallic and dielectric postwall waveguides

Waveguide structure integration in planar substrates for use in microwave components has received considerable attention in recent years. Waveguides with side walls consisting of cylindrical posts (postwall waveguides or PWWGs) are of interest, since they are compatible with standard PCB fabrication technology and exhibit low loss. In this paper we present an electromagnetic model for PWWG building blocks, whose characteristics are described entirely in terms of equivalent electric and magnetic surface currents at predefined port interfaces consistent with Lorentz’s reciprocity theorem. Introducing input and output surface currents, we determine the response of a block for a given port excitation. The expansion of the currents in terms of suitable bases results in a matrix that relates input and output currents. The scattering parameters of a building block are determined by expressing waveguide modes in terms of these bases. This facilitates the future integration of PWWG components in a microwave circuit simulator. We validate our model by comparing the results for simulated and measured uniform PWWGs implemented with metallic and dielectric posts.

Design and measurement of metallic post-wall waveguide components

In this paper we discuss the design and measurement of a set of metallic post-wall waveguide components for antenna feed structures. The components are manufactured on a single layer printed circuit board and excited by a grounded coplanar waveguide. For a straight transmission line, a 90° H-plane bend, and a H-plane T-junction, we compare measurements with simulations obtained from commercial software. In a next phase, the set of test components will be used to validate a software tool for component analysis. This tool is based on our own numerical method and will be integrated with a circuit simulator.

An Analysis Technique for Post-Wall Waveguides

In the last decade, post-wall waveguides have emerged as an interesting building block for (antenna) feed networks because of their potential low losses, low costs, ease of manufacturing and integrability with existing printed circuit board techniques. In this paper we present a general formulation to analyze the characteristics of post-wall waveguides with metal or dielectric posts. This formulation is based on a field expansion technique, applied to infinite arrays of posts. The modal behavior of post-wall waveguides is analyzed by considering the behavior of the field expansion coefficients as function of frequency and we compare our results with Ansoft HFSS simulations and measurements.

An electromagnetic model for post-wall waveguide building blocks

During the past five years, dielectric and metallic post-wall waveguides (PWWGs) have been analyzed at TNO Defence, Security and Safety, using both an integral equation approach and a modal approach. The model developed focuses on TEn0 modes facilitating the analysis of infinitely-long, straight PWWGs as well as finite PWWGs with arbitrary post positioning. Quite recently, we introduced an alternative approach for dealing with complex propagation constants, so that PWWG losses, and the scattering matrices of PWWG sections can be computed. These sections are represented by ‘current matrices’ that relate the ‘incoming’ electric and magnetic surface currents on predefined ports to the ‘outgoing’ surface currents. The derivation of the current matrices is based on Lorentzs reciprocity and Loves equivalence theorems. Both the ‘incoming’ and ‘outgoing’ surface currents are represented by rooftop bases. The scattering parameters of a PWWG section are determined by expressing waveguide modes in terms of these bases. Finally, the corresponding software code can be integrated in a circuit simulator, a familiar platform for microwave designers.