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Quarter‐wavelength printed quadrifilar helical antenna design for UHF RFID handheld reader applications
Author(s) -
Chiu ChienWen,
Wang WeiHsu,
Wang HwangCheng
Publication year - 2018
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.31035
Subject(s) - ultra high frequency , beamwidth , electrical engineering , ranging , bandwidth (computing) , axial ratio , resonator , antenna (radio) , physics , engineering , optics , telecommunications , microstrip antenna
This article presents a compact size and light weight PQHA for handheld UHF RFID reader applications. Quarter‐wavelength inverted‐F resonators are employed as the basic radiation elements for the four arms of the QHA. The height of the designed reader antenna is only 27 mm so that it features compact size but still preserves satisfactory electrical performance. The antenna is fed by a four‐port quadrature phase feeding system fabricated by only lumped elements. The feeding system printed on a FR4 substrate measures only 60 × 60 × 1.6 mm 3 . The measured fractional bandwidth of the proposed PQHA system is about 21% and the 3‐dB axial ratio bandwidth ranging from 800 to 1000 MHz covers the whole UHF RFID band. The measured maximum gain is around 3.2 dBic in the North American band and the 3‐dB beamwidth is about 120° at 920 MHz. The measured reading distance along line of sight is approximately 7.2 m using a commercial 4W EIRP reader and a standard tag. The advantages of the antenna are easy implementation, light weight and low cost, making it suitable for handheld UHF RFID reader applications.