发明名称 |
ELECTRONIC PHASE COMPARISON APPARATUS FOR THE REMOTE MEASUREMENT OF LAYER THICKNESS |
摘要 |
<p>A continuous wave, phase measurement system which provides at least an order of magnitude improvement in accuracy over modulated carrier systems is disclosed for the determination of the thicknesses of layered targets consisting of a known number of dielectric layers, each of a known maximum thickness. This system uses related frequencies such as the fundamental and its harmonics to establish a multi-harmonic coherence relationship whereby a homodyne phase reference between harmonics can be conserved and information extracted from just the received and not the transmitted signals. Consequently doppler effects due to motion between the target and the apparatus, as well as severe local oscillator stability and drift limitations are avoided, and thus this system can measure remote target parameters by interferometric techniques without the distance being a constraint.</p> |
申请公布号 |
CA1075311(A) |
申请公布日期 |
1980.04.08 |
申请号 |
CA19770290504 |
申请日期 |
1977.11.09 |
申请人 |
CANADIAN PATENTS AND DEVELOPMENT, LIMITED;MAJESTY (HER) IN RIGHT OF CANADA AS REPRESENTED BY THE DEPARTMENT |
发明人 |
WIGHT, JAMES S.;CHUDOBIAK, WALTER J.;MAKIOS, VASSILIOS |
分类号 |
G01B7/06;G01R25/02;(IPC1-7):01N23/24 |
主分类号 |
G01B7/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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