This document proposes detecting the position of a device using the swept frequency of microwaves on a two-dimensional communication system. It collects data on the current sensed by a receiving antenna as an oscillator shifts microwave frequencies and an XY-plotter moves the antenna. This data is applied to a support vector machine to generate an electric field distribution map and detect the antenna's position with 79.1% accuracy when the detection points have an interval of 12mm.

1. 06
03
Detecting Position of a Device by Swept Frequency of Microwave
on Two-Dimensional Communication System
01 Introduction
02
Two-dimensional
Communication
Detecting position is important technique and
utilized in wide ranges of fields.
• Ubiquitous computing
• Tangible user interfaces
• Robotics
Background
Existing detecting position system, such as using
camera or SLAM, has some problems.
• Occlusion
• Cost and size of sensors
• Difficulty of implementation
Problem
• Utilizing a two-dimensional communication
(2DC) system. It provides electric power to a
device via a 2DC sheet.
• We detect the antenna’s position by sensing
the supplied electric power.
Approach
04 Data Collection
• Oscillator shifts frequency of microwave
(2.20GHz, 2.21GHz, 2.22GHz, …, 2.50GHz)
• XY-plotter moves receiving antenna
• Microcontroller senses a current in antenna and send
the sensor values to a PC
• Applying the collected data (31 dimension sensor
values) to Support Vector Machine (SVM)
05 Electric Distribution Map
Contact flatjun@imlab.ics.keio.ac.jp
Junya Taira Suzanne Low Maki Sugimoto Yuta Sugiura
Automatic Electrical Field Mapping System Power Receiving Antenna
State of electric field map acquired when manipulating frequency of
electromagnetic waves output from transmitter in increments of 0.01GHz
Relationship Between Resolution and
Recognition Accuracy of Position Detection
• 22 times of frequency sweeping
on each point from 2.20Ghz to
2.50GHz in steps of 0.01GHz
• 22 fold cross validation to
estimate the accuracy
• The detection of each point
with an interval of 12 mm
where we observed that the
accuracy is 79.1 % (256
classification).
SVM Learning Data
Position
Detection
Learning Phase
Position Detecting Phase
Standing Wave
Evanescent Wave (Electric Power)
2DC Sheet
Principle
Evaluations
Akihito Noda and Hiroyuki Shinoda: Selective Wireless Power
Transmission through High-Q Flat Waveguide-Ring Resonator on 2D
Waveguide Sheet, IEEE Transactions on Microwave Theory and
Techniques, Vol. 59, No. 8, pp.2158-2167, August 2011.
Keio University