Design of an X-band 3-bit RF MEMS constant phase shifter

Download
index.pdf
2016
Kuzubaşlı, Ahmet
Show full item record
0
views
0
downloads
This thesis presents a 3-bit 180° constant phase shifter design implementing Co-Planar Waveguide (CPW) and RF MEMS variable capacitors with ±1.8% accuracy at 10 GHz and ±5.8% maximum peak error between 9-11 GHz. The phase shifter with minimum phase errors is determined by considering exemplary circuit simulations of different phase shifter types designed with a novel in-house RF MEMS fabrication process [1] parameters. Due to its wide-band characteristics and CPW compatibility, the selected topology is the reflect-type phase shifter employing RF MEMS capacitor banks and 3-dB couplers. Phase shifts are provided by the change in the reflection phase of RF MEMS capacitor banks. At first, a 2-bit 90° phase shifter is designed to cover 0°-90° phase shifts. Successive addition of two 2-bit phase shifters allows to obtain a 3-bit operation up to 180° phase shift. The capacitor bank design includes various configurations of RF MEMS capacitors, and they are compared to provide minimum phase errors between 9-11 GHz. The design procedure is managed while having regard to the in-house novel RF MEMS fabrication technique [1] and its design rules. Two different options are considered for the design of 3-dB couplers, namely regular Branch-Line Coupler (BLC) and Double Branch-Line Coupler (DBLC), comparing their bandwidths which are defined by phase difference and power imbalance between coupled and thru ports. Circuit simulations suggest to use a miniaturized double branch-line coupler (M-DLBC) implementing CPW Lines shortened with lumped air-bridge capacitors, and therefore this coupler and RF MEMS capacitor banks are modelled and simulated by using a 3D Electromagnetic (EM) solver software. The proposed 3-bit phase shifter provides phase shifts with a ±1.8% accuracy at 10 GHz and ±5.8% maximum peak error between 9-11 GHz. The mechanical parameters such as spring constant and pull-in voltages of RF MEMS bridges used in the phase shifter are also calculated.
Microelectromechanical systems., Radio frequency microelectromechanical systems.
http://etd.lib.metu.edu.tr/upload/12619784/index.pdf
https://hdl.handle.net/11511/25469
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Design and prototyping of an electromagnetic mems energy harvester for low frequency vibrations
Türkyılmaz, Serol; Külah, Haluk; Department of Electrical and Electronics Engineering (2011)
This thesis study presents the design, simulation, and fabrication of a low frequency electromagnetic micro power generator. This power generator can effectively harvest energy from low frequency external vibrations (1-100 Hz). The main objective of the study is to increase the efficiency of the previously proposed structure in METU-MEMS Center, which uses the frequency up-conversion technique to harvest energy from low frequency vibration. The proposed structure has been demonstrated by constructing severa...
Cantilever type radio frequency microelectromechanical systems shunt capacitive switch design and fabrication
Demirel, Kaan; Yazgan, Erdem; Demir, Şimşek; Akın, Tayfun (SPIE-Intl Soc Optical Eng, 2015-9-21)
A new cantilever type radio frequency microelectromechanical systems (RF MEMS) shunt capacitive switch design and fabrication is presented. The mechanical, electromechanical, and electromagnetic designs are carried out to get <40 V actuation voltage, high isolation, and low insertion loss for 24 and 35 GHz and the fabrication is carried out for 24 GHz RF MEMS switch. The fabricated switch shows lower than 0.35 dB insertion loss up to 40 GHz and greater than 20 dB isolation at 22 to 29 GHz frequency band. An...
Design of a MEMS based hydraulic pressure sensor
Göreke, Utku; Azgın, Kıvanç; Beyaz, Mustafa İlker; Department of Micro and Nanotechnology (2016)
This dissertation presents a novel technique for detection of hydraulic pressure by using a MEMS resonant sensor. Proposed sensor utilizes a double ended tuning fork (DETF) resonator. In the literature tuning forks are used for measurement of the deflection of a diaphragm. However, in this study, a tuning fork is configured to lay in orthogonal direction with a diaphragm of which center point deflection is being measured. Upon application of pressure, center deflection of the diaphragm induces an axial comp...
Design and implementation of low leakage MEMS microvalves
Yıldırım, Ender; Külah, Haluk; Arıkan, Mehmet Ali Sahir; Department of Mechanical Engineering (2011)
This thesis presents analysis, design, implementation, and testing of electrostatically actuated MEMS microvalves. The microvalves are specifically designed for lab-on-a-chip applications to achieve leakage ratios below 0.1 at pressure levels in the order of 101 kPa. For this purpose, two different microvalves are presented in the study. In the proposed designs, electrostatic actuation scheme is utilized to operate the microvalves in normally open and normally closed modes. Characterization of normally open...
Frequency tunable microstrip patch antenna using RF MEMS technology
Erdıl, Emre; Topallı, Kagan; Unlu, Mehmet; Aydın Çivi, Hatice Özlem; Akın, Tayfun (2007-04-01)
A novel reconfigurable microstrip patch antenna is presented that is monolithically integrated with RF microelectromechanical systems (MEMS) capacitors for tuning the resonant frequency. Reconfigurability of the operating frequency of the microstrip patch antenna is achieved by loading it with a coplanar waveguide (CPW) stub on which variable MEMS capacitors are placed periodically. MEMS capacitors are implemented with surface micromachining technology, where a 1-mu m thick aluminum structural layer is plac...
Citation Formats
A. Kuzubaşlı, “Design of an X-band 3-bit RF MEMS constant phase shifter,” M.S. - Master of Science, Middle East Technical University, 2016.
METU IIS - Integrated Information Service open@metu.edu.tr