A design of unequal power divider with positive and negative group delays

This paper presents group delay investigation and implementation of unequal power divider with very high power division ratio. The proposed structure consists of Wilkinson power divider and branch-line where direct and coupled ports are terminated with resistors. By analytically study, the group delay associated with transmission paths between 3 and 1 is negative whereas the group delay associated between transmission path 2 and 1 is positive. Moreover, the negative group delay (NGD) characteristics are purely controlled by resistor connected in branch-line. For experimental validation, the power divider with power division ratio of 21.39 dB and NGD of -0.529 ns was designed, fabricated and measured at center frequency of 2.14 GHz.