The high balance symmetric balun for WLAN and WiMAX application using the Integrated Passive Device (IPD) technology

In this study, the design of planar symmetric balance circuit and perform the high-balance differential output frequency response for system-in-package (SiP) application using the integrated passive device (IPD) technology are proposed. Passive balun with single-end input and differential output is an important device in RF front-end communication system. The merits of passive component are no power dispersion and have wide frequency bands. The design of this planar symmetric balun is broadband and covers the frequency band of 2 to 4.2 GHz. It can apply to the 2.4 GHz WLAN and 3.4 to 3.7 GHz WiMAX applications. The measured return loss is better than -10 dB within the pass band. The measurement results of magnitude and phase imbalance are lower 0.8 dB and 0.03 degrees, respectively.