Coupling degree adjustment circuit, antenna device, and wireless communication device
A dielectric body includes a first radiating element on a first side and a second radiating element on a second side. The first radiating element and the second radiating element are linear conductors that each extend from a first end to a second end (an open end), and are parallel or substantially parallel to each other in a direction from the first end to the second end. The first end of the first radiating element is connected to a first port of a coupling degree adjustment circuit, and the first end of the second radiating element is connected to a second port of the coupling degree adjustment circuit. The first radiating element and the second radiating element are mainly coupled to each other in the coupling degree adjustment circuit.
1. A coupling degree adjustment circuit comprising:
a primary side circuit that includes a first coil element and is connected to a first radiating element; and
a secondary side circuit that includes a second coil element electromagnetically coupled to the first coil element, and is connected to a second radiating element.
2. The coupling degree adjustment circuit according to claim 1 , wherein the first coil element and the second coil element are integrally configured in a laminate including a plurality of dielectric layers or magnetic layers laminated on each other.
3. The coupling degree adjustment circuit according to claim 1 , wherein:
the first coil element includes a plurality of coil conductors that are interconnected in series and arranged adjacent to each other so as to define a closed magnetic circuit; and
the second coil element includes a plurality of coil conductors that are interconnected in series and arranged adjacent to each other so as to define a closed magnetic circuit.
4. The coupling degree adjustment circuit according to claim 1 , wherein the primary side circuit comprises a matching circuit connected between the first coil element and a connection port of the first radiating element or between the second coil element and a connection port of the second radiating element.
5. The coupling degree adjustment circuit according to claim 1 , wherein the primary side circuit comprises a matching circuit connected between a feeding port to which a feeding circuit is connected and the second radiating element.
6. The coupling degree adjustment circuit according to claim 1 , wherein the primary side circuit comprises a matching circuit connected between the first coil element and ground.
7. The coupling degree adjustment circuit according to claim 1 , wherein the secondary side circuit comprises a matching circuit connected between the second coil element and the ground.
8. The coupling degree adjustment circuit according to claim 1 , further comprising a matching circuit connected between the primary side circuit and the secondary side circuit.
9. The coupling degree adjustment circuit according to claim 1 , wherein:
the first radiating element is connected to a feeding circuit;
the second radiating element is connected to ground;
the first radiating element and the second radiating element are included in a multiple resonant antenna; and
a degree of coupling between the first radiating element and the second radiating element is adjustable.
10. An antenna device comprising:
a first radiating element;
a second radiating element; and
a coupling degree adjustment circuit connected between the first radiating element and the second radiating element, and a feeding circuit, the coupling degree adjustment circuit including:
a primary side circuit that includes a first coil element and is connected to the first radiating element; and
a secondary side circuit that includes a second coil element electromagnetically coupled to the first coil element, and is connected to the second radiating element.
11. The antenna device according to claim 10 , wherein a degree of coupling between the primary side circuit and the secondary side circuit is higher than a degree of coupling between the first radiating element and the second radiating element not through the coupling degree adjustment circuit.
12. The antenna device according to claim 10 , wherein the first coil element and the second coil element are integrally configured in a laminate including a plurality of dielectric layers or magnetic layers laminated on each other.
13. The antenna device according to claim 10 , wherein:
the first coil element includes a plurality of coil conductors that are interconnected in series and arranged adjacent to each other so as to define a closed magnetic circuit; and
the second coil element includes a plurality of coil conductors that are interconnected in series and arranged adjacent to each other so as to define a closed magnetic circuit.
14. The antenna device according to claim 10 , wherein the primary side circuit comprises a matching circuit connected between the first coil element and a connection port of the first radiating element or between the second coil element and a connection port of the second radiating element.
15. The antenna device according to claim 10 , wherein the primary side circuit comprises a matching circuit connected between a feeding port to which a feeding circuit is connected and the second radiating element.
16. The antenna device according to claim 10 , wherein the primary side circuit comprises a matching circuit connected between the first coil element and ground.
17. The antenna device according to claim 10 , wherein the secondary side circuit comprises a matching circuit connected between the second coil element and the ground.
18. The antenna device according to claim 10 , further comprising a matching circuit connected between the primary side circuit and the secondary side circuit.
19. A communication terminal apparatus comprising:
an antenna device including:
a first radiating element;
a second radiating element; and
a coupling degree adjustment circuit connected between the first radiating element and the second radiating element, and a feeding circuit, the coupling degree adjustment circuit including:
a primary side circuit that includes a first coil element and is connected to the first radiating element; and
a secondary side circuit that includes a second coil element electromagnetically coupled to the first coil element, and is connected to the second radiating element.
20. The communication terminal apparatus according to claim 19 , wherein a degree of coupling between the primary side circuit and the secondary side circuit is higher than a degree of coupling between the first radiating element and the second radiating element not through the coupling degree adjustment circuit.