To provide a waveguide antenna capable of widening a specific band to about three times as wide as the conventional one without increasing the sectional area of a waveguide.
In a metal waveguide 101 which has one end 102 short-circuited and also has the other end 103 made open or provided with a slot, an inter-layer metallic plate 104 is provided for constituting a multilayer structure which is divided into two layer groups. The resonance frequencies of respective layers are made different and resonance frequencies of the two layer groups A and B are disposed alternately on a frequency axis. Electric power is supplied individually to the two layer groups A and B so that electric fields of the two layer groups are in opposite directions at the waveguide open end 103.
OTA SHINMEI
MATSUMOTO KOZO
Mitsuo Tanaka
Kawabata Junichi