close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3058080

код для вставки
Oct. 9, 1962
3,058,070
l. REINGOLD ETAL
MICROWAVE DUPLEXER
Filed Nov. 4, 1959
2 Sheets-Sheet l
F/G. /
5
\TRANSMITTER
3~DEC|BEL
COUPLED
6\
ANTENNA
8
4
3x
FERRITE
FILTER-LIMITER
_\
\
3-DECIBEL
COUPLED
STR lP-LINE
STRIP-LINE
DIRECTIONAL
DIRECTIONAL
COUPLER
FERRITE
FILTER-LIMITER
MY
031w
7-\
,
COUPLER
RECEIVER
DC MAGNETIC FIELD OF STRENGTH H
APPLIED TO FILTER-LIMITERS TO TUNE
THEM TO OPERATING SIGNAL STRENGTH
F/G. 3
REPAIcORWM'NE—R>
POWER 1N ANTENNA ARM
[8 ESSENTIALLY EQUAL TO
POWER OUT OF TRANS
SAFE LIMIT FOR DETECTOR
MITTER.
POWER OUT OF TRANSMITTER -—*
F/G. 4
ATENUIO
REc‘IN
FREQ —">
INVENTORS,
BY
JOHN L. CARTER
IRVING R ING‘OLD.
A TTUR/VE K.
Oct. 9, 1962
I. REINGOLD ETAL
3,058,070
MICROWAVE DUPLEXER
Filed Nov. 4, 1959
2 Sheets-Sheet 2
-
50Q3?%?
\M35I.,
_.252632
N
a“.0
2D5m0wt1P3h-:.C
INVENTORS
JOHN L. CARTER
IRV/NG REl/VG‘OLD.
A TTORNE Y.
United States Patent O?iice
'
3,058,070
Patented Oct. 9, 1962
1
2
3,953,079
system, and instead to cause re?ection of substantially all
of this energy through associated circuits to the common
MHCRGWA‘VE DUPLEXER
Irving Reingold, Deal Park, and John L. Carter, Ashury
antenna of the system for radiation thereby; and in signal
receiving intervals when the relatively low-power incom
Park, N.J., assignors to the United States of America as
represented by the Secretary of the Army
ing signal energy from the associated antenna is applied
thereto over the associated wire conductor, the resonator
Filed Nov. 4, 1959, Ser. No. 850,974
1 Claim. (Cl. 333-9)
(Granted under Title 35, U.S. Code (1952), see. 266)
will operate as a narrow-band ?lter tuned to the signal fre
quency to transmit essentially ‘all of that energy there
through with low loss to the associated receiver of the
The invention described herein may be manufactured 10 system for detection therein. The ?lter formed by the
and used by or for the Government for governmental
resonator also protects the receiver against spuriously
purposes, without the payment of any royalty thereon.
generated wave components outside the narrow band
The invention relates in general to microwave signal
width of the ?lter.
transmission systems, and particularly to duplexing equip
A balanced duplexer in accordance with one embodi
ment for directionally controlling signal transmission in 15 ment of the invention employs two such resonators tuned
microwave radar and other two-way radio communication
to the common operating signal microwave frequency of
systems employing a common antenna for transmission
the transmitter and receiver of the associated radar or like
nal transmission and reception at the same microwave
system by an applied transverse direct current magnetic
?eld of suitable strength, coupled through two directional
couplers of a conventional coupled-strip-line type in
balanced bridge relation with the transmitter, receiver and
common transmitting and receiving antenna of the as
and reception.
It is more speci?cally directed to such duplexing equip
ment of the balanced type for conditioning the associated
radar or similar radio system alternately for e?icient sig
frequencies.
sociated radar or like communication system and a suit
A general object of the invention is to produce the
able non-re?ective dummy load. In this duplexer, the
duplexing operations in such systems efficiently and eco 25 two “ferrite” resonators serve to provide the above-de
nomically with equipment that is relatively small, com
scribed power-limiting and re?ecting action on the out
pact and simple in construction; requires no movable de
going signal energy and ?ltering action on the incoming
vices, gas-?lled tubes or other thermionic devices for per
signal energy, respectively, and the directional couplers
forming the necessary signal control actions and, there
serve to provide the necessary combination of the incom
fore, has a relatively long, useful life; and has desirable
ing and the direct and re?ected outgoing signal energy
bandpass, tuning and timing characteristics.
