A fast negative impedance converter for JAWS load compensation

For accurate realization of the ac volt, the Josephson Arbitrary Waveform Synthesizer must not be overly loaded by the electrical network in which it is used. The interaction between its output inductance and stray capacitance in the network can yield significant errors. Such errors are compounded for low-impedance devices, such as thermal transfer standards (TTS). This paper describes a negative impedance converter that has been designed to handle such loads up to 100 kHz. We discuss the motivation for the device, its design, and present some initial ac-ac difference measurements with a TTS.