Research and design of the millimeter wave power equalizer using waveguide on Ka-band

A power or gain equalizer is often used to smooth the gain curve when they using as the input port of Traveling Wave Tubes (TWT) or High Power Solid State Amplifiers. But the TWT had a big gain fluctuation in the working frequency. Generally, coaxial resonance cavity with electromagnetic wave absorber and micro strip resonance cavity with thin film resistance compose the equalizer. But they often used on lower millimeter such as X wave band, because they have many disadvantages in millimeter wave. One coaxial resonator will generate more than one resonating frequencies and micro strip resonance cavity has high insertion loss and low Q value. In this paper, a novel structure with H-plane full-height waveguide resonance cavity on the narrow-wall to fulfill a millimeter wave power or gain equalizer has been equalized.