ISBN 9783843925686

978-3-8439-2568-6, Reihe Physik

Jan-Martin Rämer
A Terahertz Time-Domain Spectroscopy-based Vector Network Analyzer Setup with Integrated Pulse Shaping

129 Seiten, Dissertation Technische Universität Kaiserslautern (2016), Softcover, A5

Zusammenfassung / Abstract

Since the first demonstration of a transistor, electronic circuits have become ever more complex. Their operating frequency has also increased by orders of magnitude and is now reaching into the THz range. Though this spectral region, typically characterized as the range from 100 GHz to 5 THz, offers many applications in the fields of communications, radar, imaging and spectroscopy, measurement equipment needed for the development of such devices is at best expensive and at worst not commercially available. The vector network analyzer (VNA), allowing for the measurement of S-parameters describing the transmission and reflection of an electronic device in amplitude and phase, is probably the most important tool for characterization of newly developed devices. But even the most advanced commercially available extension modules do not allow for measurements above 1.1 THz, while amplifiers operating at 850 GHz as well as transistors with a measured response up to 1.1 THz have been demonstrated. In case of the transistors, an operation up to 1.5 THz has been extrapolated, but cannot be measured due to the lack of suitable measurement equipment.

Such equipment must retain several aspects of conventional VNAs for real-life applications: it should be packaged in a compact way with measurement heads fitting existing wafer-probers, while allowing for vector measurements of amplitude and phase. To be compatible with existing devices under test (DUTs) as well as conventional probes, a rectangular waveguide interface is required. Finally, a broad bandwidth is needed, allowing for measurements at frequencies not reached by conventional VNAs.

As one potential solution for this problem, this work describes the application of THz time-domain spectroscopy (THz-TDS) to replace the conventional VNA. Furthermore, the setup built in this work allows for the generation of user-defined THz waveforms, in contrast to conventional VNAs, generating only sine signals. Moreover, first steps towards usage in industry are taken by integrating the setup in a compact housing and developing compact, fiber-coupled measurement modules with rectangular waveguide interfaces, allowing for mounting on wafer prober as well as directly connecting to waveguide-coupled DUTs.