body scanner reflectometer
TRANSCRIPT
-
7/27/2019 Body Scanner Reflectometer
1/19
Prepared by : MD. NAVID BIN ANWAR
M. Number: 314848
Supervisor: Xuan Anh Nghiem
Prof. Dr. sc. techn. Renato NegraAssistant Professor, Mixed-Signal CMOS circuits
BODY SCANNERREFLECTOMETER
-
7/27/2019 Body Scanner Reflectometer
2/19
Introduction
Reflectometer
*The reflectometer is a measurement device that is
mainly used in high-frequency electronics. It allows
one to measure the amplitude ratio or the phase
difference of two electromagnetic waves or both ofthem. The most frequent use of this device is for
measuring the so-called complex reflection
coefficient of a device under test (DUT), which is the
ratio of the wave reflected by the DUT to the wave
incident to the DUT.
-
7/27/2019 Body Scanner Reflectometer
3/19
Six-Port Reflectometer Over
Four-Port Network Analyzers*Simple structure
*Requirement for fewer components
*Measure only the amplitude (or power) of
signals
-
7/27/2019 Body Scanner Reflectometer
4/19
REFLECTOMETER DESIGN
*Waveguide 6-ports
*1826.5 GHz (WR-42)3
*26.540 GHz (WR-28)
*4050 GHz (WR-22)
*5075 GHz (WR-15)
*75110 GHz (WR-10)
-
7/27/2019 Body Scanner Reflectometer
5/19
REFLECTOMETER DESIGN* A. WR-15 Reflectometer: (V-band (5075 GHz))
The six-port module, shown in Fig. 1, consists of asection of WR-15 waveguide and three probe channels thataccommodate microstrip waveguide probes with integratedzero-bias Schottky diode detectors. Note that because onlythree detectors are utilized, the reflectometer is actually afive ports (which can be considered a simplified version of thesixport). Provided the device to be measured is known apriori
to be passive, only three detectors are required to uniquelydetermine its reflection coefficient. The fourth detector maybe used to enhance measurement accuracy, but strictly is notrequired. Bias protection circuits are included in the detectoroutput to reduce the likelihood of damage to the zero-biasSchottky diodes through electrostatic discharge.
-
7/27/2019 Body Scanner Reflectometer
6/19
-
7/27/2019 Body Scanner Reflectometer
7/19
-
7/27/2019 Body Scanner Reflectometer
8/19
Body Scanning by
Reflectometer*Image Focusing
By means of a lens or by an extended
aperture. The beamwidth of an aperture
antenna is related to its size and thefrequency which usually leads to huge
apertures.A drawback is the field ofviewwhich is only big enough to fit onto a person
several meters away from the sensor and
only in the farfield a sharp beam isgenerated.
-
7/27/2019 Body Scanner Reflectometer
9/19
-
7/27/2019 Body Scanner Reflectometer
10/19
-
7/27/2019 Body Scanner Reflectometer
11/19
-
7/27/2019 Body Scanner Reflectometer
12/19
-
7/27/2019 Body Scanner Reflectometer
13/19
Body Scanning by
Reflectometer*The MMW systems are based on a real-time mechanical
scanning architecture. They can image hidden objects and are
an alternative for security applications.
-
7/27/2019 Body Scanner Reflectometer
14/19
Imaging System
*The MMW image recovers the objects beneath theclothes very well. The image also shows a major
disadvantage of perpendicular illumination. Parts of
the body, which are directed perpendicular with
respect to the incident field lead to spots of high
reflectivity which overlay the received signal fromthe objects and clutter the image. The specular
reflections are highly dependent on the TXDUTRX
geometry and change rapidly as this geometry
varies. To overcome that problem it is advisable to
sense the DUT from many viewing angles.
-
7/27/2019 Body Scanner Reflectometer
15/19
-
7/27/2019 Body Scanner Reflectometer
16/19
-
7/27/2019 Body Scanner Reflectometer
17/19
-
7/27/2019 Body Scanner Reflectometer
18/19
-
7/27/2019 Body Scanner Reflectometer
19/19