presentation tuan antenna
DESCRIPTION
Presentation Tuan AntennaTRANSCRIPT
Research subject: Determination of Structural Equation for Normal Mode Helical Antenna having
Dielectric or Magnetic Material inside
Presented by : Nguyen Thanh Tuan (First Semester of Master Degree)
Supervisor : Prof. Dr. Yoshihide Yamada
Co-Supervisor : Dr. A.K.M Muzahidul Islam Assoc. Prof. Dr. Sabariah Bt. Baharun
27th March 2015
Outline of this presentation
1. What is Antenna ?
2. What is Normal Mode Helical Antenna (NMHA) ?
3. Structural Determination Method
4. Study Subject
5. Research Schedule
6. Present Situation
7. Conclusion
1. What is Antenna ?
Fig 1.Mobile Communication Fig 2.Satellite Communication
• Applications of Antennas:
• Main roles: Transmit and receive radio wave• Important characteristics: Antenna gain, Radiation pattern,
Impedance matching to radio equipments.
AntennaAntenna
1. What is Antenna ?
Long distance Communication
Short distance Communication
Parabolic Reflectors
Array Antennas
Patch Antennas
Helical Antennas
• Categorization of Antennas:
High Gain Low gain, Small Size
Tag Antenna
Antennas for Radio Frequency Identification (RFID)
Antennas for Tire Pressure Monitoring System (TPMS)
• Application of Small Antenna:
Normal-Mode Helical Antenna (NMHA)
1. What is Antenna ?
Reader Antenna
2. What is NMHA ?
Categorization of Helical Antennas
Axial Mode
Normal Mode Radiation Pattern
• Main radiation is in the antenna axis direction
• Circumference (C) is one wavelength (λ)
• Applications: Satellite ant, Circular polarization ant.
• Main radiation is in the normal direction of the antenna axis
• Height of antenna is less than 1/100 wavelength (λ)
• Applications: RFID tag, TPMS
H
~HA
DA
~
RD - jXDRL + jXL
N
2. What is NMHA ?
• Operational Explaination of NMHA
N
Small Dipole
Small LoopsH << λ
• Electrical Working Condition:Resonant Structure: XC = XL
XC: CapacitanceXL: Inductance
Treatment: Antenna current is divided into 2 parts: the straight part (small dipole) and circular parts (small loops)
3. Structural Determination Method
0.005 0.010 0.015 0.020 0.025 0.0300.005
0.010
0.015
0.020
0.025
0.030
0 2 4 6 8 10
DA/
HA/
N = 5
N = 7
N = 11
f0 = 315 MHzλ = 0.95 md = 0.55 mm
Self-Resonant Structure
• Equation for self-resonant structures (in Free Space ε0 =1)
AA
A
AA
A
HD
DN
DHN
H
209
)(7.19600
)92.0(
279 2
2
XC=XL
• Equation for Input impedance)( CLlrLrDin XXjRRRZ
In self resonant-structure, XL = XC so Zin = Rin = RrD + RrL + Rl
Here, RrD, RrL are the radiation resistance of the small dipole, small loops and Rl is the ohmic resistance of the antenna wire, respectively.
4. Study Subject
Actual NMHA
• Study about resonance structures in dielectric or magnetic (by Electromagnetic simulations)
• Electric field and Magnetic field distributions in dielectric or magnetic
• From resonance curves, we derive resonance equation.
• Determination of Structural Equation for Normal Mode Helical Antenna having Dielectric or Magnetic Material inside (ε1, µ1)
5. Research Schedule
Study of NMHA
Fablication and
measurement of NMHA
Learning of FEKO (EM
Simulation)
Calculate resonant
structures at ε=εi µ=µi
(not Free Space)
Summarizesimulated results
Find out structural equation
March, April, May 2015
June, July, Aug, Sept
2015
Oct, Nov, Dec2015
Jan, Feb2016
March, April, May 2016
• Research Steps:
6. Present Situation
Caculation of Self-resonant Structure
Rin
Rl
Caculation of Input Resistance
Calculation of self-resonant structures and input resistance (in Free Space ε0)
7. Conclusion
• Now, fundamentals of NMHA are studying
• Next subject is to learn an electromagnetic simulator
• Obtain resonant structural data of NMHA in dielectric and
magnetic materials.
Thank you for your attention