A 1∶8 cascaded Wilkinson power divider

A high ratio Wilkinson power divider is produced by cascading low ratio dividers. Combining two 1:2 and one 1:3 divider results in a 1:8 ratio. Theoretically the 1:8 divider has an S21 of -0.51dB and an S31 of -9.54dB. Under simulation the average S21 over a 1.7-2.7GHz band was -0.7dB and the S31 -10.3dB. A prototype was built on standard 1.6mm FR4 substrate. The 1:3 divider uses stacked substrates. Doubling substrate thickness allows a high impedance line to be realized at a sensible width. The measured average S21 was -1.6dB and the S31 -11.2dB. The FR4 substrate has an estimated loss of 1.4dB. Allowing for this loss, the power divider is operating close to the theory.