Tunable parasitic resonators

• US 20050043055A1
• Filed: 10/14/2003
• Published: 02/24/2005
• Est. Priority Date: 08/07/2003
• Status: Active Grant

• Current Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Inventors: Vance, Scott L.
• Granted Patent: US 7,162,264 B2
• Time in Patent Office: Days
• US Class Current: 455/550.100
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• CPC Class Codes: H01Q 19/005 Patch antenna using one or more coplanar parasitic elements

Abstract

A mobile terminal can include a printed circuit board with a reference voltage conductor, an antenna coupled to the first side of the printed circuit board, and a parasitic resonator coupled to the second side of the printed circuit board. More particularly, the parasitic resonator can be connected to the printed circuit board by first and second couplings, which provide first and second impedances, respectively, between the parasitic resonator and the reference voltage conductor. The impedances can be of different values, and can be provided by discrete impedance components. The resonant frequency of the parasitic resonator can be adjusted by altering the impedances of the first and second couplings.

Claims

1. A mobile terminal comprising:

a printed circuit board having first and second sides and having a reference voltage conductor therein;

an antenna coupled to the first side of the printed circuit board; and

a parasitic resonator having first and second couplings to the second side of the printed circuit board so that the printed circuit board is between the antenna and the parasitic resonator, wherein the first coupling to the printed circuit board provides a first impedance between the parasitic resonator and the reference voltage conductor, and wherein the second coupling to the printed circuit board provides a second impedance between the resonator and the reference voltage conductor wherein the first and second impedances are different.

2. A mobile terminal according to claim 1 wherein the first coupling provides an electrical short between the parasitic resonator and the reference voltage conductor and wherein the second coupling provides at least one of a capacitance and/or an inductance between the reference voltage conductor and the parasitic resonator.

3. A mobile terminal according to claim 1 wherein the second coupling provides a capacitance between the reference voltage conductor and the parasitic resonator that is greater than a capacitance provided by the first coupling between the reference voltage conductor and the parasitic resonator.

4. A mobile terminal according to claim 1 wherein the second coupling provides an inductance between the reference voltage conductor and the parasitic resonator that is greater than an inductance provided by the first coupling between the reference voltage conductor and the parasitic resonator.

5. A mobile terminal according to claim 1 wherein at least one of the first and second couplings comprises a discrete impedance element between the parasitic resonator and the reference voltage conductor.

6. A mobile terminal according to claim 5 wherein the discrete impedance element comprises at least one of a discrete capacitor, a discrete inductor, and/or a discrete resistor.

7. A mobile terminal according to claim 6 wherein the discrete impedance element is soldered on the printed circuit board.

8. a mobile terminal according to claim 5 wherein each of the first and second couplings comprises a discrete impedance element between the parasitic resonator and the reference voltage conductor.

9. A mobile terminal comprising:

a printed circuit board having first and second sides and having a reference voltage conductor therein;

an antenna coupled to the first side of the printed circuit board; and

a parasitic resonator having first and second couplings to the second side of the printed circuit board so that the printed circuit board is between the antenna and the parasitic resonator, wherein at least one of the first and second couplings to the printed circuit board comprises a discrete impedance element between the parasitic resonator and the reference voltage conductor.

10. A mobile terminal according to claim 9 wherein the discrete impedance element comprises at least one of a discrete capacitor, a discrete inductor, and/or a discrete resistor.

11. A mobile terminal according to claim 10 wherein the discrete impedance element is soldered on the printed circuit board.

12. A mobile terminal according to claim 9 wherein each of the first and second couplings comprises a discrete impedance element between the parasitic resonator and the reference voltage conductor.

13. A method according to claim 9 wherein the first coupling to the printed circuit board provides a first impedance between the parasitic resonator and the reference voltage conductor, and wherein the second coupling to the printed circuit board provides a second impedance between the resonator and the reference voltage conductor wherein the first and second impedances are different.

14. A mobile terminal according to claim 13 wherein the first coupling provides an electrical short between the parasitic resonator and the reference voltage conductor and wherein the second coupling provides at least one of a capacitance and/or an inductance between the reference voltage conductor and the parasitic resonator.

15. A mobile terminal according to claim 13 wherein the second coupling provides a capacitance between the reference voltage conductor and the parasitic resonator that is greater than a capacitance provided by the first coupling between the reference voltage conductor and the parasitic resonator.

16. A mobile terminal according to claim 13 wherein the second coupling provides an inductance between the reference voltage conductor and the parasitic resonator that is greater than an inductance provided by the first coupling between the reference voltage conductor and the parasitic resonator.