Design of filtering power divider with high frequency selectivity

Abstract

AbstractA novel controllable wideband filtering power divider (FPD) with sharp roll‐off skirt and good isolation is presented in this article. By introducing a pair of coupled lines and several uniformed quarter‐wavelength microstrip lines to the power divider, a wide flat passband with good selectivity is achieved. A resistor is then arranged between the 2 coupled line structures to obtain good isolation. Even‐mode and odd‐mode approach is applied to deduce the design equations of the proposed FPD. The center frequency can be adjusted flexibly by simply controlling the length of the coupled lines and the other microstrip lines. Eventually, the proposed power divider centered at 2.3 GHz with a fractional bandwidth of 75% is fabricated and measured for verification. The measured minimum in‐band insertion loss is 0.3 dB, while the isolation is better than 20 dB. Good agreement is shown between the simulated and measured results.