Innovative microwave and millimetre-wave components and sub-systems based on substrate integration technology

The tendency of modern microwave and millimetre-wave communication system development is towards small size, light weight, reliable, multifunctional and low-cost. Moreover, low-cost, mass producible, high-performance and high-yield microwave and millimetre wave technologies are crucial for developing successful commercial microwave and millimetre wave systems. Rectangular waveguide has always been among the most popular choices for the making of millimetre-wave circuits and systems. A major challenge, however, is related to its integration with active devices and other conventional planar transmission lines, such as microstrip or coplanar waveguide (CPW), etc. Substrate Integrated Circuits (SICs) techniques including substrate integrated waveguide (SIW), which can be integrated in planar dielectric substrate with low insertion loss, high Q and low radiation loss, present a family of novel guided wave structures. This scheme provides a bridge between planar and non-planar structures. Up to now, microwave components and sub-systems based on SIW technology have been widely studied and developed.;In this thesis, we take a further study of SIW technology to propose and develop various innovative and original microwave and millimetre-wave passive and active components. These innovative component structures can improve the integration between SIW components and other planar components. Then, a certain number of proposed structures or components are applied in the design and demonstration of millimetre-wave integrated antenna arrays and 60 GHz smart antenna sub-system. Note that many components studied in this work were proposed and demonstrated at different lower microwave frequencies for the proof of concept purpose with easy-to-fabricate structures and circuits. Those low-frequency circuits can easily be scaled up for high-frequency applications.;In Chapter 1, three passive components such as magic-T, wideband filter and antenna are studied and developed. First, we propose a slotline-to-SIW transition which is investigated, leading to the development of 180° reverse-phase T junction and planar magic-Ts. Next, we take the advantage of high-pass characteristics of the half-mode substrate integrated waveguide (HMSIW) to realize a super wideband band-pass filter by cascading a section of HMSIW with a microstrip low-pass filter. Another wideband application of SICs concept is related to an antipodal linearly tapered slot antenna (ALSTA) structure fed by a substrate parallel plate waveguide as TEM mode transmission line.;In Chapter 2, we make use of SICs techniques in the design of PA, mixer and voltage controlled oscillator (VCO). First of all, planar tunable reflective SIW and HMSIW cavity resonators are developed. An X-band low phase noise VCO based on SIW tunable reflective cavity resonator has been developed and realized. Besides oscillator applications, SIW can also be applied to PA design. A multi-section SIW is investigated, and results show that any harmonics could be suppressed. As a practical and straightforward demonstration, an X-band singly balanced mixer using our proposed modified magic-T is designed and measured with good performances.;In Chapter 3, three kinds of integrated active antenna array are developed based on the SIW ALTSA in the work. First, an X-band spatial power amplifier is proposed and realized. Second, a Ka-band 2x2 up-converter antenna array which can be seen as a low-cost transmitter for millimetre-wave short distance communications. Finally, a Ka-band 1x4 rectenna array is introduced.;In the thesis, another major application of SICs as described in Chapter 4 is to develop a 60 GHz switched-beam receiver sub-system based on the above-discussed research results of the SIW technology. This is the first time to realize and demonstrate a 60 GHz beamforming receiver system employing 60 GHz front-end mainly using the SIW technology. This receiver makes use of an SIW 4x4 Butler matrix network and an SIW antenna to construct the sub-system. To decrease the cost of the sub-system, 30 GHz SIW LO sources and SIW sub-harmonically down-converter mixers are developed. As a result, IF signals obtained in the chain are processed within IF circuitry and a DSP core to extract controlled signals. Consequently, beam of the sub-system is adaptively switched by the controlled signals according to the criterion of maximum received signal. The thesis will be finally concluded with various remarks in connection with key concepts and original contributions presented in this work as well as discussions on future research and development on this SICs topic.