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Revision of the author's Thesis (M.A.)--University of Texas, 1990. / Includes bibliographical references (p. 79-84) and index.

Chemnitz, Techn. Univ., [Studienarb.], 2004.

MEMS based mechanical switches are seen to be the likely replacements for CMOS based switches due to the several advantages that these mechanical switches have over CMOS switches. Mechanical switches can be used in systems under extreme conditions and also provide more reliability and cause less power loss. A major problem with mechanical switches is bouncing. Bouncing is an undesirable characteristic which increases the switching time and causes damage to the switch structure affecting the overall switch life. This thesis proposes a new switch design that may be used to mitigate bouncing by using two voltage sources using a double electrode configuration. The effect of many switch’s tunable parameters is also discussed and an effective tuning technique is also provided. The results are compared to the current control schemes in literature and show that the double electrode scheme is a viable control option.

The need for low cost and low size radiometers have encouraged many to look at the implementation of radiometers using MMICs. Compared to their waveguide counterparts, radiometers implemented with MMICs significantly reduce the size and weight of the radiometer, while still maintaining satisfactory electrical performance at millimeter wave frequencies. Utilizing MMICs can also help in significantly lowering the noise temperature of the radiometer, specifically, metamorphic high electron-mobility transistors (mHEMT) have demonstrated very low noise, high gain performance and comparably low cost. This thesis is focused on designing a combined switch and low noise amplifier IC at 36.5 GHz that lowers the radiometer noise temperature while allowing for an accurate calibration. The measured gain from straight and 90 degree input of the switch-LNA, at 36.5 GHz, was 6.6 dB and 7.1 dB, respectively. Likewise, the noise figure of the MMIC was 3.8 dB and 3.3 dB, respectively. The mHEMT implemented SPDT switch has a measured insertion loss, at 36.5 GHz, of 1.3 dB and 0.88 dB with isolation of 25 dB and 36 dB, respectively. The calculated temperature sensitivity based on measured temperature variations was 0.273 K at 36 GHz.

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The speed and simplicity of the metal-semiconductor-metal (MSM) detector has made it a prime candidate for use in integrated optoelectronic circuits. While in most applications the optical input is coupled in through the top surface of the device, it is also possible to distribute the optical signal by means of transparent waveguides that are located below the absorbing detector layer. By controlling the degree of coupling between the waveguide and detector layers the detectors can be made to act as optical taps. The optical signal can thus be shared among a series of detectors as required in optoelectronic switching applications. We have made a series of simple ridge waveguides, each with a number of MSM structures designed for the characterization of absorption, responsivity and frequency response. A 4x4 optoelectronic switch was also fabricated and analyzed. We show that balancing the switch is accomplished by tailoring the absorption coefficient in the detector region so that all detectors absorb equal amounts of optical power. / Thesis / Master of Engineering (ME)

The speed and simplicity of the metal-semiconductor-metal (MSM) detector has made it a prime candidate for use in integrated optoelectronic circuits. While in most applications the optical input is coupled in through the top surface of the device, it is also possible to distribute the optical signal by means of transparent waveguides that are located below the absorbing detector layer. By controlling the degree of coupling between the waveguide and detector layers the detectors can be made to act as optical taps. The optical signal can thus be shared among a series of detectors as required in optoelectronic switching applications. We have made a series of simple ridge waveguides, each with a number of MSM structures designed for the characterization of absorption, responsivity and frequency response. A 4x4 optoelectronic switch was also fabricated and analyzed. We show that balancing the switch is accomplished by tailoring the absorption coefficient in the detector region so that all detectors absorb equal amounts of optical power. / Thesis / Master of Engineering (ME)