Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~1 :
ENERGY COUPLING DEVICE
sACKGROUND OF THE INVENTION
1. Field of the Invention
An object of the present invention is a devlce for the
coupling of energies, which can be used with metrical and
decimetrical waves.
Devices of this type are necessary in different cases:
for example, using a source, to make several amplifiers or
preamplifiers working equipotentially and in equiphase, or
else to summate the powers delivered by several
equipotential and equiphase preamplifiers so that, with the
power obtained, amplifiers are made to work equipotentially
and in equiphase, or else again to summate the powers
delivered by several amplifiers working equipotentially and
in equiphase to supply one and the same user, generally
formed by a sending antenna.
2 Descrlption of the Prior Art
.
In the case, for example, of amplifiers which are to
be made to work equipo-tentially and in equiphase, there are
distributors with one input and n outputs, associated with
impedance matching circuits by quarter-wavelength
transformers, which perform this operation accurately
inasmuch as all the amplifiers deliver the same power; but
iE one or more amplifiers break down, the resultant
mismatching disturbs, notably, the operation of the entire
~k
assembly, and it becomes necessary to shield the
amplifiers by means of insulation devices. Various
solutions have been used to achieve this purpose:
distributors have been associated with
circulator-type insulator devices using the gyromagnetic
properties of ferrites. This approach is theoretically an
ideal one, but, in practice, it has various drawbacks, such
as limitations on power and selectivity, and relatively
high losses in the circulators;
ring-type hybrid junctions, 3 d~ couplers etc~ have
been cascade-mounted, the amplifiers being connected, in
twos, to one and the same junction; excellent decoupling is
thus achieved between the amplifiers but this is a costly
approach, especially for a large number of amplifiers,
because of the number of hybrid junctions needed. Moreover,
the losses are high;
distributors have been associated with Wilkinson
type shielding devices; this is a fairly efficient
approach. However, it has proved to be very difficult to
apply it for use with microwave bands with a large number
of ampliEiers.
SUMMARY OF THE INVENTION
An aim oE the invention is to obtain the same
advantages as those related to cascade-mounted hybrid
junctions while, at the same time, reducing the drawbacks
,
~e minimum.
This is got by suitably associating hybrid junctions
with distributors.
According to the invention, there is provided a device
5 f or the coupling of energies, between m energy sources,
where m is a positive whole-number value, and n users,
where n is a positive whole-number value, and where m+n is
greater than 2, comprising m first and n second 90-degree,
3 dB hybrid circuits, each having a f irst, a second, a
l O chird and a f ourth port, the f irst and the second ports as
well as the third and the fourth ports of each hybrid
circuit forming pairs of con jugated ports, m+n balancing
loads respectively associated with the m+n hybrid circuits
and a first and a second distributor with the m inputs n
15 outputs, the two distributors being equipotential and in
equiphase, and having the same inputs/outputs phase shift,
the m f irst circuits having their m f irst inputs coupled
espectively to the m sources, their n second ports
connected respectively to the m loads, their m third ports
20 connected, respectively, to the m inputs of the first
distributor, their m fourth ports connected, respectively,
-to the m inputs of the second distributor, the n second
circui ts having their n f irst ports respectively connected
to the n outputs of the f irst distributor, their n second
25 ports respectively connected to the n outputs of the second
distributor, their n third ports respectively connected to
the n loads and their n fourth ports respectively connected
to the n users.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood, and
its other characteristics will emerge, from the following
description and the appended figures, of which:
- figure 1 shows a coupling device between amp~ifiers
and a user;
~ figure 2 shows a coupling device between
preamplifiers and the amplifiers of figure l;
- figure 3 shows a coupling device between a source
and the preamplifiers of figure 2.
The corresponding elements in the various figures are
15 designated by the same references.
MORE DETAILED DESCRIPTION
In the following description, as well as in the
claims, reference is made to 90-degree 3B hybrid junctions,
comprising two pairs of conjugated ports. The term "pair of
20 conjugated ports" of the junction must be understood to
mean two of the four ports o~ the junction such that, if
the matched loads are connected to it, there is practically
no coupling between the other two ports of the circuit, the
other two ports moreover forming also a pair of conjugated
25 ports; and always when matched loads are connected to one
~2~g~4
of the pairs of conjugated ports, the power applied to one
of the two conjugated ports of the other pair goes out by
the ports of the pair to which matched loads are connected,
at equal power but with waves in phase quadrature. In the
diagrams, the pairs of conjugated ports of the 90 degree 3
ds hybrid junctions, shall be respectively marked 1-2 and
3-4; these junctions are directional couplers in the
assemblies which have been used as examples for the present
description, and these 90 degree 3 dB directional couplers,
shall be called, in the rest of the description "3 dB
couplers" or even "couplers". However, it should be noted
that, without going beyond the scope of the invention,
these couplers may consist of any other equivalent
junctions such as, for example, magic T junctions or hybrid
ring junctions associated with phase shift elements of
appropriate value.
Figure 1 shows the diagram of a coupling device which
can be used to supply an antenna A with the sum, short of
losses, of the energies yiven by n amplifiers, El to En (in
the example described n was equal to 8 and the amplifiers
each had an output power of 1 kilowatt). The outputs of the
amplifiers, E1 to En, are respectively connected to the
ports 1 of n 3 d~ couplers, Dl to Dn. Between the ports 2
of the couplers Dl to Dn and the ground, there are mounted
the ba1ancing resistors Rdl to Rdn which form matched
loads. The ports 3 of the couplers Dl to Dn are
respectively connected to the inputs l to n of a
distributor Cl wi-th n inputs and one output. In the same
way, the ports 4 of the couplers Dl to Dn are respectively
connected to the inputs l to n of a distributor C2 with n
inputs and one output; the distributors Cl, C2, are
equipotential and in equiphase, and have the same
input/output phase shift. These distributors are also
called 0 dividers. The outputs of the distributors Cl, C2,
are respectively connected to the ports l and 2 of a 3 dB
coupler, B, the port 3 of which is connected to the ground
by a balancing resistor Rb and the port 4 of which is
connected to the antenna A, the latter having an impedance
matching circuit (no-t shown).
15If the assembly according to figure l is to work
accurately, the amplifiers El to En should deliver
equipotential and equiphase signals; there are known
assemblies to obtain this result, but it is also possible,
as shall be seen with the help of figures 2 and 3, to
achieve this result with asssemblies according to the
invention, since what has to be done, each time, is to
distribute the power of one or more sources to one or more
users which become sources in the next amplification step;
; thus, the amplifiers of figure 1, which are the users of
energy from the preamplifiers of figure 2, are also the
.
79~
energy sources for the user which is the antenna A of
figure 1.
ln normal operation, namely with the amplifiers El to
En, delivering equipotential signals in equiphase, the
power of the amplifier Ei (i: whole number which may assume
any value from 1 to n) is divided into two equal parts, but
with a 90 aperiodic phase shift, by the coupler Di:
- a part U/ ~ which appears on the port 3 of
the coupler Di (U being the voltage corresponding to the
power given by the amplifier Di which, besides, is the same
irrespectively of the value assumed by i from 1 to n~;
- a part U/~.exp(-j~/2), where exp~-j~/2)
represents the exponential of -j~/2, with j=~r;
all the power of the signals appearing at the port 3 of the
couplers Dl to Dn is applied to the distributor Cl, and all
the power of the signals appearing at the port 4 of the
couplers Dl to Dn is applied to the distributor C2. If uc
is the phase change resulting from the crossing of the
distributors Cl and C2 , the signals at the ports 1 and 2
oE the coupler B respectively have the form:
U/~exp (j ~c).
U/v~.exp-j~/2~c)
givîng respectively , at the ports 3 and 4 of the coupler
U/2.exp(j ~c)+U/2.exp-j (~ ~ c) null signal.
95~
U/2.exp~ /2~c)+U/2.exp-j(~/2 ~ c), a signal representing
the recombined total power.
Thus, the assembly- formed by the couplers and the
distributors of figure 1, constitutes a shunting of the
ports 1 of the couplers, Dl to Dn, towards the port 4 of
the coupler B when the ports 2 of the couplers, Dl to Dn~
and the port 3 of the coupler B are perfectly decoupled.
The assembly according to figure 1 works as a power
summator, the power at the port 4 of the coupler B being
the sum, short of losses, of the powers given by the
amplifiers El to En. It should be further noted that the
assembly according to figure is reversible, except for the
amplifiers El to En.
However, what is the degree of insulation of the
amplifiers El to En with respect to one another? The signal
that comes from an amplifier Ei (i: whole number capable of
assuming any value from 1 to n) and has reached the inputs
i of the dividers Cl and C2 is divided into three parts:
- one part transmitted towards the ports 1 and 2 of
the coupler V;
- one part reflected towards the amplifier Ei;
~ one part retransmitted towards the other ampliflers;
When all the signals ~iven by the amplifiers El to En
are equipotential and in equiphase, only that part
transmitted towards the ports 1 and 2 of the coupler B
exists, while the other parts are null. When this is not
the case owing to an imbalance in amplitude or phase
between the amplifiers, or owing to a failure of one or
more amplifiers, any signal coming from a faulty amplifier
Ei and reflected by the distributors Cl and C2, or
retransmitted to the other amplifiers, gets recombined and
appears at the ports 2 of the couplers Dl to Dn where it is
absorbed by the protective loads formed by balancing
resisters Rdl to Rdn. The assembly according to figure 1
thus provides perfect protection to the amplifiers from any
imbalance and even from any total stoppage of one or more
amplifiers. And the ratio between the normally available
total power and the ef~ectively available total power is,
barring losses of the system, as for an association of
cascade-mounted couplers ;
n2/(n-n~)2
where n' is the number of malfunctioning amplifiers.
Figure 2 shows how the n amplifiers El and En are
supplied from m equipotential and equiphase preampliEiers,
20 Jl to Jm. The assembly comprises the m preamplifiers,
followed by m 90-degree 3 dB couplers, Hl to Hm, followed
by two identical equipotential and equiphase distr.ibutors
Gl and G2 with m inputs and n outputs followed by n
90-degree 3dB couplers, Fl to Fn, followed by n amplifiers,
25 El to En. Between the ports 2 of the couplers, Hl to Hm,
~æ~
and the ground as well as between the ports 3 of the
couplers Fl to Fn and the ground, there are connected
balancing reslstors, Rhl to Rhm and Rfl to Rfn.
That part of the assembly of figure 2, going from the
preampli.fiers, Jl to Jn, to the inputs of the distributors
Gl, G2, corresponds to that part of the assembly according
to figure 1, included between the amplifiers, El to En, and
the inputs of the distributors Cl and C2; the shielding of
the preamplifiers, Jl to Jn, against any abnormal operation
by one of them is thus provided.
That part of the assembly of figure 2, going from the
outputs of the distributors, Gl, G2, to the inputs of the
amplifiers, El to En, corresponds to that part of the
assembly according to figure 1 between the inputs of the
lS distributors, Cl and C2, and the outputs of the amplifiers,
El to En, namely a part used in reverse to the direction of
its use according to figure 1, in taking advantage of its
reversibllity. This part of the assembly of figure 2
enables an equipotential and equiphase supply of the
amplifiers El to En.
Figure 3 shows how the preamplifiers, Jl to Jn, can be
supplied equipotentially and in equiphase from a source
represented by a single amplifier, N, to the input of which
a signal S is applied. The assembly has the amplifier N,
followed by a 90-degree 3dB coupler, M, followed by two
1~97g~
identical, equipotential and equiph~se distributors Ll, L2,
with one input and m outputs, followed by m 90-degree 3 dB
couplers, Kl to Km, followed by m preamplifiers, Jl to Jm.
Between the port 2 of the coupler M and the ground, as well
as between the ports 3 of the couplers Kl to Km and the
ground, balancing resistors R and Rkl to Rkm are connected.
That part of the assembly according to figure 3,
included between the output of the source N and the inputs
of the preamplifiers Jl to Jm, corresponds to that part of
the assembly according to figure 1 included between the
antenna A and the outputs of the amplifiers, El to En,
which is used, therefore, through its reversibility, in the
reverse direction of its use according to figure 1. This
assembly can be used for an equipotential and equiphase
supply of the preamplifiers, Jl to Jm.
The invention is not restricted to the example
described. It can be applied generally to the equipotential
and equiphase supply of n users by m sources of energy with
m and n as positive whole numbers and m+n as greater than
2.
