Title :
A novel open-resonator system for precise measurement of permittivity and loss-tangent
Author :
Afsar, Mohammed Nurul ; Ding, Hanyi
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Tufts Univ., Medford, MA, USA
fDate :
4/1/2001 12:00:00 AM
Abstract :
A simplified open resonator system is developed for the first time for the measurement of permittivity and loss tangent of low-loss materials with high accuracy. In this new system, a cavity length variation technique and a quasioptical detection technique are developed and implemented. The cavity length variation technique makes it possible to use only fixed frequency sources. The use of the quasioptical detection technique employing a lens refocusing system and an ultra sensitive liquid helium cooled detector allows us to utilize only one fixed frequency source in the system. This novel open-resonator system has a much simpler structure, it is inexpensive and provides same level of measurement accuracy compared to the system using a super-heterodyne receiver (two fixed frequency sources). Permittivity and loss tangent data of a number of fused silica specimens are measured using this simplified open resonator system and are compared to data obtained by the open-resonator system using a super-heterodyne receiver
Keywords :
Q-factor; cavity resonators; dielectric loss measurement; microwave measurement; permittivity measurement; superheterodyne receivers; InSb detector; SiO2; cavity length variation; fixed frequency source; fixed frequency sources; fused silica specimens; lens refocusing; liquid helium cooled detector; loss-tangent measurement; low-loss materials; open resonator; permittivity measurement; precise measurement; quasioptical detection; super-heterodyne receiver; Detectors; Frequency measurement; Helium; Lenses; Loss measurement; Millimeter wave measurements; Mirrors; Permittivity measurement; Q factor; Time measurement;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on