Citation
Caloyannides, Michael Akylas (1972) A mathematical and experimental investigation of microcycle spectral estimates of semiconductor flicker noise. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/MDV9W982. https://resolver.caltech.edu/CaltechTHESIS:04042016152719186
Abstract
The experimental portion of this thesis tries to estimate the density of the power spectrum of very low frequency semiconductor noise, from 10^{6.3} cps to 1. cps with a greater accuracy than that achieved in previous similar attempts: it is concluded that the spectrum is 1/f^{α} with α approximately 1.3 over most of the frequency range, but appearing to have a value of about 1 in the lowest decade. The noise sources are, among others, the first stage circuits of a grounded input silicon epitaxial operational amplifier. This thesis also investigates a peculiar form of stationarity which seems to distinguish flicker noise from other semiconductor noise.
In order to decrease by an order of magnitude the pernicious effects of temperature drifts, semiconductor "aging", and possible mechanical failures associated with prolonged periods of data taking, 10 independent noise sources were timemultiplexed and their spectral estimates were subsequently averaged. If the sources have similar spectra, it is demonstrated that this reduces the necessary datataking time by a factor of 10 for a given accuracy.
In view of the measured high temperature sensitivity of the noise sources, it was necessary to combine the passive attenuation of a specialmaterial container with active control. The noise sources were placed in a copperepoxy container of high heat capacity and medium heat conductivity, and that container was immersed in a temperature controlled circulating ethyleneglycol bath.
Other spectra of interest, estimated from data taken concurrently with the semiconductor noise data were the spectra of the bath's controlled temperature, the semiconductor surface temperature, and the power supply voltage amplitude fluctuations. A brief description of the equipment constructed to obtain the aforementioned data is included.
The analytical portion of this work is concerned with the following questions: what is the best final spectral density estimate given 10 statistically independent ones of varying quality and magnitude? How can the Blackman and Tukey algorithm which is used for spectral estimation in this work be improved upon? How can nonequidistant sampling reduce data processing cost? Should one try to remove common trands shared by supposedly statistically independent noise sources and, if so, what are the mathematical difficulties involved? What is a physically plausible mathematical model that can account for flicker noise and what are the mathematical implications on its statistical properties? Finally, the variance of the spectral estimate obtained through the Blackman/Tukey algorithm is analyzed in greater detail; the variance is shown to diverge for α ≥ 1 in an assumed power spectrum of k/f^{α}, unless the assumed spectrum is "truncated".
Item Type:  Thesis (Dissertation (Ph.D.))  

Subject Keywords:  Electrical Engineering  
Degree Grantor:  California Institute of Technology  
Division:  Engineering and Applied Science  
Major Option:  Electrical Engineering  
Thesis Availability:  Public (worldwide access)  
Research Advisor(s): 
 
Thesis Committee: 
 
Defense Date:  6 July 1971  
Funders: 
 
Record Number:  CaltechTHESIS:04042016152719186  
Persistent URL:  https://resolver.caltech.edu/CaltechTHESIS:04042016152719186  
DOI:  10.7907/MDV9W982  
Default Usage Policy:  No commercial reproduction, distribution, display or performance rights in this work are provided.  
ID Code:  9649  
Collection:  CaltechTHESIS  
Deposited By:  INVALID USER  
Deposited On:  06 Apr 2016 15:29  
Last Modified:  09 Nov 2022 19:20 
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