Antenna system and communication device containing the same
The present disclosure relates to an antenna system and a communication device. The antenna system includes a rear housing, a metal middle frame including two side frame portions and a bottom frame portion, a mainboard and a first tuning switch. The bottom frame portion defines a first slit and a second slit and includes a first, second and third positions, a third slit communicated with the first and second slits is defined between the rear housing and the bottom frame portion along an extending direction of the side frame portion. The mainboard includes a feeding point, a first ground point and a second ground point, the feeding point connected with the first position, the first ground point connected with the second position, the second ground point connected with the third position by the first tuning switch, thereby forming a first antenna, a second antenna and a third antenna.
1. An antenna system, comprising:
a rear housing,
a metal middle frame circumferentially surrounding and connected with the rear housing, the metal middle frame comprising two side frame portions opposite to each other and a bottom frame portion connecting the two side frame portions, the bottom frame portion comprising a first position, a second position and a third position,
a mainboard provided with a feeding point, a first ground point and a second ground point, and
a first tuning switch, wherein
the bottom frame portion defines a first slit and a second slit, a third slit is defined between the rear housing and the bottom frame portion along an extending direction of the two side frame portions, and one end of the third slit is communicated with the first slit, and the other end of the third slit is communicated with the second slit; and
the feeding point is connected with the first position; the first ground point is connected with the second position; the second ground point is connected with the third position by the first tuning switch; and the first position, the second position and the third position are located between the first slit and the second slit, and the second position is located between the first position and the third position, thereby forming a first antenna, a second antenna, and a third antenna;
the antenna system further comprising an antenna unit and a second tuning switch, wherein the antenna unit is connected with the bottom frame portion by the second tuning switch, and the second tuning switch is placed on a side of the second slit away from the first slit, for forming a fourth antenna.
2. The antenna system as described in claim 1 , wherein the first tuning switch has a connected state, a disconnected state, an inductor access state and a capacitor access state;
when the first tuning switch is in the connected state, the second ground point is connected with the bottom frame portion;
when the first tuning switch is in the disconnected state, the second ground point is disconnected from the bottom frame portion;
when the first tuning switch is in the inductor access state, the second ground point is connected with the metal middle frame by an inductor; and
when the first tuning switch is in the capacitor access state, the second ground point is connected with the bottom frame portion by a capacitor.
3. The antenna system as described in claim 2 , wherein the capacitor is an adjustable capacitor.
4. The antenna system as described in claim 1 , wherein the antenna unit comprises a metal wiring, the metal wiring is placed opposite to and spaced from the bottom frame portion; and one end of the metal wiring is connected with the bottom frame portion by the second tuning switch, and the other end of the metal wiring is a free end.
5. The antenna system as described in claim 4 , wherein the metal wiring is placed opposite to sections of the bottom frame portion on two sides of the second slit and opposite to the second slit.
6. The antenna system as described in claim 1 , wherein the second tuning switch has a connected state and a disconnected state;
when the second tuning switch is in the connected state, the antenna unit is connected with the bottom frame portion to make the antenna unit be coupled to the bottom frame portion, thereby forming a fourth antenna; and
when the second tuning switch is in the disconnected state, the antenna unit is disconnected from the bottom frame portion.
7. The antenna system as described in claim 6 , wherein a main radiator of the fourth antenna comprises the antenna unit and a part of the bottom frame portion located on a side of the first position away from the second position.
8. The antenna system as described in claim 1 , wherein a main radiator of the first antenna and the second antenna comprises a part of the bottom frame portion on a side of the first position away from the second slit; and
a main radiator of the third antenna comprises a part of the bottom frame portion located on a side of the first position away from the second position.
9. A communication device, comprising the antenna system as described in claim 1 .