Wave transmission lines and networks – Coupling networks – With impedance matching
Reexamination Certificate
2000-02-09
2002-06-04
Bettendorf, Justin P. (Department: 2817)
Wave transmission lines and networks
Coupling networks
With impedance matching
C333S260000
Reexamination Certificate
active
06400234
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention relates to a strip line feeding apparatus for feeding a high frequency signal to a strip line.
2. Description of the prior art
FIG. 33
is a plan view of an example of the strip line feeding apparatus in the prior art, which was disclosed in Japanese Patent Application JP-A-8-250912. In the figure, reference numerals
1
,
2
,
3
,
4
,
10
,
40
denote, respectively, a strip conductor pattern, an arc like conductor pattern, a through-hole for inner conductor, a tip portion of the strip conductor pattern
1
, and a through-hole for a fixing bolt.
FIG.
34
and
FIG. 35
are cross sectional views of
FIG. 33
, along the lines a—a′ and b—b′, respectively. In these figures, reference numerals
5
a
,
5
b
denote first and second dielectric substrates, and the reference numerals
6
a
,
6
b
denote first and second ground conductor patterns, respectively. Reference numeral
20
denotes a coaxial connector.
The strip conductor pattern
1
is formed on one side of the first dielectric substrate
5
a
, and the first ground conductor pattern
6
a
is formed on the other side of the first dielectric substrate. The second ground conductor pattern
6
b
is formed on one side of the second dielectric substrate
5
b
. The first and the second dielectric substrates
5
a
,
5
b
are disposed one over another to form a strip line. The cross sections of the strip line are shown in
FIGS. 34
,
35
. The first and second ground conductor patterns
6
a
,
6
b
are disposed at the outer sides of the strip line, respectively.
Reference numerals
20
,
7
,
8
,
9
denote, respectively, a coaxial connector, a central conductor of the coaxial connector, a dielectric portion of the coaxial connector, and an outer conductor of the coaxial connector.
The through-hole for inner conductor
3
is disposed at the tip portion of the strip line pattern
10
, and the arc like conductor patterns
2
are formed on the first and second dielectric substrates at the side opposite to the side where the first and second ground conductor patterns are formed, so that the arc like conductor pattern
2
surrounds the through-hole for inner conductor
3
.
A plurality of the through-holes for outer conductor
4
are disposed along the inner border of the arc like conductor pattern
2
. The through-holes for outer conductor
4
penetrate the arc like conductor pattern
2
and connect the first and second ground patterns
6
a
,
6
b
, which are disposed at the upper and lower surfaces of the dielectric substrates. The plurality of the through-holes for outer conductor
4
form a cage having a substantially cylindrical form. The through-hole for inner conductor
3
and the through-holes for outer conductor
4
form a coaxial line structure, the characteristic impedance of which is substantially equal to that of the coaxial connector
20
and that of the strip line.
The central conductor
7
of the coaxial connector
20
is inserted into the through-hole for inner conductor
3
from the side of the first ground conductor pattern
6
a
of the dielectric substrate
5
a
. And the central conductor
7
is soldered to be fixed to the through-hole
3
so as to electrically contact thereto.
The outer conductor
9
of the coaxial connector
20
electrically contacts to the first ground conductor pattern
6
a
of the dielectric substrate. By the way, the central conductor
7
is supported by the dielectric portion
8
of the coaxial connector so as to be held in the inner space of the outer conductor
9
of the coaxial connector.
The through-hole
40
for a fixing bolt has dimensions identical to that of the threaded holes disposed in the flange of the coaxial connector
20
so that the flange of the coaxial connector
20
can be fixed to the first and second dielectric substrates
5
a
,
5
b
, by means of fixing bolts, which can penetrate the holes.
A high frequency signal is supplied from the coaxial connector
20
to the strip conductor pattern
1
, through the through-hole for inner conductor
3
. The provided signal propagates along the strip line.
The ground signal flows from the outer conductor
9
of the coaxial connector
20
into the first ground conductor
6
a
on the upper surface of the dielectric substrate
5
a
. A part of the ground signal flows in the first ground conductor
6
a
, which is disposed along the strip line conductor pattern
1
. And the rest flows into the second ground conductor
6
b
through the through-hole for outer conductor
4
, and flows in the second ground conductor
6
b
, which is disposed along the strip line pattern
1
.
The coaxial line structure formed by the through-hole for inner conductor
3
and the through-holes for outer conductor
4
has dimensions substantially identical to that of the coaxial connector so that high frequency signals propagated in the coaxial line can be fed effectively to the strip line.
The strip line feeding apparatus in the prior art has drawbacks that the electromagnetic field is disturbed and the electromagnetic wave reflection characteristic is deteriorated. That is because there are discontinuous structures at the junction portion between the central conductor of the coaxial connector
20
and the through-hole for inner conductor
3
, as well as at the junction portion between the through-hole
3
and the strip conductor pattern
1
.
Furthermore, the junction portion between the coaxial connector
20
and the through-hole for inner conductor
3
is arranged in the inside of layered substrates, as a result, the fixing process such as soldering at the junction is difficult in the prior art. Especially when the structure in the prior art is applied in multi-layered substrates, it is necessary to dispose hidden blind through-holes. This entails to a complicated fabrication process.
SUMMARY OF THE INVENTION
An object of the present invention is to eliminate the above-mentioned drawbacks.
Another object is to propose a strip line feeding apparatus, which has a good reflection characteristic in the high frequency region.
Another object is to propose a strip line feeding apparatus, which can be easily fabricated.
The objects are attained by the strip line feeding apparatus described in the independent claims.
In an embodiment of the present invention, the strip line feeding apparatus comprises:
a first dielectric substrate, on one surface of which a strip conductor pattern is disposed, and on the other surface of which a first ground conductor pattern is disposed;
a second dielectric substrate, on one surface of which a second ground conductor pattern is disposed, the first and the second substrates are disposed one over the other so as to form a strip line so that the first and second ground conductor patterns are disposed at the outsides of the strip line;
a through-hole for inner conductor, which is connected with the tip portion of the strip conductor pattern and is penetrating the first dielectric substrate;
through-holes for outer conductor, which are disposed around the through-hole for inner conductor and are connecting the first and second ground conductor patterns disposed on the upper and under surfaces of the strip line;
and a signal feeder comprised of a signal conductor and a ground conductor, the signal conductor is electrically connected with the strip conductor pattern through the through-hole for inner conductor, and the ground conductor is electrically connected with the first and second ground pattern through the through-holes for outer conductor;
wherein a serial high impedance portion is disposed near to the connecting portion between the strip conductor pattern and the through-hole for inner conductor.
In an embodiment of the present invention, the high impedance portion is a portion disposed near to the tip portion of the strip conductor pattern, where the width of the strip conductor pattern is narrowed.
In an embodiment of the present invention, the high impedance portion is a hole disposed in the area of the second ground conductor of the second dielectr
Miyazaki Moriyasu
Ohhashi Hideyuki
Tahara Yukihiro
LandOfFree
Strip line feeding apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Strip line feeding apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Strip line feeding apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2938203