An antenna can efficiently radiate at both the lower cell phone frequency band of about 850 MHz and the higher cell phone frequency band of about 1920 MHz that are in current use. The antenna includes a vertical conductor with an upper portion (32) of a length that is about 1/2 wavelength at the lower frequency to effectively radiate at that frequency. An upper PRD (phase reversal device) (40) located along the upper conductor portion divides it into top and bottom parts (60, 70) each of about 1/2 wavelength at the higher frequency, the PRD providing a 180.degree. phase reversal at the higher frequency without affecting the lower frequency. A lower conductor portion (34) includes a coil (80) that produces a phase reversal at the lower frequency, a lower PRD (82), and a short straight conductor part (84). A lower conductor part (90) extends through the lower PRD (82) and connects through a mount member (130) to a coaxial feed.
The present invention is aimed to provide an external antenna to adapt to the wireless communication device for receiving and transmitting signals by means of double attachable functions (magnetic/on glass/patch). The external antenna is portable and retractable, and easy to assemble and detach.An external antenna comprises a base, a connector is disposed on the proximal end of the base, an antenna fits into the connector, a metal cap is disposed under the distal end of the base, a magnet fits in the metal cap, a sucking disk disposed under the magnet screwed into the cap, a conductor is extended between said base and a coaxial connector, thus they are combined to form an external antenna.The external antenna can be attached to a flat surface of objects by sucking disk or magnet.
A wide receiving range antenna is disclosed to include a holder base, and a resonator unit connected to one end of the holder base for receiving signal, which the resonator unit having a barrel connected to the holder base, a metal block spaced from the barrel at a predetermined distance and connected to a coaxial cable being inserted through the holder base, and a plurality of resonators axially extended from one side of the metal block opposite to the coaxial cable for receiving signals of different frequencies and transmitting received signals to an electronic device through the coaxial cable.
