Multiband planar built-in radio antenna with inverted-L main and parasitic radiators

摘要

A multi-band radio antenna device (1) for a radio communication terminal, comprising a flat ground substrate (20), a flat main radiating element (2, 9) having a radio signal feeding point (3), and a flat parasitic element (5, 6). The main radiating 5 element is located adjacent to and in the same plane as said ground substrate, and preferably dielectrically separated therefrom. The antenna device is suitable for being used as a built-in antenna in portable radio terminals, such as a mobile phone (30).