Communications: radio wave antennas – Antennas – With spaced or external radio wave refractor
Reexamination Certificate
2002-10-16
2004-04-13
Nguyen, Hoang V. (Department: 2821)
Communications: radio wave antennas
Antennas
With spaced or external radio wave refractor
C343S7000MS, C343S770000, C343S771000, C343S909000, C343S757000
Reexamination Certificate
active
06720931
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a beam scanning plane antenna used for performing transmission/reception in micro wave band or millimetric wave band.
BACKGROUND ART
The beam scanning antenna, which irradiates with electric waves in all directions of a specific range by changing the angle of the irradiation direction with time passage, often uses Rotman lens as a lens for converting signals from its system to scanning electric waves. As shown in
FIG. 1A
, this Rotman lens has a micro strip structure comprising a power feeding substrate
6
on which connecting lines
10
for connecting with the system, and power feeding lines
4
are formed; and a grounding conductor
3
attached on the rear face thereof. The power feeding lines
4
are connected to irradiating elements
5
through coaxial lines
15
connected to connectors.
To reduce the quantity of components or the size thereof, as shown in
FIG. 1B
, it is permissible to have a construction which connects the power feeding lines
4
with the irradiating elements
5
electromagnetically.
In case of the antenna shown in
FIG. 1A
, the number of the coaxial lines
15
increases depending on the number of the irradiating elements
5
and soldering is needed to connect the irradiating elements
5
with the coaxial lines
15
. Thus, the number of assembly steps is large and it is difficult to form a thin structure because of its stereo structure.
Further, the antenna shown in
FIG. 1B
uses electromagnetic coupling for connecting the connecting lines
16
extending from the Rotman lens pattern
8
with the irradiating elements
5
. In this case, if the distance between the Rotman lens pattern
8
and the irradiating element
5
is short, irradiation directivity may drop. On the other hand, if this distance is prolonged to avoid this phenomenon, the connecting line
16
is prolonged, so that reduction in the size of the power feeding substrate
6
becomes difficult to achieve and further, loss on the connecting line increases.
DISCLOSURE OF INVENTION
An object of the present invention is to provide a small beam scanning plane antenna which is excellent in terms of its thin structure and simplification of its assembly process.
To achieve the above object, the beam scanning plane antenna is formed by stacking a system connecting portion, a Rotman lens portion, and a beam scanning antenna portion in that order. The beam scanning antenna portion includes a power feeding substrate containing a plurality of antenna groups each constituted of an irradiating element, a power feeding line connected to the irradiating element and a first connecting portion connected electromagnetically to the Rotman lens portion; a first grounding conductor having-a first slot at a position corresponding to the position of the irradiating element; a second grounding conductor having a second slot at a position corresponding to the position of the first connecting portion; a first dielectric provided between the first grounding conductor and the power feeding substrate; and a second dielectric provided between the power feeding substrate and the second grounding conductor. The Rotman lens portion includes a Rotman lens substrate having a Rotman lens pattern, a second connecting portion, which is connected to the Rotman lens pattern, for connecting the Rotman lens pattern with the first connecting portion, and a third connecting portion, which is connected to the Rotman lens pattern, for connecting the Rotman lens pattern with the system connecting portion electromagnetically; a third grounding conductor having a third slot at a position corresponding to the position of the third connecting portion; a third dielectric provided between the second grounding conductor and the Rotman lens substrate; and a fourth dielectric provided between the Rotman lens substrate and the third connecting conductor. The Rotman lens portion and the beam scanning antenna portion are formed by stacking the third grounding conductor, the fourth dielectric, the Rotman lens substrate, the third dielectric, the second grounding conductor, the second dielectric, the power feeding substrate, the first dielectric and the first grounding conductor in that order.
According to the invention the system connecting portion comprises: a connecting substrate including a fourth connecting portion provided at a position corresponding to the position of the third connecting portion on the Rotman lens substrate and a connecting line for connecting at least the fourth connecting portion with the system; a fourth grounding conductor provided at least at a position corresponding to the position of the fourth connecting portion; a fifth dielectric provided between the third grounding conductor and the connecting substrate; and a sixth dielectric provided between the connecting substrate and the fourth grounding conductor, wherein the fifth dielectric, the connecting substrate, the sixth dielectric and the fourth grounding conductor are stacked in order.
According to the invention a plurality of antenna groups on the power feeding substrate, the Rotman lens pattern on the Rotman lens substrate, the second connecting portions, the third connecting portion, the fourth connecting portions and the connecting lines are formed by removing unnecessary copper foil by etching from copper coated lamination film in which copper foil is bonded to polyimide film as a foundation material.
According to the invention a foamed body having a relative dielectric constant of 1.1 is used for the first dielectric, the second dielectric, the third dielectric, the fourth dielectric, the fifth dielectric and the sixth dielectric.
According to the invention the first slot is a square whose one side is 0.59 times longer than free wavelength &lgr;
0
.
According to the invention an aluminum plate is used for the first grounding conductor, the second grounding conductor, the third grounding conductor and the fourth grounding conductor.
BRIEF DESCRIPTION OF DRAWINGS
FIG.
1
A and
FIG. 1B
are disassembly perspective diagrams showing a conventional example;
FIG. 2
is a disassembly perspective diagram showing an embodiment of the present invention;
FIG. 3A
is a diagram showing the directivity characteristic when beam is projected in the perpendicular direction;
FIG. 3B
is a diagram showing the directivity characteristic when the beam is inclined two degrees from the perpendicular direction; and
FIG. 3C
is a diagram showing directivity characteristic when the beam is inclined four degrees from the perpendicular direction.
REFERENCES:
patent: 3761936 (1973-09-01), Archer et al.
patent: 4899164 (1990-02-01), McGrath
patent: 6049311 (2000-04-01), Alexanian
patent: 6130653 (2000-10-01), Powers, Jr. et al.
patent: 5-29832 (1993-02-01), None
patent: 11-27033 (1999-01-01), None
patent: 2000-124727 (2000-04-01), None
English Language Abstract of JP 2000-124727.
English Language Abstract of JP 11-27033.
English Language Abstract of JP 5-29832.
Kanamaru Kiichi
Michisaka Takao
Mizugaki Hisayoshi
Ohta Masahiko
Greenblum & Bernstein P.L.C.
Hitachi Chemical Co. Ltd.
Nguyen Hoang V.
LandOfFree
Planar antenna for beam scanning does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Planar antenna for beam scanning, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Planar antenna for beam scanning will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3262286