Spiral Monopole Antenna Research Articles

Compact tag antenna for UHF active RFID applications

By introducing an L-shaped metal plate connecting with the spiral monopole antenna, a planar compact ultra-high-frequency (UHF) tag antenna for radiofrequency identification system is proposed. With the overall antenna size of only 13 × 9 × 1.6 mm3, the proposed tag antenna provides the measured impedance bandwidth of 12 MHz to comply with Taiwan UHF operating band (922–928 MHz). The measured peak gain and antenna efficiency are approximately −1.1 dBi and 27% for Taiwan UHF band, respectively. Meanwhile, the measured reading distance can approach 250 m. Good tag sensitivity is obtained across the desired frequency band.

Body-Worn Spiral Monopole Antenna for On-Body Communications

A novel body-worn spiral monopole antenna is presented. The antenna consists of a ground plane and a spiral monopole. The antenna was designed for Ear-to-Ear (E2E) communication between In-the-Ear (ITE) hearing instruments at 2.45 GHz and has been simulated, prototyped, and measured. The antenna yielded a measured and simulated E2E path gain at 2.45 GHz of ?82.1 dB and ?85.9 dB, respectively. The radiation pattern of the antenna when mounted in the ear is presented and discussed.

이중 대역 동작을 위한 변형 스파이럴 모노폴 인쇄형 안테나 설계

In this paper, modified spiral monopole printed antenna for dual band operation in GPS(1.57~1.577 GHz) and WiBro(2.3~2.4 GHz), WLAN(2.4~2.48 GHz) is proposed. To control the frequency ratio of the antenna for dual band operation freely, distance between inner lines of the spiral is diversified by using the different current distribution between basic resonance frequency of spiral monopole antenna and harmonic resonance frequency. And also the branch line is inserted. Bandwidth(-10 dB) of the antenna is measured 140 MHz(1.47~1.61 GHz) in basic resonance frequency and 420 MHz(2.29~2.71 GHz) in harmonic resonance frequency. The peak antenna gains are measured 2.825 dBi in GPS(1.57 GHz), and 3.65 dBi in WiBro(2.35 GHz), and 4.564 dBi in WLAN(2.44 GHz).