A gain equalizer operating on Ku-band based on dual-mode square substrate integrated waveguide (SIW) resonators are designed according to miniaturization and high

Q

-factor.Two orthogonal coupling slots are designed to excite degenerate modes (TE

201

and TE

102

) in a square cavity; two perturbation metal holes in the vertical direction are employed to perturb TE

102

mode to tune resonant frequency easily for fitting a target curve.The positions of the film resistors loaded on cavity are investigated to realize attenuations and

Q

-factor of the dual-mode tuning independent.The frequency offsets and tune of the resonant of the dual-mode cavity af

ter the two resonant cavities cascaded are analyzed.Analysis and design method of the proposed equalizer based on dual-mode resonators are presented.Compared with equalizer based on single mode resonators

the proposed equalizer keeps the original performance

and has smaller size for reducing by half the number cavities.The measured results and simulated results are matched well

and the maximum error is 0.4dB.