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A novel tri‐band rat race coupler with T‐shape step impedance transformers
Author(s) -
Chu QingXin,
Lin Feng
Publication year - 2010
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.25186
Subject(s) - rat race coupler , transformer , microwave , electrical impedance , microstrip , wavelength , frequency band , engineering , electrical engineering , hybrid coupler , acoustics , materials science , electronic engineering , physics , optoelectronics , telecommunications , power dividers and directional couplers , voltage , antenna (radio)
A novel tri‐band 3‐dB rat race coupler operating at two arbitrary frequencies and their mean frequency is presented through replacing quarter‐wavelength impedance transformers in a conventional rat race coupler by T‐shape step impedance transformers, which can be equivalent to quarter‐wavelength impedance transformers at the three frequencies. Closed‐form design equations are derived. For verification, a microstrip tri‐band 3‐dB rat race coupler operating at 1.5/3.5/5.5 GHz is fabricated, aimed to cover the 1.5 GHz GPS band, and the 3.5/5.5 GHz WiMAX bands. Simulated and measured results are in good agreement. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1240–1244, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25186