Communications: radio wave antennas – Antennas – With coupling network or impedance in the leadin
Reexamination Certificate
2003-03-03
2004-09-07
Phan, Tho (Department: 2821)
Communications: radio wave antennas
Antennas
With coupling network or impedance in the leadin
Reexamination Certificate
active
06788269
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an antenna device having a feed circuit that composes a plurality of beams in an array antenna which is arranged circumferentially.
BACKGROUND ART
A conventional antenna device will be described with reference to the accompanying drawings.
FIG. 9
is a diagram showing the structure of a conventional antenna device which is disclosed, for example, in Japanese Patent Laid-Open No. 61-169002.
Referring to
FIG. 9
, reference symbol
2
denotes an entire feed circuit; E
0
, E
1
, E
2
, E
3
and E
4
are antenna elements; H
2
is a 180-degree hybrid; Dm is a reflection free termination; Ac is an amplitude adjuster; Pc is a phase compensating circuit; H
1
is a 90-degree hybrid; Pb is a four-division divider; and F
1
, F
2
, F
3
and F
4
are feed terminals.
Then, the operation of the conventional antenna device will be described with reference to the accompanying drawings.
When an electricity is fed to the feed terminal F
1
by the hybrids H
1
, H
2
, the phase compensating circuit Pc and the amplitude adjuster Ac, the excitation amplitude phases of ja, exp(jp(&ohgr;), −exp(jp(&ohgr;)), j(1−a/2)A(&ohgr;), and j(1−a/2)A(&ohgr;) are fed to the five antenna elements E
0
, E
1
, E
2
, E
3
and E
4
, respectively.
Similarly, when an electricity is fed to the feed terminal F
2
, the excitation amplitude phases of ja, j(1−a/2)A(&ohgr;), j(1−a/2)A(&ohgr;), exp(jp(&ohgr;)), and −exp(jp(&ohgr;)) are fed to the five antenna elements E
0
, E
1
, E
2
, E
3
and E
4
, respectively.
Similarly, when an electricity is fed to the feed terminal F
3
, the excitation amplitude phases of ja, −exp(jp(&ohgr;)), exp(jp(&ohgr;)), j(1−a/2)A(&ohgr;), and j(1−a/2)A(&ohgr;) are fed to the five antenna elements E
0
, E
1
, E
2
, E
3
and E
4
, respectively.
Similarly, when an electricity is fed to the feed terminal F
4
, the excitation amplitude phases of ja, j(1−a/2)A(&ohgr;), j(1−a/2)A(&ohgr;), −exp(jp(&ohgr;)), and exp(jp(&ohgr;)) are fed to the five antenna elements E
0
, E
1
, E
2
, E
3
and E
4
, respectively.
With the above operation, the feed points of the feed terminals F
1
, F
2
, F
3
and F
4
are changed over, to thereby change over the beams of four kinds so as to conduct the transmit/receive of the signal.
In the above-mentioned conventional antenna device, in order that the four antenna elements E
1
to E
4
which are arranged circumferentially and the antenna element E
0
of one element which exists in the center thereof are excited to form the four kinds of beams, the twelve 90-degree hybrid circuits H
1
, the four 180-degree hybrid circuits H
2
, the four amplitude adjusters Ac, the four phase compensating circuits Pc and the four-division divider circuits Pb must be connected in multiple stages.
For example, even in the case where the array structure is made up of only four elements which are arranged circumferentially except for the one element which is disposed in the center of a circle, the four-division divider circuit Pb is merely removed. Therefore, there arise such problems that hardware becomes complicated, a connection loss becomes large and a signal to noise ratio (hereinafter referred to as “SN ratio”) is deteriorated.
The present invention has been made in order to solve the above-mentioned problems, and therefore an object of the present invention is to obtain an array antenna device which is capable of forming plural kinds of beams by a simple feed circuit structure in an array antenna which has four antenna elements which are arranged circumferentially and have a diameter which is uneven times of the half wavelength as a unit.
