A DUAL-BAND ANTENNA COUPLER FOR CELLULAR AND PCS APPLICATIONS

摘要

In today's fast-growing cellular phone systems throughout the world the amount of congestion, especially in urban areas, is becoming a significant issue. Major system providers are scrambling to find adequate solutions to the problem. The original cellular frequency band (890 to 915 MHz GSM in Europe) was later expanded by 10 MHz to 880 to 915 MHz to help ease the traffic load. This expanded band is known as extended GSM. Now even that band is full and the choice is to go to the higher assigned 1850 to 1910 MHz PCS band in the US and the 1710 to 1880 MHz DCS-1800 band in Europe.