Antenna element and portable information terminal

• US 6,670,924 B1
• Filed: 12/13/2001
• Issued: 12/30/2003
• Est. Priority Date: 04/13/2000
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Fukasawa, Toru, Shoji, Hideaki, Imanishi, Yasuhito, Ohmine, Hiroyuki
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US10/009,495
• Time in Patent Office: 747 Days
• Field of Search: 343/700.MS, 343/702, 343/725, 343/729, 343/829, 343/846, 343/872, 343/893, 343/895, 343/900
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/244 extendable from a housing along a given path
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system

Abstract

An antenna element includes a plate antenna which is substantially equivalent to a series resonant circuit, and a monopole antenna which is connected to the plate antenna and is substantially equivalent to a parallel resonant circuit.

Claims

1. An antenna element, comprising:

a first antenna part which is substantially equivalent to a series resonant circuit, and

a second antenna part which is brought in contact with and connected to said first antenna part and is substantially equivalent to a parallel resonant circuit,

said first and second antenna parts having reverse impedance characteristics connected so that reactances of said first and second antenna parts are substantially mutually canceled out in a predetermined frequency range.

2. The antenna element according to claim 1, wherein said first antenna part and said second antenna part are fitted in series to a feeding point.

3. The antenna element according to claim 1, wherein said first antenna part and said second antenna part are fitted in parallel to a feeding point.

4. The antenna element according to claim 1, wherein the first antenna part comprises a plate antenna, and said second antenna part comprises a linear antenna.

5. The antenna element according to claim 4, wherein said linear antenna comprises at least one selected from the group consisting of a monopole antenna and a helical antenna.

6. The antenna element according to claim 1, which further comprises a substrate whose surface has an electrical conductivity,

said first antenna part being set up, through a dielectric, over the surface of said substrate, and

said second antenna part being set up to extend from said substrate.

7. The antenna element according to claim 1, which further comprises a substrate whose surface has an electrical conductivity,

said first antenna part and second antenna part being set up, through a dielectric, over the surface of said substrate.

8. The antenna element according to claim 7, wherein said second antenna part comprises at least one selected from the group consisting of a monopole antenna, a helical antenna, a meander line antenna, and a zigzag antenna.

9. A portable information terminal, comprising an antenna element comprising a first antenna part which is substantially equivalent to a series resonant circuit, and a second antenna part which is connected to said first antenna part and is substantially equivalent to a parallel resonant circuit,

said first and second antenna parts having reverse impedance characteristics connected so that reactances of said first and second antenna parts are substantially mutually canceled out in a predetermined frequency range.