Effects of dielectric or magnetic materials to electrical characteristics of very small normal-mode helical antennas

2012 ◽  
Author(s):  
Keita Ochiyama ◽  
Naobumi Michishita ◽  
Yoshihide Yamada
Keyword(s):  
Magnetic Materials ◽  
Normal Mode ◽  
Electrical Characteristics ◽  
Helical Antennas

scholarly journals Investigating Equations Used to Design a Very Small Normal-Mode Helical Antenna in Free Space

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Dang Tien Dung ◽  
Quoc Dinh Nguyen ◽  
Do Quoc Trinh ◽  
Yoshihide Yamada
Keyword(s):  
Normal Mode ◽  
Radio Frequency Identification ◽  
Electrical Characteristics ◽  
Helical Antenna ◽  
Tire Pressure ◽  
Electromagnetic Simulations ◽  
Short Dipole ◽  
Small Loop ◽  
Frequency Identification ◽  
Helical Antennas

A normal-mode helical antenna (NMHA) has been applied in some small devices such as tire pressure monitoring systems (TPMS) and radio frequency identification (RFID) tags. Previously, electrical characteristics of NMHA were obtained through electromagnetic simulations. In practical design of NMHA, equational expressions for the main electrical characteristics are more convenient. Electrical performances of NMHA can be expressed by a combination of a short dipole and small loops. Applicability of equations for a short dipole and a small loop to very small normal-mode helical antennas such as antennas around 1/100 wavelengths was not clear. In this paper, accuracies of equations for input resistances, antenna efficiency, and axial ratios are verified by comparisons with electromagnetic simulation results by FEKO software at 402 MHz. In addition, the structure of the antenna equal to 0.021 λ is fabricated, and measurements are performed to confirm the design accuracy.

High performance normal mode helical antennas for RFID tags

2007 ◽  
Author(s):  
Won gook Hong ◽  
Woong hyun Jung ◽  
Yoshihide Yamada ◽  
Naobumi Michishita
Keyword(s):  
Normal Mode ◽  
High Performance ◽  
Rfid Tags ◽  
Helical Antennas

Deterministic Equation of Self-Resonant Structures for Normal-Mode Helical Antennas Implanted in a Human Body

2018 ◽  
Vol 17 (8) ◽  
pp. 1377-1381 ◽  
Author(s):  
Nguyen T. Tuan ◽  
Yoshihide Yamada ◽  
Nguyen Q. Dinh ◽  
Rasyidah H. B. M. Baharin ◽  
Kamilia B. Kamardin ◽  
...  
Keyword(s):  
Normal Mode ◽  
Human Body ◽  
Deterministic Equation ◽  
Resonant Structures ◽  
Helical Antennas
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