Investigations on Low Activation RF MEMS Shunt Switches (Record no. 116913)
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| 000 -LEADER | |
|---|---|
| fixed length control field | 05823ngm a22001577a 4500 |
| 008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION | |
| fixed length control field | 190518b ||||| |||| 00| 0 eng d |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | TT000081 |
| Item number | BHA |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Bhatasana, Piyushkumar Maganlal |
| 245 ## - TITLE STATEMENT | |
| Title | Investigations on Low Activation RF MEMS Shunt Switches |
| Statement of responsibility, etc | by Piyushkumar Maganlal Bhatasana |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Place of publication, distribution, etc | Ahmedabad |
| Name of publisher, distributor, etc | Nirma Institute of Technology |
| Date of publication, distribution, etc | 2018 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 157p Ph. D. Thesis with Synopsis and CD |
| 500 ## - GENERAL NOTE | |
| General note | Guided by: Dr. Dhaval Pujara With Synopsis and CD <br/>11EXTPHDE68 <br/><br/>ABSTRACT:<br/>Over the last decade, Radio Frequency (RF) Micro-Electro Mechanical System<br/>(MEMS) switches have replaced the conventional solid-state switches. The RF MEMS<br/>switches are found useful in many practical applications including wireless<br/>communications devices, reconfigurable antennas, software-defined radios, etc. In<br/>fact, the performance of such switches has improved over the years in terms of<br/>switching speed, isolation, power dissipation, requirement of activation voltage and<br/>reliability.<br/>There are many ways to classify the RF M`EMS switches. Based on the type of<br/>actuation, there are electrostatic, electromagnetic, piezoelectric and thermal types of<br/>switches. Out of these options, the electrostatic actuation is more preferred because of<br/>its advantages like low power consumption, fast switching and compatibility with<br/>electronic circuits. However, MEMS switches with electrostatic actuation require<br/>relatively high actuation voltage to activate the movable parts. This constraint makes<br/>the use of such switches limited for many practical applications, where low activation<br/>voltage is an essential requirement.<br/>This thesis focusses on investigations on the electrostatically actuated Micro-Electro<br/>Mechanical System (MEMS) capacitive shunt switches with emphasis on low<br/>activation voltage. The work is focused onthe designs of different RF MEMS shunt<br/>switches with low activation voltage. For all the proposed designs, the simulated<br/>results using standard design tools are obtained and verified with analytical results and<br/>are found to be in close agreement.<br/>The first proposed RF MEMS switch is composed of Pi(Π)-type piezoelectric<br/>cantilever, a coplanar wave transmission line (CPW) and contact electrodes. For the<br/>said design,the simulation and analytical results have been obtained. The performance<br/>of the Pi(Π)-type RF MEMS switch under different locations of bridges is discussed. For a 400 μm separation between two bridges and various bridge widths (25-75 μm),<br/>the switch provides better frequency over the range of 51-75.5 GHz. At 250 μm<br/>separation between the bridges with the same bridge width, the Pi(Π)-type RF MEMS<br/>switch operates on the frequency range of about 31.3-56.5 GHz. The activation voltage<br/>is found to be about 24 V for a 3μm initial bridge air gap of the RF MEMS switch.<br/>The RF MEMS switch takes almost the same time to settle at up-state condition even<br/>if the time in down-state position varies.<br/>Another RF MEMS switch has serpentinetype bridge structure. This type of bridge<br/>structure offers more flexibility to the bridge and results in low spring constant and<br/>less activation voltage requirement. The performance of the serpentine RF MEMS<br/>switch with various designs of bridge arms is discussed for the same overlap area<br/>between the signal line and the bridge. The electrostatic results are discussed from flat<br/>to serpentine bridge arms. The activation voltage as low as 10.75 V with 1 μm<br/>thickness and 200 μm long bridge is obtained for the serpentine bridge RF MEMS<br/>switch. The bandwidth of the switch isachieved in the range of 21.3-50 GHz with a 30<br/>μm signal line width and 90 μm bridge width.<br/>The third important design is a Crag-lagshaped RF MEMS switch with low spring<br/>constant and low activation voltage of the order of 4.7 V. Among all the designs of RF<br/>MEMS switch presented in the thesis, the Crag-lag bridge structure is more flexible<br/>with higher mechanical strength. In this design, there are two actuation electrodes and<br/>a separate signal line. Both electrodes and a signal line are arranged such that the<br/>whole arrangement isolates the DC static charge and the input operating signal. The<br/>switch operates on 4.7 V of activation voltage for a 3 μm bridge height, 5 μm × 5 μm<br/>vias, 95 μm × 205 μm actuation electrodes. This quantum of operating voltage can be<br/>compatible with CMOS operating voltage for on-chip fabrication. The return-loss in<br/>the up-state condition and the isolation in the down-state condition are found better<br/>than -20 dB over a wide frequency band of 14-41 GHz. The same switch yields<br/>insertion loss in up-state and return-loss in down-state condition lower than 0.5 dB<br/>over the same frequency band. Apart from switch designs, a phase shifter with a flat bridge type of RF MEMS switch<br/>is also designed and simulated. Nine flat bridges are connected in parallel on top of the<br/>signal line. Each bridge provides some phase shift depending upon the capacitance<br/>between the bridge and the signal line. The phase shifter provides phase shift of 45°,<br/>60°, 90°, and 180° at actuation voltage of 6.5 V, 7 V, 10 V and 10.7 V, respectively, for<br/>40 GHz of operating frequency.<br/>Based on the results of the designed RF MEMS switches and phase shifter, it is<br/>believed that all the proposed RF MEMS switches can operate in X to Ka bands.<br/>Moreover, it is possible to achieve excellent isolation and insertion loss properties<br/>using proposed RF MEMS switches. The proposed RF MEMS switches are suitable<br/>for use in various high frequency applications. |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Uniform Resource Identifier | http://repository.nirmauni.ac.in/jspui/handle/123456789/8388 |
| Public note | Institute Repository (Campus Access) |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Uniform Resource Identifier | http://shodhganga.inflibnet.ac.in/handle/10603/299431 |
| Public note | Shodhganga |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Source of classification or shelving scheme | Dewey Decimal Classification |
| Koha item type | Thesis |
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