| 摘要 |
<p>#CMT# #/CMT# The array has an interconnection unit for connecting two consecutive antennas of the array to supply one of the antennas with a power non radiated by the other antenna. Each antenna has a metallic ground plane (PM1) inserted horizontally near and below a ground surface (S). A metallic excitation line (LE1) extends rectilinearly and parallely above the ground plane and the ground surface for radiating ground waves. The unit has an underground return line (LR) and a transformer. #CMT#USE : #/CMT# Ground wave antenna array for emitting progressive kilometric or hectometric waves in an average or low frequency band ranging between 10 kilo hertz and 3 mega hertz for broadcasting a digital radio program. #CMT#ADVANTAGE : #/CMT# The metallic ground plane is inserted horizontally near and below the ground surface, thus enabling the antenna to be invisible and discreet in urban environment, while being insensitive to violent wind, blow, lightning, quake or explosion. The array can be integrated in a landscape, and facilitates the propagation of the ground wave along a privileged direction. The metallic ground plane ensures better electrical continuity between constitutive elements of the plane. The antenna array has a wide bandwidth even at low frequencies in order to allow the digital broadcasting and multiplexing of the radio programs from a single site. The metallic ground plane can be constructed in an easier and inexpensive manner, and resists against chemical attacks in the natural environment such as earth. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a schematic vertical front view of an array comprising two antennas connected with each other. ET : Termination element LE1, LE2 : Metallic excitation lines LR : Underground return line PM1, PM2 : Metallic ground planes S : Ground surface.</p> |
