Wave transmission lines and networks – Wave mode converters
Reexamination Certificate
1999-12-03
2002-05-14
Pascal, Robert (Department: 2817)
Wave transmission lines and networks
Wave mode converters
C333S125000, C333S135000
Reexamination Certificate
active
06388537
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an antenna feeding system installed at a station such as an earth station for tracking and controlling an artificial satellite hereinafter referred to as a satellite, particularly relates to an antenna feeding system for shared application of a circularly polarized wave and a linearly polarized wave.
2. Description of the Prior Art
FIG. 9
is a block diagram for a conventional antenna feeding system.
1
is a 180° polarizer for rotating the plane of polarization of a linearly polarized wane signal transmitted from a satellite,
2
is a 90° polarizer for passing through the signal transmitted from the satellite leaving as it is when the wave is linearly polarized and for resolving the signal into perpendicularly intersecting two linearly polarized waves when the wave is circularly polarized,
3
is a rotary joint for rotating the 180° polarizer
1
and the 90° polarizer
2
, respectively,
4
is an orthomode transducer for dividing the perpendicularly intersecting two waves to each wave,
5
is a diplexer for dividing a signal consisting of signals having different frequencies and
6
a
,
6
b
,
7
a
, and
7
b
are signal terminals for outputting signals with respective polarization and respective frequency among different polarizations and frequencies.
A description on a conventional antenna feeding system will be given. By means of the rotary joint
3
, the 90° polarizer
2
is coupled rotatably with the 180° polarizer
1
and with the orthomode transducer
4
, and the 90° polarizer
2
is capable of setting an arbitrarily chosen angle with respect to the orthogonally intersecting polarized wave terminals of the orthomode transducers
4
. Within the 90° polarizer
2
, a dielectric plate is disposed and the angle of this dielectric plate with respect to the orthomode transducer
4
becomes a setting angle of the 90° polarizer
2
. As to the orthomode transducer
4
, two transducers of
4
a
and
4
b
are disposed on the output side of the 90° polarizer
2
, and these transducers
4
a
and
4
b
have orthogonally polarized wave terminals, respectively. The diplexers
5
a
and
5
b
are connected with the orthomode transducers
4
a
and
4
b
and the signals processed in the diplexers
5
a
and
5
b
are arranged to be outputted to the signal terminals
6
a
,
6
b
,
7
a
and
7
b
. To these terminals
6
a
,
6
b
,
7
a
and
7
b
, frequency and polarization of input and output signals are allocated and respective signals, whose frequency and polarization are coincident with allocated ones, are inputted or outputted.
Subsequently, an operation of the conventional antenna feeding system for receiving a signal from a satellite will be described with reference to FIG.
9
. Concretely, at first operation of receiving circularly polarized wave signals having frequencies of f
1
and f
2
and then receiving linearly polarized wave signals having frequencies of f
1
and f
2
will be described.
Now, the linearly polarized wave is the one having a polarization whose direction of propagation of an electric field is directed to a constant direction, and there exists orthogonally intersecting linearly polarized waves such as a vertically polarized wave V and a horizontally polarized wave H; the electromagnetic wave having orthogonally intersecting planes of polarization such as a vertically polarized wave V and a horizontally polarized wave can be utilized for transmission of different information by treating those waves as independent waves even when the frequencies are identical, and thus the reclamation of frequencies utilizing the orthogonally polarized wave becomes feasible. The circularly polarized wave is the one which is composed of a horizontally polarized wave H and a vertically polarized wave V with mutual phase difference of 90°, and depending on lag or lead of the phase difference, the circularly polarized wave becomes either a right handed circularly polarized wave R or a left handed circularly polarized wave L. Planes of the polarization of these waves rotate with period of the carrier wave clockwisely or counter-clockwisely and those waves intersect perpendicularly capable of carrying different information as independent electromagnetic waves, respectively.
Next, a description will be given on the operation of the antenna feeding system when it receives circularly polarized waves having frequencies of f
1
and f
2
transmitted from a satellite. Rotate the 90° polarizer
2
by the rotary joint
3
and set the dielectric plate within the 90° polarizer
2
so that the plate makes an angle of 45° with respect to the orthogonally intersecting polarized wave terminals of the orthomode transducers
4
a
and
4
b
. For receiving a circularly polarized wave, the 180° polarizer
1
can be set to an arbitrarily chosen position. The circularly polarized wave transmitted from a satellite is inputted to the 90° polarizer
2
through the 180° polarizer
1
. When the circularly polarized wave inputted to the 90° polarizer
2
is right handed R, upon converting the right handed circular wave R to a vertically polarized wave V, it is outputted to the orthomode transducer
4
a
, and is transmitted to the diplexer
5
a
together with its energy.
On the other hand, when the circularly polarized wave inputted to the 90° polarizer
2
is left handed wave L, this wave is converted to a horizontally polarized wave H and is outputted to the orthomode transducer
4
b
though the orthomode transducer
4
a
and transmitted to the diplexer
5
b
together with its energy.
Through procession of the 90° polarizer
2
, the incoming circularly polarized wave is identified as to whether the wave is right handed circularly polarized wave or left handed one.
The diplexer
5
a
and
5
b
perform procession of dividing the vertically polarized wave V and the horizontally polarized wave H with respect to the frequency, and divided signals through diplexers
5
a
and
5
b
are outputted to the signal terminal
6
a
,
6
b
,
7
a
and
7
b
: if the incoming signal is the right handed circularly polarized wave R with frequency of f
1
, the signal is outputted to the terminal
6
a
and if the signal is left handed circularly polarized wave L with a frequency of f
2
, the signal is outputted to the terminal
7
a.
Likewise if the incoming signal is right handed circularly polarized wave R with a frequency of f
2
, the signal is outputted to the terminal
6
b
and if the incoming signal is left handed L with a frequency of f
2
, the signal is outputted to the terminal
7
b
. In this way, the incoming signal can be drawn through an appropriate terminal depending on the frequency and polarization of the incoming wave.
Next, operation on reception of linearly polarized waves having frequencies of f
1
and f
2
will be described.
Rotate the 180° polarizer
1
by means of the rotary joint
3
and set the dielectric plate within the 180° polarizer
1
so that the angular position becomes one corresponding to the angular position of the plane of the receiving linearly polarized wave. Concretely, when the plane of the polarization of the incoming wave makes an angle a with respect to the vertical axis, the dielectric plate within the 180° polarizer is positioned so that it makes angle of a, and the 90° polarizer
2
is set so that the dielectric plate within it makes angle of 0° or 90° with respect to the orthogonally intersecting polarized wave terminals of the orthomode transducers
4
a
and
4
b
. For reception of a linearly polarized wave, the 90° polarizer
2
can allow the linearly polarized wave passing through untouched by setting the 90° polarizer
2
to 0° or 90°.
A linearly polarized wave transmitted from a satellite is inputted to the 180° polarizer
1
and is converted so that the polarization plane becomes either vertical or horizontal.
Thus converted linearly polarized wave through the 180° polarizer
1
passes through the 90° polarizer
2
as is and is inputted to the orthomode transducers
4
a
and
4
b
. When the inputted line
Glenn Kimberly E
Pascal Robert
Rothwell Figg Ernst & Manbeck
LandOfFree
Antenna feeding system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Antenna feeding system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antenna feeding system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2915138