Systematic Design of Low-Pass Filtering Power Divider

This paper presents four low-pass filtering power dividers (LFPDs) by incorporating even-order Chebyshev low-pass filters (LPFs) into the power divider (PD) structure. Design considerations regarding isolation and high-frequency harmonic suppression are discussed, and the flexibility in achieving both is demonstrated. Unlike previously reported LFPDs, the proposed approach enables systematic design and accurate prediction of low-pass response parameters, such as cutoff frequency, equal-ripple level, and the roll-off rate near the cutoff frequency. Consequently, the proposed LFPDs exhibit a synthesizable and systematic design methodology. Compared with many PDs that integrate bandpass filters (BPFs), also known as bandpass filtering power dividers (BFPDs), the LFPDs offer lower transmission loss, which is highly desirable for high-frequency front-end transmitters.