Patent ID: 8290453

Claim:
A power combiner for combining a plurality of differential signals to an unbalanced signal, comprising a first balun and a second balun, the first balun including: a first line having a first grounded end and a first end connected to a positive input of a first differential input signal; a second line having a second grounded end and a second end connected to a negative input of the first differential input signal; a third line formed in parallel with the first line, the third line having a first opened end corresponding to the first grounded end of the first line and a third end corresponding to the first end of the first line; and a fourth line formed in parallel with the second line, the fourth line having a fourth end corresponding to the second grounded end of the second line and a fifth end corresponding to the second end of the second line and connected to the third end of the third line, the fourth end being connected to a single-ended output end for outputting the unbalanced signal with respect to the ground, and the second balun including: a fifth line having a third grounded end and a sixth end connected to a positive input of a second differential input signal; a sixth line having a fourth grounded end and a seventh end connected to a negative input of the second differential input signal; a seventh line formed in parallel with the fifth line, the seventh line having a second opened end corresponding to the third grounded end of the fifth line and an eighth end corresponding to the sixth end of the fifth line; and an eighth line formed in parallel with the sixth line, the eighth line having a ninth end corresponding to the fourth grounded end of the sixth line and connected to the fourth end of the fourth line and a tenth end corresponding to the seventh end of the sixth line and connected to the eighth end of the seventh line.