| 摘要 |
PURPOSE:To attain the miniaturization of a circuit with its constitution simplified and to reduce the loss of the circuit by exciting a cavity resonator type filter to polarize wave circularly and by allowing a waveguide section connected to this filter to operate circular polarization. CONSTITUTION:Cavity resonator type filters 31...34 can propagate circular polarized waves and electromagnetic waves of filters 31...34 are excited in section 21 through slots 41...44 provided to the wall of waveguide section 21. Slot 51 is a coupling hole provided between rectangular waveguide 61 and filter 31, the propagation mode of electromagnetic waves inside of waveguide 61 is mode TE10 which is a basic mode, and coupling hole 51 generates circular polarized waves inside of filter 31 through electromagnetic coupling. Then, filters 31...34 are three-stage cavity resonators making use of mode TE11 and excited as they are into section 21 and at this time, resonance frequencies of filters 31...34 are adjusted into different passing frequencies to enable filters to obtain high impedance values at frequencies except passing frequencies. Consequently, the miniaturization of a circuit with its constitution simplified can be realized and its loss can also be reduced. |
