Adjustable multi-band antenna
First Claim
1. An adjustable multi-band antenna having a ground plane, a radiating plane with a dielectric support part, a feed conductor and a short conductor of the antenna, and an adjusting circuit to displace operation band of the antenna, which adjusting circuit comprises a parasitic element and a switch as well as a terminal element directly connected to the ground plane, by which switch the parasitic element can be connected to the terminal element;
- the adjusting circuit further comprising, for restricting the effect of controlling the switch to a single operation band of the antenna, a filter located electrically in series with the parasitic element and the switch.
4 Assignments
0 Petitions
Accused Products
Abstract
An adjustable multi-band planar antenna especially applicable in mobile terminals. In the structure of the antenna, advantageously on a surface of a dielectric part, there is placed a conductive element (430) having a significant electromagnetic coupling to the radiating plane (422). The arrangement further comprises a filter (440) and a switch (SW) so that the parasitic conductive element at issue can be connected through the filter to a terminal element (TE) connected to the ground plane. That terminal element is pure short-circuit or a reactive element. An antenna'"'"'s operation band, which is desired to be displaced, situates on pass band of the filter, and another operation band, which is desired not to be effected, situates in stop band of the filter. Controlling the switch causes the electric length of the antenna'"'"'s part corresponding for example the upper operation band to change measured from the short-circuit point, in which case also the resonance frequency changes and the band is displaced. Only one operation band of the antenna is affected because on the other operation bands a high impedance is “seen” from the parasitic element towards the ground, although the switch is closed.
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Citations
9 Claims
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1. An adjustable multi-band antenna having a ground plane, a radiating plane with a dielectric support part, a feed conductor and a short conductor of the antenna, and an adjusting circuit to displace operation band of the antenna, which adjusting circuit comprises a parasitic element and a switch as well as a terminal element directly connected to the ground plane, by which switch the parasitic element can be connected to the terminal element;
the adjusting circuit further comprising, for restricting the effect of controlling the switch to a single operation band of the antenna, a filter located electrically in series with the parasitic element and the switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A radio device having an adjustable multi-band antenna, which comprises a ground plane, a radiating plane and an adjusting circuit to displace operation band of the antenna, which adjusting circuit comprises a parasitic element, a switch and a terminal element directly connected to the ground plane, by which switch the parasitic element can be connected to the terminal element;
the adjusting circuit further comprising, for restricting the effect of controlling the switch to a single operation band of the antenna, a filter located electrically in series with the parasitic element and the switch.
Specification