| Nowadays, there is a great demand for wireless communication systems with ultra-high data rates and multimedia with higher bandwidth. Ultra-Wide Band (UWB) and 60 GHz technology have become the representation of the fourth generation of wireless communication standards (4G) due to their ultra-high data rates (the former is 480 MHz, the later is up to several GHz), which has inspired the research upsurge in both industry and academy. At the same time, the move towards higher frequencies,higher data rates and wider band system has stimulated the development of both integration techniques and substrate materials for millimeter (mm)-wave applications. Therefore, it is urgent affairs to develop a new substrate technology with excellent performance and meeting various demands. Identified as advanced candidate materials for flexible mm-wave substrates'purposes and due to a unique combination of superior features and performance, Liquid Crystal Polymers (LCPs) have attracted considerable attention in commercial wireless applications. Like other materials, LCPs also show some disadvantages such as poor adhesion to Copper (Cu), problems in via processing, etc.In order to evaluate LCP's electrical performance, the design, fabrication and characterization of passive components operating at frequencies extending into the mm-wave regime are performed to determine the feasibility of LCP as a low-cost and high-performance substrate solution for mm-wave application. In this thesis, combining UWB and 60 GHz technology, a novel compact microstrip UWB bandpass filter, an UWB printed monopole antenna and two 60 GHz bandpass filters are presented on LCP substrates. The main contents of the dissertation include the following four parts:Firstly, LCP substrate combined/laminated with Copper (Cu) is prepared in order to improve the surface roughness of the LCP substrate, and the surface is pre-treated by means of oxygen plasma etching. In addition, a thin adhesion layer of Titanium (Ti) is applied prior to the sputter deposition of Cu to improve the adhesion between the Cu and the LCP material.Secondly, based on the dual-mode ring resonator theory, an UWB bandpass filters, working on 22 GHz～29 GHz is proposed. The proposed UWB bandpass filter includes a full dual-mode rectangular-ring resonator at the center, which controls the bandwidth of the passband and two novel parallel-coupled feed structures between input/output ports and the ring resonator, for coupling purposes with the resonator. The designed filter is compact, low-loss, easy to fabricate, and exhibits sharp attenuations and wide-stopbands, which can be used in vehicular radar systems.Thirdly, two 60 GHz bandpass filters are reported on LCP substrates, one is a planar microstrip bandpass filter with ultra-fine conductor linewidth and gap, which could work on 57 GHz～64 GHz band based on the parallel-coupled line structure, another one is wideband bandpass filter working on 50 GHz～70 GHz band based on dual-mode ring resonator structure.Finally, a hollowed UWB printed monopole antenna is also presented on a LCP substrate. It consists of a hollowed elliptical monopole, two trapeziform ground planes and a tapered CPW (Co-Planar Waveguide) feeder, which provides this antenna extremely wide bandwidth and compact size.By using standard processing methods i.e. surface pretreatment, sputter deposition, photolithography and wet etching, all of these microwave passive devices are fabricated on both laminated and direct metalized LCP substrates. The comparison of simulated and measured results of both developed filters and antennas is also shown and discussed. The fact that both filters and antennas on the direct metalized LCP substrates show good results, verifies that LCP materials are potentially promising substrate material for microwave/mm-wave applications.
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