Antenna and mobile terminal
An antenna for a mobile terminal includes a substrate, a dipole placed on the substrate, a loop placed on the substrate, and a matching circuit on the substrate. The matching circuit comprises at least one of a variable capacitor or a variable inductor. The radiation center of the loop substantially coincides with the radiation center of the dipole.
1. An antenna comprising:
a substrate;
a dipole placed on one side of the substrate;
a loop placed on another side of the substrate substantially opposite to the side of the substrate on which the dipole is formed, wherein a radiation center of the loop substantially coincides with a radiation center of the dipole; and
a matching circuit on the substrate,
wherein the matching circuit comprises at least one of a variable capacitor or a variable inductor, and
wherein the matching circuit changes phases of electric currents to provide a directed radiation pattern by the antenna if a received power is poor, and the matching circuit changes the phases of electric currents to provide an all-directed radiation pattern by the antenna if the received power is good.
2. The antenna of claim 1 , wherein the dipole is formed as a strip structure.
3. The antenna of claim 1 , wherein a phase difference of electric currents supplied for the dipole and the loop is 90°.
4. The antenna of claim 1 , wherein a phase difference of electric currents supplied for two ports of the loop is 180°.
5. The antenna of claim 1 , wherein the matching circuit is configured to provide substantially equal power radiated by both the dipole and the loop.
6. The antenna of claim 5 , wherein the matching circuit changes a phase difference of electric currents supplied for the dipole and the loop.
7. The antenna of claim 5 , wherein the matching circuit is an LC circuit.
8. The antenna of claim 5 , wherein the dipole, the loop and the matching circuit are designed as a microstrip integrated circuit.
9. The antenna of claim 1 , further comprising a PCB ground.
10. The antenna of claim 1 , wherein the loop comprises a lumped capacitor at a middle position of the loop.
11. The antenna of claim 10 , further comprising:
a plurality of connecting ports connecting the dipole and the loop with the matching circuit,
wherein the loop is rectangular and the lumped capacitor is located opposite the connecting ports.
12. A mobile terminal comprising an antenna, the antenna comprising:
a substrate;
a dipole placed on the substrate;
a loop placed on the substrate, wherein a radiation center of the loop substantially coincides with a radiation center of the dipole; and
a matching circuit on the substrate,
wherein the matching circuit comprises at least a variable capacitor or a variable inductor,
wherein the matching circuit changes phases of electric currents to provide a directed radiation pattern by the antenna if a received power is poor, and the matching circuit changes the phases of electric currents to provide an all-directed radiation pattern by the antenna if the received power is good.
13. The mobile terminal of claim 12 , wherein the matching circuit is configured to provide substantially equal power radiated by both the dipole and the loop.
14. The mobile terminal of claim 13 , wherein the matching circuit changes a phase difference of electric currents supplied for the dipole and the loop.
15. The mobile terminal of claim 13 , wherein the matching circuit is an LC circuit.
16. The mobile terminal of claim 12 , wherein the antenna further comprises a PCB ground.