Mobile electronic device

• US 8,816,920 B2
• Filed: 04/26/2011
• Issued: 08/26/2014
• Est. Priority Date: 04/26/2010
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Abe, Yasuhiro, Sakai, Hiroshi
• Primary Examiner(s): TRAIL, ALLYSON NEEL
• Application Number:
  US13/094,405
• Publication Number:
  US 20110260940A1
• Time in Patent Office: 1,218 Days
• Field of Search: 343/45, 343/745, 455/571, 455/550.1, 455/77, 455/73, 455/78
• US Class Current: 343/745
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 5/50 Feeding or matching arrangements for broad-band or multi-band operation
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna

Abstract

A mobile electronic device comprises an RFID antenna section that sends and receives signals on a first useful frequency band, a main antenna section that sends and receives signals on a second useful frequency band, which is a higher frequency band than the first useful frequency band, an adjustment section that adjusts a resonance frequency of the RFID antenna section, and a control section that identifies a reactance value of the RFID antenna section based on the receiving sensitivity with respect to signals on the first useful frequency band and adjusts the resonance frequency of the RFID antenna section based on the identified reactance value by an adjustment section such that a high-order resonance frequency of the RFID antenna section is spaced apart from the second useful frequency band.

Claims

1. A mobile electronic device comprising:

a housing;

a first antenna section that is arranged in the housing, and sends and receives signals on a first useful frequency band;

a second antenna section that is arranged in the housing, and sends and receives signals on a second useful frequency band that is a higher frequency band than the first useful frequency band;

an adjustment section that adjusts a resonance frequency of the first antenna section; and

a control section that identifies a reactance value of the first antenna section based on a receiving sensitivity with respect to the signals on the first useful frequency band, and adjusts, by the adjustment section, the resonance frequency of the first antenna section based on the identified reactance value such that a high-order resonance frequency of the first antenna section is spaced apart from the second useful frequency band in cases in which the receiving sensitivity falls below a predetermined value when the second antenna section receives a signal on the second useful frequency band.

2. The mobile electronic device according to claim 1, comprising:

a separating section that separates the first antenna section into a first loop section that turns a first number of rotations that is less than a predetermined number of rotations and a second loop section that turns a second number of rotations, which is a number of rotations derived from the subtraction of the first number of rotations from the predetermined number of rotations;

a signal generation section that is connected to either the first loop section or the second loop section and generates a signal at a reference frequency from a loop section of a relevant connected side;

a detecting section that is connected to the other one of the first loop section and the second loop section and detects electrical characteristics of the relevant connected loop section;

wherein, the adjustment section is connected to the other one of the first loop section and the second loop section and adjusts the resonance frequency of the relevant connected loop section, the control section separates the first antenna section into the first loop section and the second loop section by the separating section, generates a signal at a reference frequency of one of the first loop section and the second loop section by the signal generation section and detects an electrical characteristics of the other one of the first loop section and the second loop section by the detecting section, and adjusts a resonance frequency of the other one of the first loop section and the second loop section by the adjustment section in accordance with detection result of the detecting section.

3. The mobile electronic device according to claim 2, further comprising an operation detecting section that detects operations,

wherein, the control section separates the first antenna section into the first loop section and the second loop section when a prescribed operation is detected, generates a signal of reference frequency from one of the first loop section and the second loop section by the signal generation section, and detects electrical characteristics of the other one of the first loop section and the second loop section by the detecting section, and adjusts the resonance frequency of the other one of the first loop section and second loop section by the adjustment section in accordance with the detection result of the detecting section.

4. The mobile electronic device according to claim 2, wherein

the control section periodically separates the first antenna section into the first loop section and the second loop section, generates a signal at a reference frequency from one of the first loop section and the second loop section by the signal generation section, detects electrical characteristics of the other one of the first loop section and the second loop section by the detecting section, and adjusts the resonance frequency of the other one of the first loop section and second loop section by the adjustment section in accordance with the detection result of the detecting section.

5. The mobile electronic device according to claim 2, wherein

the signal generation section, the detecting section and the adjustment section are connectable to both the first loop section and the second loop section,

the control section separates the first antenna section into the first loop section and the second loop section by the separating section, generates a signal at a reference frequency from both the first loop section and the second loop section by the signal generation section, and detects both electrical characteristics of the first loop section and the second loop section by the detecting section, and adjusts the resonance frequencies of both the first loop section and second loop section by the adjustment section in accordance with the detection results of the detecting section.

6. The mobile electronic device according to claim 5, wherein

the control section releases the separation by the separating section, and adjusts the resonance frequency of the first antenna section by the adjustment section in accordance with electrical characteristics of both the first loop section and the second loop section detected by the detecting section.

7. The mobile electronic device according to claim 2, wherein

the separating section separates into the first loop section and the second loop section such that the first number of rotations and the second number of rotations are equal.

8. The mobile electronic device according to claim 1, further comprising a variable type capacitor connected to the first antenna section,

wherein the control section adjusts the resonance frequency of the first antenna section by adjusting the capacitance of the capacitor by the adjustment section such that a high-order resonance frequency of the first antenna section is spaced apart from the second useful frequency band.