Abstract: A biconical antenna for ultra broad-band linear polarization operation in which capacitive sleeve VSWR tuning is effected between the apex regions of the two cones and zig-zag substantially V-shaped spokes are provided conically diverging from the cone base peripheries.

Abstract: A television broadcast antenna includes a high-gain pylon consisting of a vertical array of slots in a conductive cylinder for radiating with high gain towards distant locations. An auxiliary low-gain vertically-polarized portion of the antenna has its phase center coincident with or near the phase center of the pylon for radiating a vertically polarized signal component. This position of the auxiliary portion reduces wind load and feed-line length by comparison with a location above the pylon. In a particularly advantageous embodiment of the invention, the horizontally-polarized radiation pattern of the pylon in the region within a few degrees below the main beam, which is the region directed towards local television viewers, has a low but relatively constant amplitude and phase.

Abstract: A slotted-cylinder antenna especially adapted for television broadcasting use radiates a circularly-polarized pattern. Each radiating slot is associated with an elongated conductive parasitic radiator in close proximity to the slot for good power coupling therebetween. The parasitic radiator is almost but not quite parallel with the slot (preferably being at a six degree orientation with the slot), so that energy is coupled into the parasite and reradiated almost vertically polarized. The combination of the radiated field of the slot and reradiated field of the parasite is made circularly polarized by selection of that length of the parasite which gives the correct phase-shift.

Abstract: A broad-band antenna device comprising a variable aperture element which radiates or receives signals in the high frequency portion of the band and a pair of fixed aperture elements which radiate or receive signals in the low frequency portion, the variable aperture element comprising a planar spiral antenna element with a double winding which is electrically coupled to the fixed aperture elements comprising a pair of oppositely positioned center fed slot antenna elements.