Design of a Compact Quad‐Band Power Divider Using Short‐Circuited Coupled Lines

ABSTRACT

A compact quad‐band power divider based on short‐circuited coupled lines is proposed. Two‐section parallel coupled lines are employed for impedance transformation, while stepped‐impedance short‐circuited coupled lines are introduced to compensate for the dispersion effects caused by the unequal phase velocities of the even and odd modes, thereby improving impedance matching and multiband performance. Explicit closed‐form synthesis equations and a systematic design procedure are derived through a complete theoretical analysis. To validate the proposed method, a quad‐band power divider operating at 0.9, 1.9, 3.1, and 4.1 GHz is designed, fabricated, and measured. The measured results agree well with the theoretical predictions and simulations, demonstrating satisfactory power division, impedance matching, and isolation performance at all four operating frequencies. Owing to its compact size, low insertion loss, and explicit synthesis capability, the proposed divider is a promising candidate for multistandard RF front‐end applications, including cellular communications, Internet of Things (IoT), broadband wireless systems, and satellite communications.