S-band cavity filtering coupler

The utility model relates to an S-waveband cavity filtering coupler. The coupler comprises a shell square frame and a coupling circuit board which is arranged in the shell square frame and is parallelto the frame surface of the shell square frame, a glass insulator assembly for inputting and outputting a radio frequency signal and a coupling signal is arranged on one side of the square frame of the shell; cover plates are fixedly arranged on the front surface and the back surface of the square frame of the shell; the shell square frame and the cover plate form a closed inner cavity structure;a plurality of sections of 1/4 lambda uniform impedance resonance columns are sequentially arranged in parallel on the front surface of the coupling circuit board along the width direction of the coupling circuit board; the 1/4 lambda uniform impedance resonance column close to the glass insulator assembly is connected with the glass insulator assembly; two sections of microstrip lines are arranged in parallel on the back