components in phase and amplitude in transmission be
A primary object is to enable the use of the same
tween the resonators and the associated apparatus elements
antenna for signal radiation and reception at the same
of the communication system, to provide optimum duplex
microwave frequencies in a radar or like two-way radio
ing operation in that system.
communication system while preventing damage to the 35
A feature of the duplexer in accordance with the inven
sensitive detector elements in the receiver thereof by the
tion is that it is tunable over a wide range of microwave
high-power outgoing signal energy during signal transmit
ting intervals without reducing excessively the relatively
low-power signal input to the receiver during signal receiv
ing intervals.
signal frequencies by adjustment of the strength of the
direct current magnetic ?eld applied to the ferrimagnetic
40
A related but more speci?c object is to introduce signal
control actions into the branching circuits connecting the
signal transmitter and receiver to the common antenna in
such a radar or like communication system, such as to
enable system operation alternately for signal transmission 45
and reception with minimum adverse e?ects on the quality
of signal transmission and minimum damage to sensitive
system components by high-power signal energy.
material in the resonators.
These and the other features and objects of the inven
tion will be better understood from the following com
plete description thereof when it is read in conjunction
with the several ?gures of the accompanying drawings, in
which:
FIG. 1 shows a block schematic diagram of a balanced
duplexer embodying the invention applied to a microwave
radar or similar two-way radio communication system;
FIG. 2 is a combination perspective view of a practical
embodiment of the balanced duplexer of the invention
ferrimagnetic material as a function of incident wave 50 shown in FIG. 1, partially broken away to show structural
power level are utilized in the design of lumped-element
details more clearly, and a schematic diagram of the con
resonant networks or resonators employing such material
nections between the ?lter-limiter network or resonator and
for producing the necessary control actions in the duplexer
directional coupler portions thereof and the transmission
of the invention to attain the above objects. The active
apparatus of the associated radar or radio communication
element of each resonator comprises a small amount of a 55 system; and
ferrite or other ferrimagnetic material, such as single crys
FIGS. 3 and 4 show curves used to illustrate the opera
tal garnet, in the form of a small sphere or bead, con
tion of the duplexer of the invention in controlling the op
nected in, or closely electrically coupled to, a wire con
eration of the associated radar or like communication sys
ductor common to the transmission paths for the high
tem in the signal transmitting ‘and receiving conditions,
The non-linear phenomena exhibited by ferrites or other
power outgoing signal energy and the relatively low-power 60 respectively.
incoming signal energy of the same microwave frequency
Referring to FIG. 1, the balanced duplexer of the inven
in the associated radar or other radio communication sys
tion shown therein comprises the substantially identical
tem, the resonator being tuned to this signal frequency by
ferrite ?lter-limiter networks 1 and 2 connected between
the application of a direct current magnetic ?eld of suit
two four-terminal, 3-decibel directional couplers 3 and 4
able strength transversely to the sphere or bead. With the
65 of a conventional coupled-strip-line type. The input and
elements of this resonator properly proportioned, it will
output of the network 1 are respectively connected to one
operate in response to the incident high-power energy
of the four terminals of the directional coupler 3 and one
received over the associated Wire conductor from the trans
of the four terminals of the directional coupler 4; and the
mitter of a radar or similar system during signal transmit
input and output of the network 2 are respectively con
ting intervals to provide a power limiting action on that
70 nected to a second terminal of the directional coupler 3
energy such as to prevent transmission of any appreciable
and a second terminal of the directional coupler 4. ' The
amount of it through the resonator to the receiver of the
transmitter ‘5 and common transmitting and receiving an~_
3,058,070
0
tenna 6 of a radar or like radio communication system
4
to an odd multiple of a quarter wavelength of the operat
ing microwave signal frequency of the associated com
are respectively connected to the third and fourth terminals
of the directional coupler 3; and the receiver 7 of this same
system and a non-re?ective dummy load of such value as
to effectively balance the impedance of the antenna 6 are
respectively connected to the third and fourth terminals of
munication system. Similarly, the directional coupler
3 has two longitudinally-extending copper strips 12 and
13, identical with the strips 10 and 11 of coupler 3, em
bedded in the lower surface (bottom ground plane) of the
dielectric sheet 9, including two straight central portions
extending longitudinally in closely parallel relation to each
the directional coupler 4, so as to provide a balanced bridge
connection between these four system elements in which
the two ferrite ?lter-limiter networks 1 and 2 are respec
other for a given length representing the coupling region
tively included in oppositely-disposed bridge arms. As 10 and approximately equal to an odd multiple of a quarter
wavelength of the operating microwave frequency of the
indicated by the arrows so labeled, the ferrite ?lter-limiter
associated communication system. The dimensions of,
networks 1 and 2 are tuned to the common operating
and spacing between, the coupled copper strips or strip
microwave frequency of the transmitter and receiver of
lines in each of the directional couplers 3 and 4 are such
the associated system by the application transversely to
that each of these couplers has a minimum coupling of
-—3 decibels over a 2:1 frequency band. The frequency
range of each of these couplers may be 8500 to 12,000
mc., for example.
