A Novel Frequency-Selective Power Combiner/Divider in Single-Layer Substrate Integrated Waveguide Technology

A frequency-selective power combiner/divider in single-layer substrate integrated waveguide (SIW) technology is introduced. The basic building block consists of a planar four cavity structure with three of them operated in SIW TE₁₀₁ modes and one in SIW TE₂₀₁ mode. Each cavity is coupled to one port of the unit. In addition the overall configuration considers couplings of each resonator to the two adjacent ones. Due to the coupling transformation properties of the TE₂₀₁ mode cavity, second order 3 dB transfer functions are obtained from each port to two adjacent ones while the fourth port is almost isolated. The novel combiner/divider is designed for 11 GHz and prototyped on RT/Duroid 5870 substrate. Measurements verify the design process and operation of the device.