A slim television broadcast receiver employing antennas in which a waveguide is formed by a metallic plate and a copper foil on a printed circuit board. An insulating magnetic element is loaded so as to block one of a pair of aperture planes of the waveguide, and the aperture area is enlarged by beveling the other aperture plane. Tuning elements are provided on opposed sides with respect to the center part of the other aperture, which antennas are placed on opposed side ends of the slim television broadcast receiver, thereby performing electronic tuning and phase synthesis diversity reception.