DoCoMo announces prototype for true global roaming phone with eight frequency bands able to connect between 700 MHz and 2.5 GHz — PR Here
The end of roaming issues.. imagine what else the next decade holds in store..
NTT DOCOMO, INC. announced today that it has developed a prototype multi-band power amplifier that accommodates eight frequency bands between 700 MHz and 2.5 GHz, paving the way for lightweight, all-in-one mobile phones capable of standalone wireless communications of different standards, including the forthcoming extra-fast LTE standard as well as existing W-CDMA and GSM.
Power amplifiers are used in mobile phones to increase signal power up to levels required for wireless communication.
As conventional multi-band phones must employ a separate single-band amplifier for each band, the sizes of these phones will inevitably increase to accommodate new frequency bands for LTE services being launched in markets worldwide, including Japan.
DOCOMO’s new amplifier, which offers gain and output power equivalent to those of conventional single-band amplifiers, paves the way for multi-standard mobile phones that are generally no larger than existing models. It enables 8-band operation by employing matching circuits whose frequency characteristics are controlled by multiple semiconductor switches according to the required frequency band.