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A compact spiral‐coupled directional coupler for a mobile RFID reader via integrated passive technology
Author(s) -
Wang Cong,
Jeon Hamhee,
Kim NamYoung
Publication year - 2015
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.29280
Subject(s) - hybrid coupler , spiral (railway) , power dividers and directional couplers , fabrication , microwave , insertion loss , radio frequency identification , rat race coupler , engineering , electrical engineering , electronic engineering , optoelectronics , materials science , computer science , telecommunications , mechanical engineering , medicine , alternative medicine , computer security , pathology
This article presents the design and implementation of a high‐performance, compact spiral‐coupled directional coupler using an advanced integrated passive device (IPD) fabrication process on a GaAs substrate for use in mobile radio frequency identification (RFID) reader applications. The IPD fabrication step is introduced specifically to enable the directional coupler, which is constructed by the transformation of the intertwined mutual inductors and air‐bridges, to have a compact size and high Q‐factor. The fabricated coupler achieves only 0.43 dB of insertion loss S 21 and it exhibits the coupling S 31 of 15.7 dB and the isolation S 41 of 27.2 dB. This presented coupler has an extra small size of only 0.72 × 0.82 mm 2 and an operational frequency of 910 MHz, which is appropriate for use in an RFID reader system. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2142–2146, 2015