The transmitter 5 of the radar or like radio communica
tion system is connected through the 50-ohm coaxial con
nector 14 to one terminal 15 of the strip line 13 of di
these networks from an associated external source (not
shown) of a constant direct current magnetic ?eld of a
suitable strength H.
As shown in the practical embodiment of the balanced
duplexer of the invention in FIG. 2, the ferrite ?lter
limiter network 1 may comprise a lumped-element
resonator including as its active element a small sphere or
rectional coupler 3, and the common transmitting and
receiving antenna 7 of that system is connected through
bead 1a made from single crystal garnet and closely elec
trically coupled to a wire conductor 1b; and the ferrite
?lter-limiter network 2 may comprise a substantially
identical lumped-element resonator including as its active
a similar coaxial connector 16 to the adjacent terminal
17 of the strip line 12 of directional coupler 3. The re
element a similar small sphere or bead 2a made from
ceiver 6 of the communication system is connected
single crystal garnet and closely electrically coupled to
through the similar coaxial connector 18 to one terminal
the wire conductor 2b, the garnet sphere or beads 1a and
19 of the strip line 10 of the directional coupler 4, and
2a being subjected transversely to a direct current mag
netic ?eld of suitable strength to tune the resonators 1
and 2 to the same microwave frequency which is the com
a non-re?ective dummy load 8 made from any suitable
resistance material and of a resistance value su?icient to
match the impedance of the antenna 7 is connected to
mon operating frequency of the signal transmitter 5 and
the adjacent terminal 22 of the strip line 11 of the direc
tional coupler 4. The active element, the crystal garnet
sphere or bead 1a, of the resonator 1 is connected di
rectly to the other terminal 23 of the strip line 13 of
the directional coupler 3, and one end of the wire con~
ductor 1b of that resonator, coupled to the bead 1a, is
connected directly to the terminal 24 of the strip line 11
signal receiver 7 of the associated microwave radar or
radio communication system.
Each of the directional couplers 3 and 4 used in the ‘a
balanced duplexer of the invention may be of the general
coupled-strip-line type described in the article entitled,
“Coupled-Strip-Transmission-Line Filters and Directional
Couplers” by E. M. T. Jones and J. T. Bolljahn, in the
I.R.E. Transactions on Microwave Theory and Tech
of directional coupler 4, so as to provide a conductive
4:0
niques, vol. MIT-4 No. 2, April 1956, pp. 75-81, and
more completely in chapters 3 and 4 of the final report
on a research project on strip transmission lines and com
ponents sponsored by the Signal Corps Engineering
Laboratories, Fort Monmouth, NJ. (Contract DA63-039
SC-63232), published by the Stanford Research Institute
of Menlo Park, California in February 1957. As de
scribed in these publications, the basic directional coupler
of this type may comprise a pair of strip transmission
lines which are closely electrically coupled to each other ‘
over a portion of their lengths. This device, when its
four terminal pairs are terminated in the proper con
stant resistance, operates as a directional coupler with
loop connection through the resonator 1 between these
terminals of the two directional couplers 3 and 4. Simi
larly, the active element, crystal garnet sphere or bead
2a, of the resonator 2 is connected directly to the other
terminal 25 of the strip line 12 of the directional coupler
3, and one end of the wire conductor 2b of that resonator
is connected directly to the other terminal 26 of the strip
line 10 of directional coupler 4, so as to provide a conduc
tive loop connection through the resonator 2 between the
latter terminals of the two directional couplers 3 and 4.
The balanced duplexer of the invention as shown in
FIG. 2 and described above operates as follows: The
high-power outgoing signal energy of microwave fre
quency generated by the transmitter 5 of the associated
in?nite directivity and constant impedance theoretically
available at all frequencies and for all degrees of coupling.
