Microwave broadband free-space complex dielectric permittivity measurements on low loss solids

A single layer free-space measurement system operating in the 1.5-23 GHz pequency range is used to measure the transmission coeflcient, Szi, of low loss soli&. The mearurement system consists of hvo double-ridged horn antennas, a pair of collimating lenses, a pair of plano-convex focusing lenses, a mounting station mode ofaluminum, and an Agilent 851OC Vector Newark Analyzer. 201 measured values of S2i are transferredfrom the nehvork analyzer to the PC using a general purpose interface bus (GPIB) utilizing the IEEE-488 protocols. The development sofmore, LabView, is used to compute and analyze the complex dielectric permittivity of the low loss solids A pee-space TRL calibration technique is used to correct the errors due to multiple reflections. Results are reported in the 15-20 GHzpequency range for low loss solids such as polyethylene, polypropylene, teflon, polycarbonate, acrylic. fiberglass. nylon, white delrin, ceramic glass, and borosilicate glass.

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