Instrumentation of a high-sensitivity microwave vector detection system for low-temperature applications
Journal
Review of Scientific Instruments
Journal Volume
76
Journal Issue
8
Pages
1-7
Date Issued
2005
Author(s)
CHIEH-HSIUNG KUAN
Suen, Y.W.
Hsieh, W.H.
Chen, C.L.
Li, L.C.
CHIEH-HSIUNG KUAN
Abstract
We present the design and the circuit details of a high-sensitivity microwave vector detection system, which is aiming to study the low-dimensional electron system embedded in the slots of a coplanar waveguide at low temperatures. The coplanar waveguide sample is placed inside a phase-locked loop; the phase change of the sample may cause a corresponding change in the operation frequency, which can be measured precisely. We also employ a double-pulse modulation on the microwave signals, which comprises a fast pulse modulation for gated averaging and a slow pulse modulation for lock-in detection. In measurements on real samples at low temperatures, this system provides much better resolutions in both amplitude and phase than most of the conventional vector analyzers at power levels below −65dBm in the frequency range from 100 MHz to 18 GHz.
SDGs
Type
journal article