ANTENNA DEVICE

An antenna device applied in a headset device, includes a circuit board, an antenna body and a metal cover. The circuit board includes a flexible circuit board. The antenna body is mounted to the circuit board and electrically connected with the flexible circuit board. The metal cover covers and adjacent to the antenna body and the circuit board. The antenna body is coupled with the metal cover to motivate each other to make the antenna body and the metal cover respectively become a first radiating element and a second radiating element so as to reach a radiating purpose. So a better radiating effect of the antenna device is realized.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an antenna, and more particularly to an antenna device applied in a headset device.

2. The Related Art

In a prior art, a headset device generally includes a plastic cover, and an antenna device assembled to the plastic cover. Performance indexes of the antenna device are listed in a table shown inFIG. 5. When the antenna device works at a frequency of 2400 MHz, the maximum gain of the antenna device is 1.21 dBi, an efficiency of the antenna device is 28.18%, and an average gain of the antenna device is −5.50 dBi. When the antenna device works at a frequency of 2450 MHz, the maximum gain of the antenna device is 1.18 dBi, the efficiency of the antenna device is 28.99%, and the average gain of the antenna device is −5.38. When the antenna device works at a frequency of 2500 MHz, the maximum gain of the antenna device is 0.44 dBi, the efficiency of the antenna device is 24.92%, and the average gain of the antenna device is −6.03 dBi.

Currently, performance requirements of the headset device are requested higher and higher by a consumer. Not only does a function of the headset device need to be improved, but also a texture of the antenna device needs to be improved. In order to improve the texture of the headset device, a metal cover is applied in the headset device. So that, the headset device has a better appearance.

However, the metal cover has a larger area, when electromagnetic waves encounter the metal cover, electromagnetic waves will be reflected by the metal cover that will affect transmissions of the electromagnetic waves, if the metal cover is cut into pieces to reach a better radiating effect, the pieces of the metal cover need be integrally molded that will increase a manufacturing cost.

In view of the above-mentioned problems, an innovative antenna device is essential to be provided, the innovative antenna device is applied in a headset device with a metal cover and capable of effectively receiving and sending the electromagnetic signals.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an antenna device applied in a headset device. The antenna device includes a circuit board, an antenna body and a metal cover. The circuit board includes a flexible circuit board. The antenna body is mounted to and electrically connected with the flexible circuit board. The metal cover covers and adjacent to the antenna body and the circuit board. The antenna body is coupled with the metal cover to motivate each other to make the antenna body and the metal cover respectively become a first radiating element and a second radiating element.

As described above, the circuit board includes the flexible circuit board, and the metal cover covers and adjacent to the antenna body and the circuit board, the antenna body is coupled with the metal cover to motivate each other to make the antenna body and the metal cover respectively become the first radiating element and the second radiating element so as to reach a radiating purpose. As a result, a better radiating effect of the antenna device is realized without cutting the metal cover to decrease a manufacturing cost.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 1toFIG. 3, an antenna device100in accordance with the present invention is shown. The antenna device100is applied in a headset device200. The antenna device100in accordance with the present invention includes a circuit board10, an antenna body20and a metal cover30. The metal cover30is an outer cover portion of the headset device200. The headset device200is a Bluetooth headset.

The circuit board10includes a flexible circuit board11and a rigid circuit board12electrically connected with the flexible circuit board11. A front end of the flexible circuit board11is connected to a rear end of the rigid circuit board12. The flexible circuit board11is folded over the rigid circuit board12when the antenna device100is assembled completely. The circuit board10has an antenna circuit (not shown) and a ground circuit (not shown). The flexible circuit board11has the antenna circuit. The rigid circuit board12has the ground circuit.

The antenna body20is mounted to and electrically connected with the flexible circuit board11of the circuit board10. Specifically, the rigid circuit board12has a ground portion121. The antenna body20is a PIFA (Planar Inverted F-Antenna) type antenna or a loop type antenna. A material of the flexible circuit board11is copper, iron, gold, silver, stainless steel, a copper-nickel-zinc alloy, a copper nickel alloy, nickel silver copper, nickel, a piano wire, aluminum or any conductive metal.

