This thesis is mainly composed of two parts. The first part is to introduce the planar transformer-based circuits and their applications. The mixed-mode S parameters and the grounding effects for planar transformers are discussed. A physical model has been developed for modeling the planar transformers. In the second part, a new coil winding technique for planar transformers has been presented to realize a high-efficiency planar transformer with arbitrary turn ratio for power-split/combine and phase-shift applications. Especially, the power-split/combine architecture based on a planar transformer of cellular shape is first presented in this thesis, enabling various kinds of passive components to be widely realized using the integrated passive device processes. As an example, this thesis proposes a design procedure for high-efficiency balun component. Firstly, design a high Q transformer that considers the load impedance effects. Secondly, design the ground reference for un-balanced signal on the virtual ground symmetry axis for balanced signals. Thirdly, design impedance matching networks for minimizing un-balanced and balanced port return losses. Then, a high performance planar transformer-based balun design can be done.

In this thesis, the study focuses on the antenna design for integrated passive devices. By using the substrate of piezoelectric material with high permittivity and introducing the fractal structures, the size reduction is obtained. Part of the research analyzes the influences of the surrounding environment on the antenna performances, including the effects of external formations, internal components, and interconnections. The results can provide the design rules for developing IPD antennas. The other part of the research emphasizes the design of IPD antenna itself, involving the investigations on the characteristics of substrate and fractals. The trade-off between compactness and radiation efficiency is pointed out, and then a design of modified ground plane is presented. When the modified design is placed on the system ground plane that exists in real system, the radiation efficiency can be improved significantly. Therefore, the concept of the compact IPD antenna is achieved.

This thesis realizes miniature bandpass filters using integrated passive device technology. The bandpass filters are designed based on coupled resonator method with single-band and dual-band responses, using a transformer structure with high-density winging pattern. In addition, the designs adopt the electric- and magnetic-field cancellation and the feedback mechanism to produce transmission zeros in the filter responses for enhancing selectivity and stopband rejection. In order to satisfy the specific requirements of commercial bandpass filter products, this thesis designed and implemented a trisection filter with cross coupling on a low-loss RT/Duroid substrate to generate a transmission zero very near the passband.

This dissertation aims to design and implement wireless passive components using domestic integrated passive device (IPD) technology. The research focuses on exploiting novel 3-D structures for various kinds of IPD-based wireless passive components including high-quality and high-efficiency planar transformers, baluns, filters, and combiners to achieve miniature size and high performance. A physical model has been developed for modeling the planar transformers. In this dissertation, a scalable transformer model in integrated passive device technology is further used to correlate with the coupled-line sections of a conventional Marchand balun. This improves the efficiency of the design of planar transformers with equivalent coupled-line parameters such as the coupling factor, and even- and odd-mode characteristic impedances and quality factors. Additionally, the proposed model-based design approach provides effective optimization techniques that incorporate geometrical and material parameters. In addition, a compact transformer-based coupled balun bandpass filter design is proposed based on integrated circuit technology and the equivalent circuit is established. Using a planar transformer with high-density fully symmetrical wiring not only greatly reduces the component size but also provides a superior stopband rejection and selectivity. Finally, by using the spiral-shaped resonators, the dual-band third-order bandpass filter has been implemented on organic substrates. The proposed BPF design is verified to overcome the elements¡¦ parasitic effects, and thus can be miniaturized and optimized with high degree of freedom. The simulation and measurement results have good agreement for the proposed design in this dissertation.