Miniature antenna and electromagnetic field sensing apparatus

• US 20040131301A1
• Filed: 12/17/2003
• Published: 07/08/2004
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Huang, Mao-Sheng, Ferng, Jen-Ming, Liang, Wen-Lie, Shay, Wen-Tron, Tseng, Wen-Jen
• Granted Patent: US 7,088,879 B2
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: G01R 29/0885 using optical probes, e.g. electro-optical, luminescent, glow discharge, or optical interferometers
• CPC Class Codes: G02B 2006/12142 Modulator
• CPC Class Codes: G02F 1/225 in an optical waveguide structure
• CPC Class Codes: H01Q 3/2676 Optically controlled phased array
• 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

Abstract

An electromagnetic field sensing apparatus includes an optical modulator, a miniature antenna for sensing the electromagnetic field, a light source, a first optical fiber, an optical detector and a second fiber. The optical modulator can vary the amplitude of a light beam propagating therethrough in response to an electric field intensity. The miniature antenna for sensing the electromagnetic field can sense both the electric field intensity and the magnetic field intensity of an electromagnetic field and apply an electric voltage to the optical modulator in response to the sensed electromagnetic field intensity. The light source is used to generate a light beam, the first optical fiber is used for transmitting the light beam to the modulator, and the second fiber is used for transmitting the light beam from the modulator to the optical detector.

Claims

1. A miniature antenna, comprising:

a first line;

a first optical switch positioned at one end of the first line;

a second optical switch positioned at the other end of the first line;

a second line connected to the first optical switch;

a third line connected to the second optical switch; and

wherein the first optical switch and the second optical switch are used for sensing a magnetic field when being turned on and used for sensing an electric field when being turned off.

2. The miniature antenna of claim 1, being formed on a mica substrate.

3. The miniature antenna of claim 1, wherein switching signals are transmitted between the first optical switch and the second optical switch by an optical fiber.

4. The miniature antenna of claim 1, wherein the second line and the third line are formed substantially in straight.

5. The miniature antenna of claim 1, wherein the first line, the second line and the third line are formed substantially as a loop.

6. The miniature antenna of claim 5, wherein the loop is rectangular or circular.

7. An electromagnetic field sensing apparatus, comprising:

a light source for generating a light beam;

an optical modulator for changing a phase of the light beam propagating therethrough in response to an electric field;

an miniature antenna for transforming the sensed electromagnetic field into an electric field and then applying to the optical modulator;

a first optical fiber for transmitting the light beam to the optical modulator;

a second optical fiber connected to the optical modulator; and

an optical detector for transforming the light beam transmitted from the second optical fiber into an electrical signal.

8. The electromagnetic field sensing apparatus of claim 7, wherein the miniature antenna comprises:

a first line;

a first optical switch positioned at one end of the first line;

a second optical switch positioned at the other end of the first line;

a second line connected to the first optical switch;

a third line connected to the second optical switch; and

wherein the first optical switch and the second optical switch are used for sensing a magnetic field when being turned on and used for sensing an electric field when being turned off.

9. The electromagnetic field sensing apparatus of claim 8, wherein the miniature antenna is formed on a mica substrate.

10. The electromagnetic field sensing apparatus of claim 8, wherein the second line and the third line are formed substantially in straight.

11. The electromagnetic field sensing apparatus of claim 8, wherein the first line, the second line and the third line are formed substantially as a loop.

12. The electromagnetic field sensing apparatus of claim 11, wherein the loop is rectangular or circular.

13. The electromagnetic field sensing apparatus of claim 8, wherein the optical modulator feedbacks an average level of the electrical signal to the light source for controlling the wavelength of the light beam.