Multi-port RF MEMS switches and switch matrices

Microwave switch matrices are essential components in satellite payloads. These matrices enhance satellite capacity by providing full and flexible interconnectivity between the received and transmitted signals and facilitate optimum utilization of system bandwidth. Waveguide and semiconductor technology are two prominent candidates for realizing such types of switch matrices. Waveguide switches are dominant in high frequency applications (100--200 GHz) and in high power satellite communication. However, their heavy and bulky profile reinforces the need for a replacement. While, semiconductor switches are miniature alternatives to mechanical waveguide switches, they exhibit poor RF performance and low power handling.; RF MEMS technology is a good candidate to replace the conventional switches. The technology has a great potential to offer highly miniature switches with superior RF performance. Over the past five years, numerous research studies have been devoted to develop RF MEMS switches. However, they are mostly concentrated on Single-Pole Single-Throw (SPST) configurations and a very limited work has been reported on multi-port switches and switch matrices. Hence, the focus of this thesis is on the development of multi-port RF MEMS switches and switch matrices. To explore the topic, three development tasks are considered: planar (2D) multi-port RF MEMS switches, three dimensional (3D) multi-port RF MEMS switches, and RF MEMS switch matrix integration.; One key objective of this thesis is to investigate novel configurations for planar multi-port (SPNT), C-type, and R-type switches. Such switches represent the basic building blocks of switch matrices operating at microwave frequencies. Theoretical and experimental results are presented for the proposed novel multi-port switch configurations. In addition, an in house monolithic fabrication process dedicated to electrostatic multi-port RF MEMS switches is developed and fine tuned.; For the first time, a new category of 3D RF MEMS switches is introduced to the RF MEMS community. These switches are not only extremely useful for high power applications but also have a great potential for millimetre-wave applications (30GHz--1000Hz). The idea is based on the integration of vertically actuated MEMS actuators inside 3D transmission lines such as waveguides and coaxial lines. SPST and C-type switches based on the integration of rotary thermal and electrostatic actuators are designed and realized. The concept is experimentally verified for frequencies up to 30GHz. A high power test analysis and measurement data indicates no major change in RF performance as high as 13W.; The monolithic integration of the RF MEMS switch matrix involves the design and optimization of a unique interconnect network which is amenable to the MEMS fabrication process. While the switches and interconnect lines are fabricated on the front side, taking advantage of the back side patterning provides a high isolation for cross over junctions. Two different techniques are adopted to optimize the interconnect network. They are based on vertical three-via interconnects and electromagnetically coupled junctions. The measured results demonstrate that the monolithic switch matrix exhibits an isolation of better than 40dB up to 30GHz. This technique not only eliminates the need for expensive multilayer manufacturing process such as Low Temperature Co-fired Ceramics (LTCC) but also provides a unique approach to fabricate the entire switch matrix monolithically.