Millimeter-Wave Thermoelectric Power Transfer Standard

Abstract

This paper describes a thermoelectric waveguide power sensor for the frequency range 75-110 GHz, which has been calibrated in a waveguide twin-type microcalorimeter. The sensor is suitable as a transfer standard to provide traceablity for high-frequency power calibrations. The design and calibration of the sensor are described. The calibration is based upon a novel measuring quantity, referred to as generalized efficiency. The results of mirocalorimeter measurements and sensor performance are given. The new transfer sensor is tested against conventional thermistor waveguide sensors in a direct comparison setup, showing good agreement within the estimated uncertainties. Index Terms-Millimeter-wave power transfer standard, thermoelectric power sensor, traceability, twin-type microcalorimeter, waveguide power sensor. Rolf H. Judaschke (M'93-SM'08) received the Dipl.-Ing. degree in electrical engineering from the Technische Universität Braunschweig, Braunschweig, Germany, in 1991, and the Dr.-Ing. degree from the Technische Universität Hamburg-Harburg, Hamburg, Germany, in 1997. He was with the Technische Universität Hamburg-Harburg from 1991 to 2004, where he was involved in the development of millimeter-wave solid-state oscillators, multipliers, antennas, radar, and power combiners. In 2005, he joined the Physikalisch-Technische Bundesanstalt, Braunschweig, where he is involved in the measurement of high frequency quantities. Dr. Judaschke is a member of the Union Radio Scientifique Internationale.This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. JUDASCHKE et al.: MILLIMETER-WAVE THERMOELECTRIC POWER TRANSFER STANDARD 7 Karsten Kuhlmann received the Dipl.-Ing. degree from the Technische Universität Braunschweig, Braunschweig, Germany, in 2004, and the Dr.-Ing. degree from the Technische Universität Hamburg-Harburg, Hamburg, Germany, in 2010. He has been with the Physikalisch-Technische Bundesanstalt, Braunschweig, since 2009. His current research interests include smart antennas and metrology at millimeter-wave frequencies and beyond. Thomas M. Reichel received the Dipl.-Ing. degree in electrical engineering from the Technische

RF/MW Power Standard Realization Without Unitary Efficiency Assumption at DC/LF

“…Our results need to be confirmed by measuring several other sensors, because other measurements in literature [14] seems to highlight a not perfect thermal coupling between the RF absorber and the auxiliary heater of a similar waveguide sensor. By measuring a device in 7mm coaxial line up to 18 GHz, we did not find such thermal imbalance.…”

“…This has been suggested due to the lack of commercial bolometric sensors, but is also motivated by the superior performance of thermoelectric sensors, as it has been demonstrated for the coaxial case at least, [4], [12], [13]. Recently a noticeable W-band waveguide power standard has been realized by using a thermoelectric sensor that is fed via a waveguide to coplanar waveguide transition line [14].…”

“…However, from our point of view, the most interesting characteristic of the device used in [14] consists of an additional auxiliary heater, placed near the RF/MW load, but electrically insulated from it. Sensors exploiting this feature have been recently introduced with coaxial input line also [15].…”

WG29/WR7 Band Thermoelectric Power Sensor Characterization using Microcalorimetry Technique

“…coaxial or waveguide. Waveguide microcalorimeters have been preferred for higher frequencies because of availability of transfer standards, relatively small uncertainties, and relatively easy realization [4]. In recent years, microwave applications at high frequencies have increased with 5G wireless technology, autonomous vehicles, internet of things, high-speed digital communications, etc.…”

“…The transfer standard is a thermoelectric sensor which contains a thermopile, a microwave termination, and a DC heater [4]. The thermopile is used to detect temperature differences caused by the dissipated microwave and DC power on the microwave termination and/or DC heater.…”