Multi-band antenna

A multi-band antenna with a high frequency operating band and a low frequency operating band, comprising:

• a radiating element, having a feed-in point for transmitting signals and a plurality of radiation arms, wherein the radiation arms comprise:
• a first radiation arm, coupled to the feed-in point, having a first resonant mode;
• a second radiation arm, coupled to the feed-in point, having a second resonant mode, wherein the first resonant mode and the second resonant mode jointly generate the high frequency operating band;
• and
• a third radiation arm, coupled to the feed-in point, having a third resonant mode for generating the low frequency operating band;
• a grounding plane, having a grounding point;
• a short-circuiting element, for coupling the radiating element to the grounding plane:
• and
• a short-circuiting regulator, wherein the short-circuiting regulator is coupled to the grounding plane and forms a gap to enhance the impedance matching of the multi-band antenna under both the high frequency operating band and the low frequency operating band.

A notebook computer comprising:

• a shielding metal, for reducing electromagnetic interference;
• and
• a multi-band antenna, having a high frequency operating band and a low frequency operating band, the antenna comprising:
• a radiating element, having a feed-in point for transmitting signals and a plurality of radiation arms, wherein the radiation arms comprise:
• a first radiation arm, coupled to the feed-in point, having a first resonant mode;
• a second radiation arm, coupled to the feed-in point and having a second resonant mode, wherein the first resonant mode and the second resonant mode jointly generate the high frequency operating band, and the operating bandwidths of the first radiation arm and the second radiation arm are different and partially overlap each other;
• and
• a third radiation arm, coupled to the feed-in point and having a third resonant mode for generating the low frequency operating band;
• a grounding plane, coupled to the shielding metal and having a grounding point;
• and
• a short-circuiting element, for coupling the radiating element to the grounding plane, wherein the short-circuiting element, the grounding point, the first radiation arm, the second radiation arm and the third radiation arm are folded up.

A notebook computer comprising:

• a shielding metal, for reducing electromagnetic interference;
• and
• a multi-band antenna, having a high frequency operating band and a low frequency operating band, the antenna comprising:
• a radiating element, having a feed-in point for transmitting signals and a plurality of radiation arms, wherein the radiation arms comprise:
• a first radiation arm, coupled to the feed-in point, having a first resonant mode;
• a second radiation arm, coupled to the feed-in point and having a second resonant mode, wherein the first resonant mode and the second resonant mode jointly generate the high frequency operating band;
• and
• a third radiation arm, coupled to the feed-in point and having a third resonant mode for generating the low frequency operating band;
• a grounding plane, coupled to the shielding metal and having a grounding point;
• a short-circuiting element, for coupling the radiating element to the grounding plane;
• and
• a short-circuiting regulator, wherein the short-circuiting regulator is coupled to the grounding plane and forms a gap to enhance the impedance matching of the multi-band antenna under both the high frequency operating band and the low frequency operating band.