DIRECTIONAL COUPLER AND DIRECTIONAL COUPLING METHOD

摘要

Input port 101 is connected to output port 102 via open-circuited stub 107, first transmission line 105 and open-circuited stub 108. Coupling port 103 is connected to isolation port 104 via second transmission line 106 in electromagnetic coupling with first transmission line 105. Open-circuited stubs 107 and 108 have a stub length corresponding to 1/4 wavelength in desired stop frequency. It is thereby possible to provide a directional coupler and directional coupling method enabling the miniaturization and harmonic spurious suppression effect with a low loss and with excellence even in microwave/millimeter wave band. <IMAGE>