Reflectometric measurement of plasma imaging and applications

Abstract

Progress in microwave and millimeter-wave technologies has made possible advanced diagnostics for application to various fields, such as, plasma diagnostics, radio astronomy, alien substance detection, airborne and spaceborne imaging radars called as synthetic aperture radars, living body measurements. Transmission, reflection, scattering, and radiation processes of electromagnetic waves are utilized as diagnostic tools. In this report we focus on the reflectometric measurements and applications to biological signals (vital signal detection and breast cancer detection) as well as plasma diagnostics, specifically by use of imaging technique and ultra-wideband radar technique.

Development and application of radar reflectometer using micro to infrared waves

“…It is therefore difficult not only to estimate the stress, but even to measure the heartbeat signal. We have succeeded in reducing the noise component and have extracted only the heartbeat signal by calculating a cross-correlation function between two measurement signals obtained from two microwave reflectometers [83]. The success rate of the heart-rate measurement by reflectometers is 70-80%.…”

Non-contact and real-time measurement of heart rate and heart rate variability using microwave reflectometry

“…In a 10 GHz system, a heterodyne reflectometer using an automatic gain control (AGC) amplifier is utilized to control the reflected wave. 31,32 We have now fabricated a new 24 GHz homodyne reflectometer as shown in Fig. 3.…”

A narrow band-pass filter type Wilkinson power divider for I-Q demodulator in microwave interferometer system

“…Recently, various microwave interferometer systems [1][2][3][4] and reflectometry systems [5][6][7][8][9] are developed for plasma diagnosis applications. The frequency difference between RF (Radio Frequency) signal and LO (Local Oscillation) signal is quite limited, in order to maintain IF (Intermediate Frequency) signal quality, BPF (Band-pass Filter) in I-Q demodulator is essential element, it not only keeps the desired mixing signal, but also suppresses harmonic signals, DC (Direct Current) noises, and reject the image frequencies.…”