An $X$ -Band Lumped-Element Wilkinson Combiner With Embedded Impedance Transformation

An integrated equal-split Wilkinson power combiner/divider tailored for operation in the X-band is reported in this letter. The combiner features differential input/output ports with different characteristic impedances, thus embedding an impedance transformation feature. Over the frequency range from 8 to 14 GHz it shows insertion loss of 1.4dB, return loss greater than 12 dB and isolation greater than 10 dB. It is implemented in a SiGe bipolar technology, and it occupies an area of 0.12 mm
²
.