The metal cover30covers and adjacent to the antenna body20and the circuit board10. The antenna body20is coupled with the metal cover30to motivate each other to make the antenna body20and the metal cover30respectively become a first radiating element and a second radiating element so as to reach a radiating purpose. A distance between the antenna body20and the metal cover30is within 4 mm to reach a better radiating effect.

The antenna body20is a monopole antenna. The antenna body20has a long strip-shaped first section21, a short strip-shaped second section22, a long strip-shaped third section23substantially parallel with the first section21, and a feeding section24. The first section21and the third section23extend substantially in a front-to-rear direction, the second section22is connected with rear ends of the first section21and the third section23. The feeding section24is connected with a front end of the first section21.

Preferably, the antenna body20is the PIFA type antenna, the antenna body20has the long strip-shaped first section21, the short strip-shaped second section22, the long strip-shaped third section23substantially parallel with the first section21, the feeding section24and a fourth section25. The first section21and the third section23extend substantially in the front-to-rear direction, the second section22is connected with the rear ends of the first section21and the third section23. The feeding section24is connected with the front end of the first section21. The fourth section25is extended perpendicularly and towards the third section23from a portion of the first section21adjacent to the front end of the first section21, and then perpendicularly bent frontward, the fourth section25is electrically connected with the ground portion121of the rigid circuit board12.

Preferably, the antenna body20is the loop type antenna, the antenna body20has the long strip-shaped first section21, the short strip-shaped second section22, the long strip-shaped third section23substantially parallel with the first section21, the feeding section24and a fifth section26. The first section21and the third section23extend substantially in the front-to-rear direction, the second section22is connected with the rear ends of the first section21and the third section23. The feeding section24is connected with the front end of the first section21. A front end of the third section23extends frontward to the rigid circuit board12to form the fifth section26. The fifth section26is electrically connected with the ground portion121of the rigid circuit board12.

The first radiating element is coupled with the second radiating element to receive and send the electromagnetic wave signals. Specifically, a radiating frequency band of the first radiating element and the second radiating element is ranged between 2400 MHz and 2500 MHz. The first radiating element and the second radiating element resonate at a frequency range covering 2400 MHz to 2500 MHz to receive and send the electromagnetic wave signals corresponding to a frequency band ranged between 2400 MHz and 2500 MHz. So that the antenna device100applied in the headset device200is capable of effectively receiving and sending the electromagnetic wave signals.

Referring toFIG. 1toFIG. 3, in use, the antenna device100is applied in the headset device200, a front end of the feeding section24is electrically connected with the antenna circuit of the flexible circuit board11. The ground portion121is electrically connected with the ground circuit of the rigid circuit board12. The metal cover30is integrally formed.

Referring toFIG. 1toFIG. 4, performance indexes of the antenna device100in accordance with the present invention are listed in a table shown inFIG. 4. When the antenna device100works at a frequency of 2400 MHz, the peak gain of the antenna device100is 1.64 dBi, an efficiency of the antenna device100is 29.66%, and an average gain of the antenna device100is −5.28 dBi. When the antenna device100works at a frequency of 2450 MHz, the peak gain of the antenna device100is 1.83 dBi, the efficiency of the antenna device100is 32.39%, and the average gain of the antenna device100is −4.9. When the antenna device100works at a frequency of 2500 MHz, the peak gain of the antenna device100is 0.74 dBi, the efficiency of the antenna device100is 26.20%, and the average gain of the antenna device100is −5.82 dBi. So the antenna device100has a better performance.

As described above, the circuit board10includes the flexible circuit board11, and the metal cover30covers and adjacent to the antenna body20and the circuit board10, the antenna body20is coupled with the metal cover30to motivate each other to make the antenna body20and the metal cover30respectively become the first radiating element and the second radiating element so as to reach the radiating purpose. As a result, the better radiating effect of the antenna device100is realized without cutting the metal cover30to decrease a manufacturing cost.