Design and fabrication of rf mems switches and instrumentation for performance evaluation

Atasoy, Halil İbrahim
This thesis presents the RF and mechanical design of a metal-to-metal contact RF MEMS switch. Metal-to-metal contact RF MEMS switches are especially preferred in low frequency bands where capacitive switches suffer from isolation due to the limited reactance. Frequency band of operation of the designed switch is from DC to beyond X-band. Measured insertion loss of the structure is less than 0.2 dB, return loss is better than 30 dB, and isolation is better than 20 dB up to 20 GHz. Isolation is greater than 25 dB below 10 GHz. Hence, for wideband applications, this switch offers very low loss and high isolation. Time domain measurement is necessary for the investigation of the dynamic behavior of the devices, determination of the ‘pull in’ and ‘pull out’ voltages of the membranes, switching time and power handling of the devices. Also, failure and degradation of the switches can be monitored using the time domain setup. For these purposes a time domain setup is constructed. Moreover, failure mechanisms of the RF MEMS devices are investigated and a power electronic circuitry is constructed for the biasing of RF MEMS switches. Advantage of the biasing circuitry over the direct DC biasing is the multi-shape, high voltage output waveform capability. Lifetimes of the RF MEMS devices are investigated under different bias configurations. Finally, for measurement of complicated RF MEMS structures composed of large number of switches, a bias waveform distribution network is constructed where conventional systems are not adequate because of the high voltage levels. By this way, the necessary instrumentation is completed for controlling a large scale RF MEMS system.


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This thesis presents development of microwave lumped elements for a specific surface-micromachining based technology, a self-contained mechanical characterization of fixed-fixed type beams and realization of a shunt, capacitive-contact RF MEMS switch for millimeter-wave applications. Interdigital capacitor, planar spiral inductor and microstrip patch lumped elements developed in this thesis are tailored for a surface-micromachining technology incorporating a single metallization layer, which allows an easy ...
Novel impedance tuner, phase shifter, and vector modulators using rf mems technology
Ünlü, Mehmet; Demir, Şimşek; Department of Electrical and Electronics Engineering (2009)
This thesis presents the theory, design, fabrication, and measurement results of novel reconfigurable impedance tuner, phase shifter, and vector modulators using the RF MEMS technology. The presented circuits are based on triple stub topology, and it is shown both theoretically and experimentally in this thesis that it is possible to control the insertion phase and amplitude of the input signal simultaneously using this topology. The presented circuits are implemented using an in-house, surface micromachini...
Advanced readout and control electronics for mems gyroscopes
Temiz, Yüksel; Akın, Tayfun; Department of Electrical and Electronics Engineering (2007)
This thesis reports the development of advanced readout and control electronics for MEMS gyroscopes developed at METU. These gyroscope electronics are separated into three main groups: high sensitive interface circuits, drive mode amplitude controlled self oscillation loops, and sense mode phase sensitive amplitude demodulators. The proposed circuits are first implemented with discrete components, and then integrated on CMOS chips. A self oscillation loop enabling constant amplitude drive mode vibrations in...
Analysis, design, and implementation of a 5 kw zero voltage switching phase-shifted full-bridge DC/DC converter based power supply for arc welding machines
Uslu, Mutlu; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2006)
Modern arc welding machines utilize controllable high frequency DC/DC power supply with high dynamic and steady state current regulation performance. In the design robustness, small size and low weight, low complexity, and high efficiency are the defining criteria. The most suitable approach for a 5 kW arc welding machine power supply application is the high frequency Full-Bridge Phase-Shifted Zero Voltage Switching (FB-PS-ZVS) DC/DC converter with an isolation transformer. This converter not only gives the...
Design of boost converter for educational test bench
Öztürk, Orhan; Üçtuğ, Yıldırım; Department of Electrical and Electronics Engineering (2006)
In this thesis a boost converter is developed to be used as a test bench in power electronics laboratory. For this purpose, first, steady-state and small-signal analyses of a boost converter are carried out, then closed loop control of the converter is developed and simulated. Then, the circuit is designed and manufactured. The test results are compared with the simulation results. Finally, an experimantal procedure is prepared to enable the students to perform the experiment in the laboratory with the test...
Citation Formats
H. İ. Atasoy, “Design and fabrication of rf mems switches and instrumentation for performance evaluation,” M.S. - Master of Science, Middle East Technical University, 2007.