Abstract: Provided is a parabolic antenna that suppresses leakage of radio waves with a simpler configuration. The parabolic antenna includes a horn that transmits and receives signals; a feed that supports the horn and relays the signals the horn transmits and receives; a reflector that reflects the received signals to focus the received signals on the horn and reflects the signals from the horn to transmit the signals; a reflecting mirror supporting member that supports the reflector; and a feed fitting adapter that enables the feed to be fitted into the reflecting mirror supporting member. A choke groove is formed in at least one of a joint area between the reflecting mirror supporting member and the reflector and a joint area between the reflecting mirror supporting member and the feed fitting adapter, which suppresses propagation of radio waves traveling through the gap of the joint area.

Abstract: Provided is a parabolic antenna that suppresses leakage of radio waves with a simpler configuration. The parabolic antenna includes a horn that transmits and receives signals; a feed that supports the horn and relays the signals the horn transmits and receives; a reflector that reflects the received signals to focus the received signals on the horn and reflects the signals from the horn to transmit the signals; a reflecting mirror supporting member that supports the reflector; and a feed fitting adapter that enables the feed to be fitted into the reflecting mirror supporting member. A choke groove is formed in at least one of a joint area between the reflecting mirror supporting member and the reflector and a joint area between the reflecting mirror supporting member and the feed fitting adapter, which suppresses propagation of radio waves traveling through the gap of the joint area.

Abstract: The present invention provides a waveguide coupler capable of attaining high electrical characteristics and high productivity. The waveguide coupler 10 of the present invention includes four ports 1 to 4, and grooves 21 to 24 provided along a waveguide wall in the vicinity of a joint. The grooves 21 and 22 are formed along inner walls and the grooves 23 and 24 are formed along outer walls. By forming grooves along the waveguide wall, the same function as a case where a ridge exists in the vicinity of the joint can be served and therefore bandwidth of various frequency characteristics can be widened, thus attaining high electrical characteristics in various frequency menus. Further, cutting grooves provides higher manufacturing workability than forming a ridge and increase the way of grooving, thereby attaining high cost performance and high productivity.

Abstract: A wavegide hybrid junction includes a coupling section, a coupling hole, and an external cavity resonator. The coupling section is formed by removing by a predetermined length part of a common narrow side wall for isolating two rectangular waveguides. The coupling hole is formed in the upper wall of a waveguide so as to communicate with the coupling section. The external cavity resonator externally cover the coupling hole.