Multi-band antenna device for radio communication terminal and radio communication terminal comprising the multi-band antenna device

A multi-band radio antenna device for a radio communication terminal, comprising

• a substrate, and
• a radiating antenna element thereon having a radio signal feeding point, said radiating antenna element comprising:
• a first radiating portion resonant at a first frequency band,
• said first radiating portion comprising:
• an elongate substantially straight radiating portion arranged proximal to and connected to said signal feeding point, and a tightly meandered radiating portion arranged distal from said radio signal feeding point and connected to said substantially straight radiation portion, said straight radiation portion and said meandered radiation portion forming an antenna having said first resonance frequency;
• wherein
• a second radiating portion connected as a branch to said first radiating portion at a bifurcation position thereof arranged distal from said radio signal feeding point, whereby said first radiation portion and said second radiation portion form a combined antenna having a second resonance frequency in which the second frequency is approximately twice the first frequency, wherein
• said antenna having said first resonance frequency operates as a quarter-wavelength antenna, and
• said combined antenna having said second resonance frequency operates as a three-quarter-wavelength antenna with the second resonance frequency lowered by said second radiating portion by electrically coupling to the first radiating portion.