Frequency-independent voltage amplitude across a tunnel junction

Radio-frequency (rf) scanning tunneling microscopy has recently been advanced to methods such as single-atom spin resonance. Such benefit from a frequency-independent rf voltage amplitude across the tunnel junction, which is challenging achieve due strong frequency dependence of attenuation in transmission line. Two calibration for have reported date. In this Note, we present an alternative method junction and show results calibration. The presented procedure applicable devices that can deliver junction.