Multiple-frequency antenna device

A multiple-frequency antenna device, adapted to be electrically connected to a radio-frequency (RF) circuit, said multiple-frequency antenna device comprising:

• an antenna unit including
• an insulating substrate, and
• a first conductive layer and a second conductive layer that are disposed on said insulating substrate, said first conductive layer being electrically connected to ground via a first ground line, and being further electrically connected to the RF circuit via a feeding line, said second conductive layer being electrically connected to ground via a second ground line;
• and
• a frequency switch unit including
• a first frequency adjustment component electrically connected to ground,
• a second frequency adjustment component electrically connected to ground, and
• a switching component that is switchable at least to a first state and to a second state,
• wherein, when said switching component is switched to the first state, said first frequency adjustment component is electrically connected to said antenna unit via said switching component and the second ground line, and said antenna unit and said frequency switch unit are cooperatively resonant at a first resonant frequency,
• wherein, when said switching component is switched to the second state, said second frequency adjustment component is electrically connected to said antenna unit via said switching component and the second ground line, and said antenna unit and said frequency switch unit are cooperatively resonant at a second resonant frequency different from the first resonant frequency.

A multiple-frequency antenna device, adapted to be electrically connected to a radio-frequency (RF) circuit, said multiple-frequency antenna device comprising:

• an antenna unit including
• an insulating substrate, and
• a first conductive layer, a second conductive layer and a third conductive layer that are disposed on said insulating substrate, said first conductive layer and said second conductive layer being electrically connected to ground respectively via a first ground line and a second ground line, said third conductive layer being electrically connected to the RF circuit via a feeding line that is electrically connected to ground via a third ground line;
• and
• a frequency switch unit electrically connected to said antenna unit in parallel via the second ground line and the feeding line, and including
• a first frequency adjustment component electrically connected to said antenna unit via the second ground line, and
• a switching component that is switchable to a first state and to a second state,
• wherein, when said switching component is switched to the first state, said first frequency adjustment component is electrically connected to said antenna unit via said switching component and the feeding line, said antenna unit and said frequency switch unit are cooperatively resonant at a first resonant frequency, and said antenna unit is individually resonant at a second resonant frequency different from the first resonant frequency, and
• wherein, when said switching component is switched to the second state, said first frequency adjustment component is electrically disconnected from the feeding line, said antenna unit and said frequency switch unit are cooperatively resonant at a third resonant frequency different from the first and second resonant frequencies, and said antenna unit is individually resonant at a fourth resonant frequency different from the first, second and third resonant frequencies.

A multiple-frequency antenna device, adapted to be electrically connected to a radio-frequency (RF) circuit, said multiple-frequency antenna device comprising:

• an antenna unit and a frequency switch unit;
• said antenna unit including
• an insulating substrate, and
• a first conductive layer, a second conductive layer and a third conductive layer that are disposed on said insulating substrate, said first conductive layer being electrically connected to ground via a first ground line, said second conductive layer being electrically connected to ground via a second ground line, said third conductive layer being electrically connected to the RF circuit via a feeding line that is electrically connected to ground via a third ground line;
• said frequency switch unit including
• a first frequency adjustment component electrically connected to ground,
• a second frequency adjustment component electrically connected to ground, and
• a switching component that is switchable to a first state and to a second state,
• wherein, when said switching component is switched to the first state, said first frequency adjustment component is electrically connected to said antenna unit via said switching component and the second ground line, said antenna unit and said frequency switch unit are cooperatively resonant at a first resonant frequency, and said antenna unit is individually resonant at a second resonant frequency different from the first resonant frequency, and
• wherein, when said switching component is switched to the second state, said second frequency adjustment component is electrically connected to said antenna unit via said switching component and the second ground line, said antenna unit and said frequency switch unit are cooperatively resonant at a third resonant frequency different from the first and second resonant frequencies, and said antenna unit is individually resonant at a fourth resonant frequency different from the first, second and third resonant frequencies.