UNEQUAL TERMINATION BRANCH-LINE BALUN WITH HIGH-ISOLATION WIDEBAND CHARACTERISTICS

作者：Kim Phirun; Chaudhary Girdhari; Jeong Yongchae^*

来源：Microwave and Optical Technology Letters, 2016, 58(8): 1775-1778.

DOI：10.1002/mop.29914

• branch-line balun
• coupled line
• isolation circuit
• unequal termination impedance
• wideband

This article presents a design of an unequal termination impedance branch-line balun with wideband high isolation. The wideband and high isolation characteristics are obtained only in the under-matched region. For an experimental verification, the proposed balun was designed at a center frequency (f(0)) of 2.6 GHz. The measured results are in good agreement with the simulations. From the measurement, the power divisions are -3.29 dB and -3.3 dB. The return loss at f(0) is 22.3 dB and is higher than 20 dB over a bandwidth of 0.51 GHz. The isolation between output ports is higher than 19 dB for the bandwidth of 0.64 GHz. The phase imbalance between two output ports is 180 degrees +/- 5 degrees for the bandwidth of 0.64 GHz.

• 出版日期2016-8