Abstract: A multiband antenna structure comprises a substrate, a first radiating unit and a second radiating unit. The first radiating unit is disposed on the substrate, having a feed-in end, a first radiating path and a first terminal. The first radiating unit is operated at a first operating frequency. The second radiating unit is disposed on the substrate and has a grounding end, a second radiating path and a second terminal. The second radiating unit is operated at a second operating frequency. The first terminal of the first radiating unit is adjacent to the second radiating path or the second terminal of the second radiating unit is adjacent to the first radiating path for the first radiating unit or the second unit to excite a third operating frequency. The third operating frequency is lower than the lower frequency among the first operating frequency and the second operating frequency.

Abstract: An antenna structure, used for being fed with a signal, includes a grounding portion, a radiation portion, and a frequency adjusting portion. The radiation portion has a loop segment, a high frequency segment, and a low frequency segment. The loop segment has a feeding sub-segment adjacent to the grounding portion and used for being fed with the signal. The high and low frequency segments are extended from opposite ends of the loop segment away from each other. The frequency adjusting portion is connected to the loop segment and the grounding portion. A high frequency dual-path is formed from a feeding point of the feeding sub-segment and extends along the loop segment in two different directions to the high frequency segment. A low frequency dual-path is formed from the feeding point and extends along the loop segment in two different directions to the low frequency segment.

Abstract: A radio frequency identification (RFID) device includes a metallic antenna plate, a first metallic tube, and a second metallic tube. The metallic antenna plate has a positioning portion and defines a central axis, a first hole, and a second hole. The positioning portion is formed in the path of the central axis and surrounds the second hole. The first and second metallic tubes are disposed on the metallic antenna plate. The first and second metallic tubes each has one end disposed on the positioning portion. The first and second metallic tubes extend across the first and second holes, respectively and are welded to the metallic antenna plate. The portion of the second metallic tube that extends across the second hole is approximately perpendicular to the portion of the first metallic tube that extends across the first hole.

Abstract: A multiband antenna structure comprises a substrate, a first radiating unit and a second radiating unit. The first radiating unit is disposed on the substrate, having a feed-in end, a first radiating path and a first terminal. The first radiating unit is operated at a first operating frequency. The second radiating unit is disposed on the substrate and has a grounding end, a second radiating path and a second terminal. The second radiating unit is operated at a second operating frequency. The first terminal of the first radiating unit is adjacent to the second radiating path or the second terminal of the second radiating unit is adjacent to the first radiating path for the first radiating unit or the second unit to excite a third operating frequency. The third operating frequency is lower than the lower frequency among the first operating frequency and the second operating frequency.

Abstract: A radio frequency identification (RFID) device includes a metallic antenna plate, a first metallic tube, and a second metallic tube. The metallic antenna plate has a positioning portion and defines a central axis, a first hole, and a second hole. The positioning portion is formed in the path of the central axis and surrounds the second hole. The first and second metallic tubes are disposed on the metallic antenna plate. The first and second metallic tubes each has one end disposed on the positioning portion. The first and second metallic tubes extend across the first and second holes, respectively and are welded to the metallic antenna plate. The portion of the second metallic tube that extends across the second hole is approximately perpendicular to the portion of the first metallic tube that extends across the first hole.

Abstract: An antenna structure, used for being fed with a signal, includes a grounding portion, a radiation portion, and a frequency adjusting portion. The radiation portion has a loop segment, a high frequency segment, and a low frequency segment. The loop segment has a feeding sub-segment adjacent to the grounding portion and used for being fed with the signal. The high and low frequency segments are extended from opposite ends of the loop segment away from each other. The frequency adjusting portion is connected to the loop segment and the grounding portion. A high frequency dual-path is formed from a feeding point of the feeding sub-segment and extends along the loop segment in two different directions to the high frequency segment. A low frequency dual-path is formed from the feeding point and extends along the loop segment in two different directions to the low frequency segment.

Abstract: The instant disclosure relates to a multi-band antenna structure for accepting a feed signal. The antenna structure includes a grounding portion, a radiating portion, and a tuning portion. The radiating portion is spaced apart from the grounding portion and disposed on one side thereof. The radiating portion has a first and a second radiating segments interconnected perpendicularly. The tuning portion is connected between the first radiating segment and the grounding portion. The tuning portion has a hairpin segment and a grounding segment. The hairpin segment is substantially U-shaped and one end thereof is connected to one end of the first radiating segment proximate to the grounding portion. The opposite ends of the grounding segment are connected to the other end of the hairpin segment and the grounding portion. The connecting location between the first radiating segment and the hairpin segment is used for accepting the feed signal.