High‐Q High‐Isolation Resistor‐Less Filtering Power Dividing SIW‐Cavity for High‐Power Applications

ABSTRACT A high‐power resistor‐less filtering power divider is proposed in this paper. It consists of a substrate‐integrated‐waveguide (SIW) cavity resonator, with two centered posts in it. Two high unloaded quality factor () evanescent‐modes, mode 1 and mode 2, are excited at different resonant frequencies. The posts are loaded with two capacitive loads, () and (), embedded in the structure. Controlling these capacitances, the resonant frequency of the proposed power divider is tuned. Moreover, the resonant frequency of mode 2 is shifted to its equivalent of mode 1, obtaining an isolation between the output ports. The proposed power divider is designed to operate at 4.5 GHz. A good agreement is obtained between the simulated and the measured results. The proposed SIW‐cavity has a size of () without its feeding lines. A filtering bandwidth of 166 MHz and a 528 MHz 20‐dB roll off bandwidth, are measured. Also, a high unloaded quality factor of 296 is obtained. Moreover, a measured insertion loss and an isolation of 0.9 dB and 32 dB are achieved, respectively. The proposed resistor‐less SIW‐cavity power divider is suitable to operate with high‐power applications up to 10 Watts, due to its capability to handle high input power levels.