DocumentCode :
191156
Title :
A microwave permittivity sensing system based on a hybrid heterodyne reflectometer circuit
Author :
Nehring, J. ; Schuetz, M. ; Weigel, R. ; Kissinger, D.
Author_Institution :
Inst. for Electron. Eng., Univ. of Erlangen-Nuremberg, Erlangen, Germany
fYear :
2014
fDate :
6-9 Oct. 2014
Firstpage :
159
Lastpage :
162
Abstract :
In this paper a microwave permittivity sensing system based on a super-heterodyne reflectometer is presented. A set of two high directivity directional couplers is utilized for the derivation of a reference and a reflection measurement channel from a 14 -18 GHz stimulus. Integrated Gilbert-cell circuits were fabricated in a SiGe HBT technology and act as frequency converters for the high frequency measurement signals to an intermediate frequency of 1 GHz. A second mixer stage is implemented for further down-conversion to a second IF as low as 20 kHz. Low-cost analog-to-digital converters and a digital signal processor provide the measurement results on a serial interface. Permittivity measurements with a coaxial dielectric probe were performed on five different mixture ratios of ethanol and methanol.
Keywords :
Ge-Si alloys; analogue-digital conversion; digital signal processing chips; directional couplers; frequency convertors; heterojunction bipolar transistors; mixers (circuits); permittivity measurement; reflectometers; SiGe; SiGe HBT technology; coaxial dielectric probe; digital signal processor; down-conversion; frequency 1 GHz; frequency 14 GHz to 18 GHz; frequency converters; high directivity directional couplers; high frequency measurement signals; integrated Gilbert-cell circuits; low-cost analog-to-digital converters; microwave permittivity sensing system; permittivity measurements; reflection measurement channel; second mixer stage; serial interface; super-heterodyne reflectometer; Microwave circuits; Microwave measurement; Mixers; Permittivity measurement; Sensors; Dielectric measurement; Microwave sensors; Reflectometry;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Microwave Conference (EuMC), 2014 44th European
Conference_Location :
Rome
Type :
conf
DOI :
10.1109/EuMC.2014.6986394
Filename :
6986394
Link To Document :
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