Antenna device

• US 6,473,049 B2
• Filed: 11/30/2001
• Issued: 10/29/2002
• Est. Priority Date: 12/07/2000
• Status: Expired due to Fees

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Ikawa, Koji, Watanabe, Fuminori, Takeuchi, Shoichi
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US09/997,004
• Publication Number:
  US 20020101390A1
• Time in Patent Office: 333 Days
• Field of Search: 343/753, 343/755, 343/781.R, 343/781.P, 343/781.CA, 343/910, 343/911.R, 343/911.L
• US Class Current: 343/753
• CPC Class Codes: H01Q 1/1271 for mounting on windscreens
• CPC Class Codes: H01Q 19/062 for focusing
• CPC Class Codes: H01Q 19/065 Zone plate type antennas
• CPC Class Codes: H01Q 19/19 comprising one main concave reflecting surface associated with an auxiliary reflecting surface

Abstract

An antenna device of simple structure and high performance which is capable of lessening a reduction of a converging efficiency of radio wave due to a window glass sheet or the like to which the antenna device is fitted, and capable of obtaining a high converging efficiency to a received radio wave. The antenna device comprises a fitted member (5) having transparency, a converging member (1) for converging a radio wave, a space between the fitted member (5) and the converging member (1), and a receiving portion for receiving the radio wave converged by the converging member (1) or a transmitting portion for radiating a radio wave to the converging member (1) wherein in a case that a receive power value is changed so as to take alternately a bottom value and a peak value depending on a change of the thickness of the space, the thickness of the space is adjusted so that the received power value does not take a value in the vicinity of bottom values.

Claims

1. An antenna device comprising:

a fitted member having transparency;

a converging member for converging a radio wave;

a space between the fitted member and the converging member; and

at least one of a receiving portion for receiving the radio wave converged by the converging member and a transmitting portion for radiating a radio wave to the converging member;

wherein the fitted member is a window glass sheet fitted to a building; and

wherein the converging member has a face, and the space is a space constituted by inclining relatively the converging member with respect to the window glass sheet to an angle other than parallel.

2. The antenna device according to claim 1, wherein in a case that a received power value is changed so as to take alternately a bottom value and a peak value depending on a change of the thickness of the space in the relation between the thickness of the space and the received power value, the thickness of the space is adjusted so that the received power value does not take a value in the vicinity of bottom values.

3. The antenna device according to claim 2, wherein in a case that the thickness of the fitted member satisfies the following formula (1) with respect to the wavelength of the radio wave and the incident angle of the radio wave, the space has an adjusted thickness:

$\begin{array}{cc}\left(\frac{2<br><br>n+1}{4}-\frac{1}{5}\right)·<br><br>{\mathrm{\lambda <br><br>}}_d\le <br><br>L\le <br><br>\left(\frac{2<br><br>n+1}{4}+\frac{1}{5}\right)·<br><br>{\mathrm{\lambda <br><br>}}_d& \left(1\right)\end{array}$

where n is an integer of 0 or more;

λ

_d is a wavelength of the radio wave passing through the fitted member;

${\mathrm{\lambda <br><br>}}_d=\frac{\mathrm{\lambda <br><br>}}{\sqrt{{\mathrm{\varepsilon <br><br>}}_r-{\sin }^2<br><br>\mathrm{\theta <br><br>}}}$

(λ

is a wavelength of the radio wave in vacuum, ε

_r is the relative permittivity of the fitted member, and θ

is an incident angle of the radio wave), and L is a thickness of the fitted member.

4. The antenna device according to claim 1, wherein in a case that a received power value is changed so as to take alternately a bottom value and a peak value depending on a change of the thickness of the space in the relation between the thickness of the space and the received power value, the thickness of the space is adjusted so that the received power value takes a value which approaches a peak value at least ⅔

in the difference in terms of a dB value between the peak value and the bottom value having a smaller value in two bottom values which are at both sides of the peak value.

5. The antenna device according to claim 1, wherein the sum of the maximum distance between the window glass sheet and the converging member, and the thickness of the converging member is 200 mm or less.

6. The antenna device according to claim 1, further comprising a mechanical adjustment element configured to incline the converging member.

7. An antenna device comprising:

a fitted member having transparency;

a converging member for converging a radio wave;

a space between the fitted member and the converging member; and

at least one of a receiving portion for receiving the radio wave converged by the converging member and a transmitting portion for radiating a radio wave to the converging member;

wherein in a case that a received power value is changed so as to take alternately a bottom value and a peak value depending on a change of the thickness of the space in the relation between the thickness of the space and the received powder value, the thickness of the space is adjusted so that the received powder value does not take a value in the vicinity of bottom values.

