MULTIBAND MULTIMODE COMPACT ANTENNA SYSTEM

摘要

An antenna system for use in a communications device, such as a mobile phone. The antenna system has a multiband GSM antenna operating at GSM850, GSM900, GSM 1800 and GSM 1900 that has a short-circuited section located between a separate UMTS antenna and a UMTS receive diversity antenna. As such, large electrical isolation between the two UMTS antennas can be achieved. The UMTS antennas can be short-circuited microstrip loop antennas, IFA, PIFA, ILA or PILA antennas. These antennas are well-isolated antennas instead of coupled antennas. As such, the diversity antenna is well isolated from the main antenna despite its close proximity to the main antenna. Well-isolated antennas have little mutual coupling and, therefore, are easier to design than coupled antennas, because isolated antennas can be tuned independently from each other.