The amplitude of the coupled wave varies approximately
sinusoidally with frequency, with maximum coupling oc
curring when the length of the coupling region is. an odd
radar or radio communication system in each signal trans
mounted thereon to a minimum.
face (top ground plane) of the dielectric sheet 9, includ
ing central straight portions extending longitudinally in
closely parallel relation to each other for a given length
1a and 2a resonators will be to increase the impedance
of these elements to a relatively high value and thus pro
vide a power-limiting action on these signal energy por
tions such that substantially none of the high-power signal
energy will be transmitted through the resonators and the
associated strip lines 10 and 11 to the receiver 6 and
representing the coupling region and approximately equal
dummy load 8. Thus, the sensitive detector elements in
mitting interval will be supplied through the coaxial con
nector 14 to the terminal 15 of the directional coupler 3
which, because of the coupling between its two strip
lines 12 and 13, will operate to split the supplied energy
into two equal energy portions differing in phase by 90
multiple of a quarter wavelength. If a signal is fed into
one terminal of the device, the coupled signal energy 60 electrical degrees. These two outgoing signal energy
portions will emerge at the terminals 23 and 25, respec
emerges from the two opposite terminals; no signal energy
tively, of that coupler and will be respectively applied to
emerges from the adjacent terminal.
the conductive loop formed by the coupling of the head
In the practical embodiment of the duplexer of the
In and wire conductor 1b of resonator 1, and to the con
invention illustrated in FIG. 2, the directional couplers 3
ductive loop formed by the coupling of the bead 2a and
and 4 are mounted on a sheet 9 of dielectric material, such
the wire conductor 2b of resonator 2. The effect of
as “Te?on,” the opposite faces of which form ground
the incident high-power signal outgoing signal energy
planes. The dimensions of this sheet 9 would be selected
portions on the garnet material in the active elements
such as to reduce the fringing effects in the couplers
As shown, the direc
tional coupler 4 has two longitudinally-extending thin,
?at copper strips 10 and 11 embedded in the upper sur
3,058,070
5
receiver 6 will be protected from the high-power outgoing
signal energy. Instead, the high impedance condition of
the garnet beads 1a and 2a will cause re?ection of sub
stantially all of the energy of the incident high-power out
energy will pass with low loss to the receiver 6 and
will be detected therein.
The desired frequency range of the resonators 1 and
2 operating as narrow-band ?lters in the low incident
going signal energy portions and be re?ected back through
terminals 23 and 25, respectively, into the copper strip
lines 12 and 13 of directional coupler 3. The re?ected
outgoing signal energy portions will be combined in phase
frequency band depending on the adjustment of the
strength of the applied direct current magnetic ?eld, as
illustrated by the curve of FIG. 4 showing the attenua
and amplitude by coupler 3 in such manner that two re
tion produced in the receiver arm of the balanced bridge
power condition can be tuned over a wide microwave
?ected energy portions appearing at the terminal 22 10 when the resonators are tuned to different frequencies
of the coupler connected to the dummy load 8 will be
f1, f2—in this wide range for different strengths H1, H;,,—
of the applied D.C. magnetic ?eld.
equal in amplitude and opposite in phase and will cancel
out, whereas the two re?ected energy portions of the out
going signal energy appearing at terminal 17 0f coupler
Although, in the duplexer of the invention as described
and illustrated, the active elements of the resonators em
3 connected to the antenna 7 will be of equal amplitude 15 ploy single crystal garnet material in the {form of small
and in the same phase so as to reinforce each other.
spheres or beads, it is to be understood that the inven
tion is not to be limited to this particular material and
Thus, substantially all of the re?ected outgoing signal en
shape of the elements and that any other fem'te or other
ergy will be transmitted to antenna 7 and will be radiated
thereby.
ferrimagnetic material in other shapes which would pro
The action of the balanced duplexer of the invention
in the signal transmitting condition is illustrated by
vide the same ?lter action and the same ?lter-limiting
the curve of FIG. 3 showing the signal power out of
the transmitter plotted against the signal power produced
action in response to incident low-power and high-power
signal energy, respectively, could be used in accordance
with the invention. Also, directional couplers of other
known types, for example, of the conventional short-slot
hybrid junction type, could be employed in the balanced
duplexer of the invention in place of the directional cou
plers of the coupled-strip-line type which have been illus
trated and described. Other modi?cations of the circuits
illustrated and described which are within the spirit and
in the receiver arm of the duplexer bridge. As shown
on this ?gure, the power appearing in the receiver arm
in response to the outgoing signal power of the trans
mitter will never exceed the safe limiting value of the
detector elements in the receiver, whereas the signal
power entering the antenna arm of the bridge will be
essentially equal to the power out of the transmitter. 30 scope of the invention will occur to persons skilled in
During the alternate signal receiving intervals of the
the art.
