Progress of multiband antenna ...

Progress of multiband antenna technology in mobile phone industryProgress of multiband antenna technology in mobile phone industry
Zhinong Ying Sony-Ericsson Mobile Communications AB, Nya Vattertornet, SE-221 83 Lund, Sweden E-mail:ying.zhinong@sonyericsson.com

Summary
In the 1990’s, the mobile phone industry experienced a dramatic development. The first stage was from analog standard to digital standard development, for example, analog standard such as AMPS (Advanced Mobile Phone System), NMT (Nordic Mobile Telephone) and ETACS; digital standard such as GSM, D-AMPS and CDMA. The second stage was from single band to multi-band due to the strong capacity requirements. DCS1800 and PCS1900 were introduced in the middle of 1990’s. Ying first proposed a dual band non-uniform helical antenna as shown in Fig. 1 [1, 2], which became later a popular antenna for