DISCLOSURE OF THE INVENTION
An antenna device according to claim
1
of the invention includes: first, second, third and fourth antenna elements which are arranged circumferentially at regular intervals; a first 90-degree hybrid having first, second, third and fourth terminals; a second 90-degree hybrid having fifth, sixth, seventh and eighth terminals; a third 90-degree hybrid having ninth, tenth, eleventh and twelfth terminals, and a fourth 90-degree hybrid having thirteenth, fourteenth, fifteenth and sixteenth terminals, in which: the third terminal of the first 90-degree hybrid and the ninth terminal of the third 90-degree hybrid are connected to each other; the fourth terminal of the first 90-degree hybrid and the thirteenth terminal of the fourth 90-degree hybrid are connected to each other; the seventh terminal of the second 90-degree hybrid and the tenth terminal of the third 90-degree hybrid are connected to each other; the eighth terminal of the second 90-degree hybrid and the fourteenth terminal of the fourth 90-degree hybrid are connected to each other; the eleventh terminal of the third 90-degree hybrid and the first antenna element are connected to each other; the twelfth terminal of the third 90-degree hybrid and the second antenna element are connected to each other; the fifteenth terminal of the fourth 90-degree hybrid and the third antenna element are connected to each other; the sixteenth terminal of the fourth 90-degree hybrid and the fourth antenna element are connected to each other; the passing phases of from the first terminal of the first 90-degree hybrid to the fourth terminal, from the second terminal to the third terminal, from the fifth terminal of the second 90-degree hybrid to the eighth terminal, from the sixth terminal to the seventh terminal, from the ninth terminal of the third 90-degree hybrid to the twelfth terminal, from the tenth terminal to the eleventh terminal, from the thirteenth terminal of the fourth 90-degree hybrid to the sixteenth terminal, and from the fourteenth terminal to the fifteenth terminal are set to 0 degree; and the passing phases of from the first terminal of the first 90-degree hybrid to the third terminal, from the second terminal to the fourth terminal, from the fifth terminal of the second 90-degree hybrid to the seventh terminal, from the sixth terminal to the eighth terminal, from the ninth terminal of the third 90-degree hybrid to the eleventh terminal, from the tenth terminal to the twelfth terminal, from the thirteenth terminal of the fourth 90-degree hybrid to the fifteenth terminal, and from the fourteenth terminal to the sixteenth terminal are set to 180 degrees.
An antenna device according to claim
2
of the invention includes: first, second, third and fourth antenna elements which are arranged circumferentially at regular intervals; a first 180-degree hybrid having first, second, third and fourth terminals; a second 180-degree hybrid having fifth, sixth, seventh and eighth terminals; and a third 180-degree hybrid having ninth, tenth, eleventh and twelfth terminals, in which: the third terminal of the first 180-degree hybrid and the fifth terminal of the second 180-degree hybrid are connected to each other; the fourth terminal of the first 180-degree hybrid and the ninth terminal of the third 180-degree hybrid are connected to each other; the seventh terminal of the second 180-degree hybrid and the first antenna element are connected to each other; the eighth terminal of the second 180-degree hybrid and the second antenna element are connected to each other; the eleventh terminal of the third 180-degree hybrid and the third antenna element are connected to each other; the twelfth terminal of the third 180-degree hybrid and the fourth antenna element are connected to each other the passing phases of from the first terminal of the first 180-degree hybrid to the fourth terminal, from the second terminal to the third terminal, from the fifth terminal of the second 180-degree hybrid to the eighth terminal, from the sixth terminal to the seventh terminal, from the ninth terminal of the third 180-degree hybrid to the twelfth terminal, and from the tenth terminal to the eleventh terminal are set to 0 degree; and the passing phases of from the first terminal of the first 180-degree hybrid to the third terminal, from the second terminal to the fourth terminal, from the fif
Chiba Isamu
Kihira Kazunari
Urasaki Shuji
Yonezawa Rumiko
LandOfFree
Simplified feed circuit for an array antenna device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Simplified feed circuit for an array antenna device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Simplified feed circuit for an array antenna device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3240053