A novel design approach to the miniaturization of dual-band branch-line coupler

作者：Mirzaee Milad^*; Nosrati Mehdi

来源：IEICE Electronics Express, 2011, 8(24): 2029-2034.

DOI：10.1587/elex.8.2029

• folded-T-type stepped-impedance-stub
• dual-band branch-line coupler
• extremely compact size

In this paper, a novel design approach for significant size reduction of a class of dual-band branch-line coupler (BLC) by use of a transmission line model loaded with a folded-T-type stepped-impedance- stub (FTTSIS) is proposed. At the first step, by loading FTTSIS at the middle of each branch instead of stepped-impedance-stub (SIS) in the conventional branch-line coupler, a compact dual-band BLC with same performance that is about 65% of the conventional one is achieved. Then by mirroring the FTTSISs of 35 Omega lines inside the inner space of the proposed structure, miniaturized dual-band BLC that is only 30% of the conventional dual-band BLC operating at same WLAN frequencies is obtained. The proposed structure is then fabricated and measured. The measurement results show good agreement with the theoretical ones.

• 出版日期2011-12-25