TELESCOPIC AERIAL SYSTEM FOR PORTABLE TRANSCEIVER

摘要

An antenna for a portable cellular telephone (100) includes a quarter-wavelength ground radiator (106) and a helical coil (104) capacitively coupled to an extendable half-wavelength radiator (102). The extendable half-wavelength radiator (102) includes a metallic coil (209) molded in plastic. The ground radiator (106) includes a serpentined transmission line (302) on a flexible circuit board (310). The helical coil (104) and ground radiator (106) are coupled by a transmission line (110) to a duplexer (112). The duplexer couples transmitter signals from a radio transmitter (114) to the antenna and receiver signals from the antenna to a radio receiver (116). The antenna may be advantageously utilized in any portable radio applications where small size and immunity to hand induced radiation losses are desired.