Compact Ultra-Wideband 8-way Power Divider with Printed Resistors

This paper presents a compact ultra-wideband 8-way power divider with printed resistors. 8-way power division is achieved in three stages with each stage employing a 2-way equal power divider. To achieve ultra-wideband response, a resistive power divider using carbon ink is used at stage 1 due to its frequency independent nature. In stage 2 and 3, tee-junctions are utilized for an equal power division. Microstrip lines are tapered to transform the 25 O impedance of the tee-junction to 50 O of the input port. Tapered microstrip lines are meandered to make the design compact. A parametric study is presented to show the effects of the printed resistors on impedance matching and insertion loss. A prototype of the proposed power divider is fabricated. Measurement results are compared with the simulated ones. The results show a good agreement. An insertion loss of 11 - 15 dB, which is 2 - 5 dB more than the ideal case, is achieved over a frequency band of 0.5 to 25 GHz.