Highly stabilized circuit for measuring very low impedance (Rx, Cx) and their small changes (δRx, δCx) at high frequencies with some applications

A new circuit is described for the accurate measurement of the equivalent parallel capacitance C
x
, resistance R
x
of high-loss materials, and also their small changes ΔC
x
, ΔR
x
. The capacitance measurement is not affected by the specimen's resistance when the value of R
x
is greater than 10 Ω. The important characteristic of the new circuit is its ability to measure accurately the value of C
x
, R
x
, and also ΔC
x
, ΔR
x
of very high-loss materials at high frequencies.