Sensor and information acquisition apparatus using sensor

Patent metadata

Field	Value
Publication number	US-2016169746-A1
Application number	US-201514948108-A
Country	US
Kind code	A1
Filing date	Nov 20, 2015
Priority date	Nov 28, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

A sensor to detect information on a subject by using an electromagnetic wave includes a transmitting unit having a generating element and a first antenna, a polarization converting unit, and a receiving unit having a second antenna and a detecting device. The generating element generates an electromagnetic wave, and the first antenna emits the electromagnetic wave generated by the generating element as first polarization. The polarization converting unit converts the first polarization into second polarization by changing a polarization direction of the first polarization. The second antenna receives the second polarization, and the detecting device detects the electromagnetic wave received by the second antenna. The transmitting unit and the receiving unit are disposed on the same substrate.

First claim

What is claimed is:

1 . A sensor to detect information on a subject by using an electromagnetic wave, the sensor comprising:
a transmitting unit having a generating element configured to generate an electromagnetic wave, and a first antenna configured to emit the electromagnetic wave generated by the generating element as first polarization; a polarization converting unit configured to convert the first polarization into second polarization by changing a polarization direction of the first polarization; and a receiving unit having a second antenna configured to receive the second polarization, and a detecting device configured to detect the electromagnetic wave received by the second antenna, wherein the transmitting unit and the receiving unit are disposed on the same substrate.

2 . The sensor according to claim 1 , wherein the first antenna is selectively combined with the first polarization, and the second antenna is selectively combined with the second polarization.

3 . The sensor according to claim 1 , wherein the polarization converting unit includes a first converting unit configured to convert terahertz wave generated by the generating element into third polarization by changing a polarization direction of the terahertz wave, and a second converting unit configured to convert the third polarization into the second polarization by changing a polarization direction of the third polarization.

4 . The sensor according to claim 3 , wherein the first converting unit and the second converting unit are integrated with each other.

5 . The sensor according to claim 3 ,
wherein the first converting unit is disposed on a propagation path between transmission of the first polarization from the transmitting unit and arrival at the subject, and wherein the second converting unit is disposed on a propagation path after the third polarization reflects on the subject until the third polarization enters the receiving unit.

6 . The sensor according to claim 1 , wherein the polarization converting unit is disposed on a propagation path between transmission of the first polarization from the transmitting unit and arrival at the subject, or on a propagation path between reflection of the first polarization on the subject and the first polarization entering the receiving unit.

7 . The sensor according to claim 1 , wherein the first polarization and the second polarization are each linear polarization, and the polarization direction of the first polarization and the polarization direction of the second polarization cross each other.

8 . The sensor according to claim 7 , wherein the polarization direction of the first polarization and the polarization direction of the second polarization perpendicularly cross each other.

9 . The sensor according to claim 1 , wherein the polarization converting unit includes a quarter wavelength plate that is disposed in a manner such that a crystal axis thereof rotates with respect to an optical axis of the first polarization and an optical axis of the second polarization.

10 . The sensor according to claim 9 , wherein the quarter wavelength plate is disposed with an angle between a fast axis/a slow axis and the polarization direction of the first polarization/the polarization direction of the second polarization is 45°.

11 . The sensor according to claim 1 , further comprising a plurality of receiving units,
wherein a distance between adjoining receiving units or a distance between adjoining transmitting unit and receiving unit is equal to or shorter than twice the wavelength of each of the first polarization and the second polarization.

12 . The sensor according to claim 1 , wherein the polarization converting unit is integrated on the transmitting unit and the receiving unit.

13 . The sensor according to claim 1 ,
wherein the transmitting unit includes a first conductor, a second conductor, and a first dielectric material and the generating element is disposed between the first conductor and the second conductor, wherein the receiving unit includes a third conductor, a fourth conductor, and a second dielectric material and the detecting device is disposed between the third conductor and the fourth conductor, wherein the generating element is disposed at position shifted from a centroid of the first conductor, wherein the detecting device is disposed at a position shifted from a centroid of the third conductor, and wherein a line connecting the generating element and the centroid of the first conductor and a line connecting the detecting device and the centroid of the third conductor cross each other.

14 . The sensor according to claim 1 , further comprising a conductor,
wherein each of the first and second antennae is a slot antenna including an opening provided in the conductor, and wherein a longitudinal direction of the opening of the first antenna and a longitudinal direction of the opening of the second antenna cross each other.

15 . The sensor according to claim 1 , wherein the transmitting unit is disposed on the substrate, and the receiving unit is disposed on the transmitting unit.

16 . The sensor according to claim 1 , wherein the receiving unit is disposed on the substrate, and the transmitting unit is disposed on the receiving unit.

17 . The sensor according to claim 1 , wherein the generating element includes a negative resistance device.

18 . The sensor according to claim 1 , wherein the detecting device includes a rectifier.

19 . The sensor according to claim 18 , wherein the rectifier is a Schottky barrier diode.

20 . An information acquisition apparatus comprising:
a sensor to detect information on a subject by using an electromagnetic wave, wherein the sensor includes: a transmitting unit having a generating element configured to generate an electromagnetic wave, and a first antenna configured to emit the electromagnetic wave generated by the generating element as first polarization, a polarization converting unit configured to convert the first polarization into second polarization by changing a polarization direction of the first polarization, and a receiving unit having a second antenna configured to receive the second polarization, and a detecting device configured to detect the electromagnetic wave received by the second antenna, wherein the transmitting unit and the receiving unit are disposed on the same substrate; and an information acquisition unit configured to acquire information on the subject using a detection result of the detecting device.

Assignees

• Canon Kk

Inventors

• Koyama Yasushi
• Ouchi Toshihiko

Classifications

• A61B5/0507

  using microwaves or terahertz waves · CPC title

• G01N21/21

  Polarisation-affecting properties (G01N21/19 takes precedence) · CPC title

• A61B5/6828

  Leg · CPC title

• G01J5/0837

  Microantennas, e.g. bow-tie · CPC title

• G01N21/3581 Primary

  using far infrared light; using Terahertz radiation · CPC title