Title :
A diversity antenna for very small 800-MHz band portable telephones
Author :
Ogawa, Koichi ; Uwano, Tomoki
Author_Institution :
Components & Devices Res. Center, Matsushita Electr. Ind. Co. Ltd., Osaka, Japan
fDate :
9/1/1994 12:00:00 AM
Abstract :
A diversity antenna comprising a short whip antenna top loaded with a small cylinder and a new built-in antenna has been developed for very small portable telephones in the 800-MHz band. Wire-grid analyses and whip antenna experiments yielded good radiation characteristic results when the equivalent electrical length of the whip antenna equalled a half wavelength. The built-in antenna features extreme compactness, its size being one-third that of a conventional planar inverted-F antenna. The characteristics were investigated experimentally, and an antenna of 3.5 cc volume with a gain of -1 dBd and a bandwidth of 30 MHz was designed at 879 MHz. Finally, the diversity characteristics were subjected to field measurements and a diversity correlation of 0.26 was obtained
Keywords :
antenna radiation patterns; antenna testing; cellular radio; diversity reception; mobile antennas; mobile radio systems; radiotelephony; -1 dB; 30 MHz; 800 MHz; 879 MHz; UHF; bandwidth; built-in antenna; diversity antenna; diversity characteristics; diversity correlation; equivalent electrical length; field measurements; gain; half wavelength; portable telephones; radiation characteristics; short whip antenna; small cylinder; top loaded antenna; whip antenna experiments; wire-grid analyses; Antenna measurements; Antennas and propagation; Bandwidth; Diversity reception; Loaded antennas; Microstrip antennas; Planar arrays; Receiving antennas; Telephony; Transmitting antennas;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
