Millimetre-wave broadband waveguide-based power combiner using lossy planar lines

A lossy waveguide-based power combiner is proposed for broadband low-loss symmetrically combining with good port matching and isolation at millimetre-wave frequencies. In the combiner, lossy planar transmission lines are used to provide attenuation to even-mode excitations and to achieve broadband low-loss power combining with good port matching and isolation. The experimental results show that the lossy waveguide-based power combiner has a loss of about 0.14 dB and a reflection coefficient and isolation of about -15 dB in 26.5-40 GHz, respectively. The lossy waveguide-based power combiner can be used in a multi-way power amplifying-combining system to obtain millimetre-wave broadband high solid-state power with high efficiency and good stability.