A wide-band tunable phase shifter for radio-frequency reflectometry

TL;DR

This paper presents a tunable phase shifter based on a varactor-loaded transmission line, enabling effective separation of signal quadratures in radio-frequency reflectometry of nanodevices across 100 MHz to 1 GHz.

Contribution

It introduces a wide-band, tunable phase shifter with acceptable insertion loss suitable for radio-frequency reflectometry applications.

Findings

Successfully demodulates resistance and capacitance signals separately.

Operates effectively across 100 MHz to 1 GHz frequency range.

Demonstrates practical use in nanodevice impedance measurements.

Abstract

Radio-frequency reflectometry of nanodevices requires careful separation of signal quadratures to distinguish dissipative and dispersive contributions to the device impedance. A tunable phase shifter for this purpose is described and characterized. The phase shifter, consisting of a varactor-loaded transmission line, has the necessary tuning range combined with acceptable insertion loss across a frequency band 100 MHz - 1 GHz spanning most radio-frequency experiments. Its operation is demonstrated by demodulating separately the signals due to resistance and capacitance changes in a model device.