US Patent 9093731 Combiner for an RF power amplifier

Embodiments of the invention include a combiner for an RF amplifier comprising wiring and a transmission line transformer. The transmission line transformer may include a ferrite core having a hole defined therein; a coaxial cable having a first dielectric constant and routed through the hole of the ferrite core; and a stripline having a second dielectric constant and routed around the ferrite core. In some embodiments, an electrical length of the stripline is matched to an electrical length of the coaxial cable. The electrical length of the coaxial cable may be defined by the first dielectric constant and the electrical length of the stripline may be defined by the second dielectric constant.