A novel and fast prototype‐based approach is presented to design LTCC band pass filters (BPFs) using two reflection zeros for 2.4 GHz WLAN / 2.3 GHz worldwide interoperability for microwave access dual‐mode applications. The proposed approach derives quite compact formulas for synthesizing a filter prototype to meet the specification requirements in the passband insertion loss and stopband attenuation. From real‐time prototype simulation prediction, one can efficiently minimize the filter size under various electrical specifications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:8–11, 2014