8. The antenna device according to claim 7, wherein in a case that the thickness of the fitted member satisfies the following formula (1) with respect to the wavelength of the radio wave and the incident angle of the radio wave, the space has an adjusted thickness:

$\begin{array}{cc}\left(\frac{2<br><br>n+1}{4}-\frac{1}{5}\right)·<br><br>{\mathrm{\lambda <br><br>}}_d\le <br><br>L\le <br><br>\left(\frac{2<br><br>n+1}{4}+\frac{1}{5}\right)·<br><br>{\mathrm{\lambda <br><br>}}_d& \left(1\right)\end{array}$

where n is an integer of 0 or more;

λ

_d is a wavelength of the radio wave passing through the fitted member;

${\mathrm{\lambda <br><br>}}_d=\frac{\mathrm{\lambda <br><br>}}{\sqrt{{\mathrm{\varepsilon <br><br>}}_r-{\sin }^2<br><br>\mathrm{\theta <br><br>}}}$

(λ

is a wavelength of the radio wave in vacuum, ε

_r is the relative permittivity of the fitted member, and θ

is an incident angle of the radio wave), and L is a thickness of the fitted member.

9. The antenna device according to claim 7, wherein the sum of the distance between the fitted member and the converging member, and the thickness of the converging member is 200 mm or less.

10. The antenna device according to claim 7, further comprising a position-adjustable slider configured to adjust the position of said space.

11. The antenna device according to claim 7, wherein the space is a closed space between the fitted member and the converging member, said closed space being filled with an inert gas.

12. An antenna device comprising:

a fitted member having transparency;

a converging member for converging a radio wave;

a space between the fitted member and the converging member; and

at least one of a receiving portion for receiving the radio wave converged by the converging member and a transmitting portion for radiating a radio wave to the converging member;

wherein in a case that a received powder value is changed so as to take alternately a bottom value and a peak value depending on a change of the thickness of the space in the relation between the thickness of the space and the received power value, the thickness of the space is adjusted so that the received power value takes a value which approaches a peak value at least ⅔

of a difference in terms of a dB value between the peak value and the bottom value having a smaller value in two bottom values which are at both sides of the peak value.

13. The antenna device according to claim 12, further comprising a position-adjustable slider configured to adjust the position of said space.

14. The antenna device according to claim 12, wherein the sum of the distance between the fitted member and the converging member, and the thickness of the converging member is 200 mm or less.

15. An antenna device which comprises a flat fitted member having transparency, an antenna member for performing at least one of transmitting a radio wave and receiving a radio wave and a space between the fitted member and the antenna member wherein in a case that a received power value is changed so as to take alternately a bottom value and a peak value depending on a change of the thickness of the space in the relation between the thickness of the space and the received power value in the antenna member, the thickness of the space is adjusted and determined so that the received power value does not take a value in the vicinity of bottom values.

16. The antenna device according to claim 15, wherein the thickness of the space is determined so that the received power value takes a value which approaches a peak value at least ⅔

in the difference in terms of a dB value between the peak value and the bottom value having a smaller value between two bottom values which are at both sides of the peak value.

17. The antenna device according to claim 15, wherein in a case that the thickness of the fitted member satisfies the following formula (2) with respect to the wavelength of the radio wave and the incident angle of the radio wave, the space has an adjusted thickness under determination:

$\begin{array}{cc}\left(\frac{2<br><br>n+1}{4}-\frac{1}{5}\right)·<br><br>{\mathrm{\lambda <br><br>}}_d\le <br><br>L\le <br><br>\left(\frac{2<br><br>n+1}{4}+\frac{1}{5}\right)·<br><br>{\mathrm{\lambda <br><br>}}_d& \left(2\right)\end{array}$

where n is an integer of 0 or more;

λ

_d is a wavelength of the radio wave passing through the fitted member;

${\mathrm{\lambda <br><br>}}_d=\frac{\mathrm{\lambda <br><br>}}{\sqrt{{\mathrm{\varepsilon <br><br>}}_r-{\sin }^2<br><br>\mathrm{\theta <br><br>}}}$

(λ

is a wavelength of the radio wave in vacuum, ε

_r is the relative permittivity of the fitted member, and θ

is an incident angle of the radio wave), and L is a thickness of the fitted member.

18. The antenna device according to claim 15, further comprising a position-adjustable slider configured to adjust the position of said space.