Low frequency sinusoidal oscillator for impedance spectroscopy
| dc.contributor.advisor | Viswanathan, T. R., doctor of electrical engineering | |
| dc.creator | Revanna, Nagaraja | en |
| dc.date.accessioned | 2014-07-22T20:01:13Z | en |
| dc.date.issued | 2014-05 | en |
| dc.date.submitted | May 2014 | en |
| dc.date.updated | 2014-07-22T20:01:14Z | en |
| dc.description | text | en |
| dc.description.abstract | Impedance measurement as a function of frequency is being increasingly used for the detection of organic molecules. The main building block required for this is a sinusoidal oscillator whose frequency can be varied in the range of a few KHz to tens of MHz. The thesis describes the design of Integrated CMOS Oscillator Circuits. There are 2 designs presented in the thesis, one of which is based on the Wien Bridge and the other, on an LC architecture. They provide both in-phase and quadrature outputs needed for the determination of the real and imaginary parts of complex impedances. The inductor in the LC tank is realized by gyration of a capacitor. This needs two variable transconductance elements. Linear transconductance elements with decoupled transconductance gm and output conductance go is presented. A novel circuit for detecting and controlling the amplitude of oscillation is described. A current mode technique to scale the capacitance is also discussed. Since this oscillator is used in an inexpensive hand-held instrument, both power consumption and chip area must be minimized. A comparison between the Wien Bridge and the LC tank based oscillator is presented. Simulation results pertaining to the design of the different blocks of the circuit are made available. | en |
| dc.description.department | Electrical and Computer Engineering | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.uri | http://hdl.handle.net/2152/25263 | en |
| dc.language.iso | en | en |
| dc.subject | Gyrator | en |
| dc.subject | Impedance spectroscopy | en |
| dc.subject | Integrated oscillators | en |
| dc.subject | Inverter-based linear variable transconductance | en |
| dc.subject | LC oscillator | en |
| dc.subject | Oscillators with quadrature output | en |
| dc.subject | Sinusoidal oscillators | en |
| dc.subject | Wien Bridge | en |
| dc.title | Low frequency sinusoidal oscillator for impedance spectroscopy | en |
| dc.type | Thesis | en |
| thesis.degree.department | Electrical and Computer Engineering | en |
| thesis.degree.discipline | Electrical and Computer Engineering | en |
| thesis.degree.grantor | The University of Texas at Austin | en |
| thesis.degree.level | Masters | en |
| thesis.degree.name | Master of Science in Engineering | en |