Abstract The thesis describes the development of a novel LTCC material system for RF and microwave telecommunication purposes. The work has been divided into three parts. In the first section, the compositional and firing properties of this novel LTCC dielectric have been studied as well as its thermomechanical and dielectric properties. The second section describes the multilayer component preparation procedure for the ceramic material including tape casting and lamination parameters and the selection of the conductor paste. In the last section, the novel LTCC material system has been used to demonstrate its properties in RF multilayer resonators and a bandpass filter. The dielectric material for the novel LTCC system was prepared using magnesium calcium titanate ceramic, the firing temperature of which was decreased to 900°C by the addition of a mixture of zinc oxide, silicon oxide and boron oxide. The powder was made without any prior glass preparation, which is an important process advantage of this composition. The fired microstructure was totally crystalline with high density (3.7 Mg m-3) and low porosity (0.5 %). The mechanical properties were virtually identical to the values of the commercial LTCCs, but the higher thermal expansivity makes it most compatible with alumina substrates. The dielectric values were also good. The permittivity was 8.5 and the dissipation factor (0.9·10-3 at 8 GHz) less than that of the commercial LTCCs. Furthermore, the temperature coefficient of the resonance frequency was demonstrated to be adjustable between the range of +8.8 ... -62 ppm/K with a simple compositional variation of titanium oxide. The slurry for the tape casting was prepared using poly(vinyl butyral) -base organic additives and the 110 μm thick tapes had a smooth surface (RA < 0.5 μm). The multilayer components were prepared using 20 MPa lamination pressure, 90°C temperature and 1 h dwell time. The most suitable conductor paste for this composition was found to be commercial silver paste (duPont 6160), which produced satisfactory inner and outer conductor patterns for multilayer components. Finally, resonators with a resonant frequency range of 1.7 ... 3.7 GHz were prepared together with a bandpass filter suitable for the next generation of telecommunication devices. This demonstration showed the potential of the developed novel LTCC material system at high RF frequencies.

<p>Tematika disertacije obuhvata projektovanje, izradu i karakterizaciju pasivnih induktivnih RF komponenti u PCB i LTCC tehnologiji, kao i poboljšanje njihovih performansi. Izvršena je i karakterizacijarazličitih tipova dielektričnih i feritnih&nbsp; LTCC materijala koji su korišćeni za izradu komponenti. Ukupno je projektovano i izrađeno 37 struktura, 14 induktora i 23 transformatora. Na poboljšanje karakteristika projektovanih struktura, koje se ogleda prvenstveno u povećanju induktivnosti zavojaka, uticalo se izradom projektovanih struktura na supstratima izrađenih od različitih materijala, supstratima formiranih od kombinacije materijala različitih karakteristika, redizajnom osnovnih (polaznih) geometrija struktura i optimizcijom parametara LTCC postupka izrade.</p> / <p>Topic of this theases focuses on design, fabrication and characterization of industive passive RF components in PCB and LTCC technology, as well as on improvement of their performances. Characterization of different types ofdielectric and ferrite LTCC materials that were implemented for component fabrication was also performed. In total, 37 structures were designed and fabricated, of those 14 are inductor structures and 23 are transformers. Performance improvement of designed structures that is manifested through increase of inductance value of structures windings implied fabrication of designed components on substrates formed from different materials, or from combination of two or more materials with different properties, redesign of original design and optimization of LTCC fabrication process parameters.</p>