Sunday, January 11, 2015
Abstract-A Terahertz Time Domain Spectroscopy-based Network Analyzer
Ramer, Jan-Martin ; Jan-Martin Ramer is with the department of material characterization of Fraunhofer institute for physical measurement techniques IPM, Fraunhofer- Platz 1, 67663 Kaiserslautern and the department of physics of the University of Kaiserslautern as well as the state research center OPTIMAS, Erwin-Schrodinger-Straße 56, 67663 Kaiserslautern (e-mail: Jan- Martin.Raemer@ipm.fraunhofer.de). ; von Freymann, G.
We present a terahertz time domain spectroscopybased setup based on photoconductive antennas and a femtosecond fiber laser for measuring the transmission S parameters of electronic devices. To this end, radiation is focused into horn antennas attached to the waveguide-coupled devices under test and coupled out of the device using a similar setup. The terahertz emitter is fiber-coupled in order to allow for flexible selection the measurement geometry. As test cases, the S21 parameters of several H band (220-330 GHz) amplifiers are measured and show promising results. Also, the response of a W band amplifier is measured, marking the lower frequency boundary for this setup. In both cases, the measurements are compared to measurements retrieved using a commercially available vector network analyzer with frequency extenders, showing rather good agreement. Transmission measurements of “thru” waveguides used as a reference imply our system’s ability to measure up to at least 2.5 THz, widely exceeding the bandwidth of currently available network analyzers.