Wojciech Marynowski

Intramolecular interactions in crystals of tris(2,6-diisopropylphenoxy)silanethiol and its sodium salts.

Hydrolytically stable silanethiol tris(2,6-diisopropylphenoxy)silanethiol (TDST) has been synthesized and reacted with sodium metal. In solid state TDST exhibits π-interactions between the S-H unit and the π-system of the arene, replaced by cation-π interactions in its sodium salts. The interactions are documented by crystal structures and FT-IR spectroscopy.

An Analysis of Probe-Fed Rectangular Patch Antennas With Multilayer and Multipatch Configurations on Cylindrical Surfaces

A multipatch configuration of probe-fed rectangular microstrip antennas mounted on a cylindrical body, with electrically small radius, with an arbitrary number of substrate and superstrate layers is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. A unified procedure for creating proper matrices for the investigated geometry of the structure is outlined here. Numerical results for the input impedances and radiation patterns are calculated and verified by comparing them with results from the literature and our own measurements of manufactured prototypes.

STUDY OF NONRECIPROCAL DEVICES USING THREE- STRIP FERRITE COUPLED LINE

This paper presents the investigations of nonreciprocal devices employing a novel ferrite coupled line junction. The structure is designed using coplanar line technology with the ground half-planes reduced to the strips. The investigated junction is composed of one ferrite section placed in between of two dielectric sections. In the ferrite section the longitudinally magnetized ferrite slab is located at the top or the bottom of the strips and is covered with the dielectric layers. In the dielectric sections the ports of the junctions are located. The wave parameters and fleld distributions of the modes propagated in the dielectric and ferrite sections are obtained from spectral domain approach. In order to determine the scattering matrix of the junction the mode matching method is utilized. The investigation of the circulator and isolator designed based on the S- matrix of the junction are presented. The obtained results are verifled by comparing them with HFSS simulations and own measurements of the fabricated devices. In both cases a very good agreement is observed.

ON THE CHARACTERISTIC IMPEDANCE DEFINITION IN MICROSTRIP AND COPLANAR LINES

In this paper the deflnition of characteristic impedance for lossless microstrip and coplanar lines has been considered. It has been shown that due to a signiflcant value of the displacement current related to longitudinal component of the electric fleld, impedance deflnition becomes ambiguous. Such ambiguity can cause considerable errors in design procedure. This efiect is especially noticeable in the coplanar lines, in opposite to microstrip ones. To conflrm the validity of the applied algorithm (spectral domain approach) the propagation coe-cients and characteristic impedances have been compared to values obtained from commercial software.

An Analysis of Elliptical-Rectangular Multipatch Structure on Dielectric-Coated Confocal and Nonconfocal Elliptic Cylinders

A rigorous analysis of the resonance frequency problem of an elliptical-rectangular microstrip structure mounted on dielectric-coated elliptic conducting cylinder, with electrically small radius, is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. The complex resonance frequencies of the structure are studied. Modes suitable for antenna application are also investigated. Numerical results for the complex resonance frequency and radiation patterns are calculated and verified by comparing them with results from commercial software and our own measurements of manufactured prototypes. The difference between confocal and nonconfocal dielectric-coated elliptic cylinders is investigated.

Investigations of Cylindrical Ferrite Coupled Line Junction Using Hybrid Technique

In this paper, a novel longitudinally magnetized cylindrical ferrite coupled line (CFCL) junction is proposed. In comparison to planar ferrite coupled line (FCL) conflgurations, which are well known in literature, in such structure the higher gyromagnetic coupling occurs. This allows to obtain the required in FCL devices Faraday rotation angle …=4 for the ferrite with shorter length and lower value of magnetization. As a result the total insertion losses in the ferrite section can be reduced using the proposed topology. In the analysis of the proposed CFCL junction a hybrid technique combining method of moments and coupled mode method (MoM/CMM) is applied. The results are compared with the ones obtained from commercial software HFSS and a good agreement is obtained.

Microstrip Ferrite Coupled Line Isolators

The double isolators using sections of ferrite coupled microstrip lines are demonstrated in a layered and planar approaches. The configurations are investigated both theoretically and experimentally at the frequency range 8-15 GHz. The better performances are observed for planar configuration that reports reflection losses -15 dB, isolation better than -18 dB and average insertion losses about 3 dB.

Investigations of four-port circulator utilizing cylindrical ferrite coupled line junction

In this paper the numerical and experimental investiga- tions of four-port circulator utilizing longitudinally magnetized cylin- drical ferrite coupled lines (CFCL) section are presented for the flrst time. In comparison to earlier models the proposed structure of cir- culator utilizes multilayer magic-T junction cascaded with cylindri- cal ferrite section of …=4 Faraday angle. The advantage of utilization of cylindrical section over the planar one is the possibility to design shorter ferrite junctions ensuring lower insertion losses. Moreover, the multilayer magic T-junction allows to improve performance of the pro- posed circulator by omitting the bandwidth limitation which exists in commonly used hybrid couplers with air-bridges. In the analysis of CFCL junction the full wave hybrid approach combining flnite difier- ence frequency domain method with method of moments and mode matching technique is applied. The planar feeding structures of circu- lator are designed with the use of commercial software. The simulated results of the entire circulator are compared with the measurement results of the fabricated prototype and a good agreement is achieved.

Investigations of nonreciprocal devices employing cylindrical ferrite coupled line junction

This paper presents application of a novel cylindrical ferrite coupled line (CFCL) junction to integrated nonreciprocal devices. In such a junction, high gyromagnetic coupling occurs. This gives possibility to design a Faraday rotation CFCL junction with the ferrite rod having shorter length and lower saturation magnetization than the planar structures commonly known in literature. By utilizing the proposed cylindrical junction in integrated nonreciprocal devices, it is possible to reduce not only their dimensions but also the insertion losses occurring in such structures. In this paper, we present an application of CFCL junction to integrated isolator. The results of numerical simulations are verified experimentally, and good agreement is observed.

Investigations of the double isolator using three-strip ferrite coupled line

The double isolator using sections of the three-strip ferrite coupled line are presented. The device was developed in two different ways: as a cascade of two circulators and as a planar structure containing lumped resistor. The devices were investigated both theoretically and experimentally. In the experiment the integrated structure of planar double isolator produced average reflection losses better than −10dB in the band from 11 to 14GHz. The average insertion losses were about −4.5dB and isolation was better than −16dB.