What is claimed is:
associated radar or similar radio system, the relatively
In combination with a radio communication system
low-power incoming echo or radio pulse energy, of the
including a transmitter and a receiver tor respectively
same microwave frequency as the operating frequency of
the transmitter, picked up by the antenna 7 of the sys 35 generating high-power outgoing signals of microwave fre
quency and detecting relatively low-power incoming sig
tem will be applied through coaxial connector 16 to
nals of the same frequency, a common transmitting and
terminal .17 of directional coupler 3 and, due to the
receiving antenna and duplexing means connecting said
coupling provided between the copper strip lines 12 and
antenna to said transmitter and receiver for conditioning
13 of that coupler, will be split into two equal energy
said system alterately tor signal transmission and recep
portions differing in phase by 90 electrical degrees which
tion, said duplexing means comprising two branching
will respectively emerge at terminals 23 and 25 of the
circuits each including a single crystal garnet resonator
coupler 3 and will be applied to the conductive loops
in the form of a spherical bead and positioned in gyro
formed by the coupling of the ferrite (crystal garnet)
magnetic coupling relationship between two orthogonal
active element Ila to wire conductor 1b of resonator 1
and the identical active element 2a to the Wire conductor 45 transmission lines, the impedance of said single crystal
garnet resonators in response to the high-power outgoing
2b of resonator 2, respectively. As the power level
of the incident incoming signal energy portions is rela
signals incident thereon in signal transmitting intervals
tively low and the resonators 1 and 2 are tuned to their
being high and causing said resonators to provide a
power-limiting action on these signals such as to prevent
frequency by the applied direct current magnetic ?eld,
the impedances of the active elements of the resonators 50 transmission therethrough of any appreciable amount of
their energy and instead to cause that energy to be
1 and 2 will be maintained at their normal relatively low
re?ected by the resonators, the impedance of said single
value for this condition. The ?lter actions of the
crystal garnet resonators in signal receiving intervals when
resonators 1 and 22 will predominate with the result that
the relatively low-power incoming signals are incident
the incident incoming signal energy portions will be
transmitted through these resonators operating as ?lters 55 thereon being low causing said resonators to operate as
a narrow-band ?lter tuned to said microwave frequency
to transmit therethrough substantially all of the incom
ing signal energy in its frequently-band range with low
loss, and directional coupler means connected to said
through the terminals 24 and 26, respectively, to the
copper strip lines 10 and 11 of directional coupler 4. 60 orthogonal transmission lines and operating to direct sub
stantially all of the re?ected outgoing signal energy in
The coupler 4 will operate the split each of the supplied
signal transmitting intervals to said ‘antenna for radia
incoming signal energy portions into two equal portions
tion thereby and substantially all of the ?ltered incoming
one of which will emerge at terminal 22 of that coupler
with low loss only in the narrow frequency range to
which the resonators are tuned. The outputs of the
two resonators 1 and 2 for this condition will be applied
signal energy through said resonators in signal receiving
connected to the dummy load 8 and the other at terminal
19 thereof connected through coaxial connector 18 to 65 intervals to said receiver tor detection therein.
the receiver 6. The two equal incoming signal energy
portions emerging at terminal 22 of coupler 4 will be
opposite in phase and will cancel. Any signal due to the
departure from ideal coupling will be dissipated in the
associated dummy load 8, whereas the two equal in 70
coming signal energy portions emerging lat terminal 19
of coupler 4 will be in phase and will therefore reinforce
each other. The resulting combined incoming signal
References Cited in the ?le of this patent
UNITED STATES PATENTS
2,586,993
2,849,685
Riblet ________________ __ Feb. 26, 1952
Weiss _______________ __ Aug. 26, 1958
2,850,624
Kales ________ __r _____ __ Sept. 2, 1958
2,916,712
2,920,292
Artuso ______________ __ Dec. 8, 1959
Scovil et al. _____________ Jan. 5, 1960
Документ
Категория
Без категории
Просмотров
0
Размер файла
660 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа