Leiden University Student Repository

Lensen, Sietske (2017)

Design of an STM circuit suitable for GHz signal measurements

Bachelor thesis | Natuurkunde (BSc)

The goal of this thesis is to investigate the possibilities of building a GHz compatible circuit that will allow high frequency measurements with a Scanning Tunneling Microscope. In this frequency range, many interesting properties of materials could be accessed, as for example shot noise in the tunneling current. The main problem in these kinds of measurements is the mismatch between the very high impedance of the tunneling junction and the 50 Ω impedance of the measurement circuitry, which causes the high frequency signal to be reflected back. Here, two solutions to this problem - lumped and distributed impedance matching - are theoretically described and simulated in order to determine their advantages and disadvantages. Lastly, a distributed resonating circuit is built and measured, with the purpose of investigating potential difficulties in distributed circuits on a PCB.

STM

GHz

Design

Author

Lensen, Sietske

Faculty

Faculty of Science

Specialisation

BA Physics

Supervisors

Allan, Milan

ECTS Credits

3

Language

en