EXPERIMENTAL INVESTIGATIONS ON UNIFORM THIN FILM R-C-KR STRUCTURES

Abstract

Unifozm Olin film R-C4CR structures have superior attenuation and phase characteristics as cauparad to lumped networks,. A large amount of work has been done in the past several years on the fabrication of distributed structures based on Thin Film Tecbnology. This dissertation presents a canple a process of fabricating these structures by evaporating resistive (80,20 niche e) films on either side of a thin ( 150 crens) glass slide and aluminium uses on the extrne ends of each filmn.. various electrical measurements were carried out on the oanplete encapsulated stnactures to investigate their application as low pass and notch filters The value of resistance of niche rme film ranges from 17 ohms to 40 ohms, The value of capacitance for different structures ranges from 70 p.1. to 1650 p. f. The effect of resistive load on the per oxence of these filter are graphically displayed. it has beam found that the frequency response of these filters its independent of the i c resistance greater than the charsc' teristic impedance but it decreases with decrease of lead resistance for the values lower than characteristic impedance. Also, the lead has no effect en the cut off frequency of pass filter and notch frequency of the notch filter section,. in order to have a Cc T paratiVe study the theoretica3 characteristics as calculated* calculated phase shift in case of 1vtged RC amen is only 85 over this span %t a cutoff frequency at which the gain is 0.93 tin the pass band gain of distributed RC lew pass network ceinsides with that of lumped Rc netwoA for which gain at Cut off frequency is «707 times the pass band gain. this dsortaticn also includes a ccsnp3ete process of fabrication of Met su1.ator Resistive (PSZR) purely Thin fi2m structure by evaporating aluminium en a glass slide, anodizing a portion of alurninLizn layer for dielectric i3m and evaporating ntchr ne en the dieiectric film*, Ztis electrical measurements and stwcture behaviour could riot be studiedand have been left for future