Dielectrically loaded antenna and a handheld radio communication unit including such an antenna

摘要: A miniature antenna for operation at frequencies in excess of 200 MHz has a ceramic core the form cylindrical rod having relative dielectric constant greater than 5. Plated on outer surfaces is an element structure comprising single pair oppositely disposed helical elements common central axis coincident with core. At distal end antenna, they are connected to coaxial feeder passing axially through core, and their proximal ends rim trap conductor which, coupled screen structure. operating frequency, behaves as loop, radiation response nulls directed generally perpendicularly each side plane containing connections 6 conductive sleeve. The intended primarily handheld communication unit such cellular or cordless telephone handset, presence pattern reducing into user's head.