Resistance standards with calculable, nearly negligible AC-DC difference at frequencies up to 2 MHz for the calibration of precision LCR meters

Abstract

We have developed novel impedance standards based on thin-film surface-mount-device (SMD) resistors. Due to the small dimensions of such resistors, the quantities determining their frequency dependence are very small and can be either measured or numerically calculated. A series connection of thin-film SMD resistors allows us to further improve the DC and the AC properties. The nominal resistance value of our application is 12.906 kohm but other values are just as possible. At frequencies up to 2 MHz, the calculated frequency dependence amounts to only a few parts per million of the DC value, which is about four orders of magnitude smaller than for all conventional calculable AC-DC resistors having a similar nominal DC value. To measure the frequency dependence, we use a precision inductance-capacitance-resistance (LCR) meter at frequencies up to 2 MHz that has a reproducibility of a few parts per million but a systematic uncertainty which is specified by the manufacturer to increase from 300 parts per million in the lower frequency range to 3000 parts per million at 2 MHz. Measurements of two very different SMD-based resistance standards allow verification of the model calculation as well as the calibration of the precision LCR meter, both with a relative uncertainty of a few parts per million in the whole frequency range. This boost in precision enables new applications in this frequency range such as the verification of conventional calculable resistance standards, the calibration of impedance standards, and future measurements of the quantum Hall resistance.