FR2891424A1 - Signal processing device for signal transmission system, has divider`s input port and combiner`s output port situated on both sides of axis passing via center of active zone and parallel to direction of paths of signal propagating in zone - Google Patents

Abstract

The device has a divider (110) including an input port (111) and an output port (112), and a combiner (130) including an input port (131) and an output port (132). An active zone (120) is disposed between the output port of the divider and the input port of the combiner. The input port of the divider and the output port of the combiner are situated on both sides of an axis (Y) passing through a center of the active zone and parallel to the direction of paths of signal which propagates in the zone and is symmetrical with respect to the center. An independent claim is also included for a method for processing a signal.

Description

2891424 1

  The invention relates to a signal processing device.

  It relates in particular to a signal processing device comprising a divider having an input and an output port, a combiner having an input and an output port, and an active area disposed between the output port of the divider and the port. input access of the combiner.

  Such devices are for example used as a power amplifier.

  In this case, the active zone plays the role of amplification.

  For this purpose, it typically comprises a plurality of elementary amplifiers to which a signal is supplied by means of the divider.

  The signal having undergone different elementary amplifications is processed by the combiner, which essentially performs an addition of each of the amplified signals.

  This results in a high power amplifier parameterized by the number of elementary amplifiers making up the active area.

  An important parameter of such devices is the combination efficiency.

  The combining efficiency is defined by the ratio between the total output power of the device and the total sum of the output powers of each of the elementary circuits that make up the active area.

  In the preceding example, it is therefore the ratio between the total power supplied by the amplifier and the sum of the elementary powers provided by the elementary amplifiers of the active zone.

  This yield is known to depend on a number of important factors.

  A factor is, for example, a loss that may exist in access circuits to the active zone.

  These access circuits, typically circuits and / or electromagnetic and / or electronic devices, serve as an interface between the combiner or the divider and the elementary circuits.

  We know that to minimize these losses, it is possible to play on the structures and technologies of these access circuits.

  The combination efficiency also depends on how the illumination in the device is distributed.

  By illumination is meant a signal.

  Optimally, this illumination must be equi-distributed in amplitude in the active area, so that each elementary circuit is shown a signal having the same distortion.

  For this purpose, it is possible to play in known manner on geometrical parameters of the device.

  For example, one can play on distances between the components that make up this device.

  A known optimization of the distribution of illumination consists in making the global paths as equi-phase as possible.

  By this is meant that the difference in operation, or by analogy the phase shift, between the different signal paths traversing the divider on one side and the combiner on the other is as small as possible at each of them independently. .

  By way of explanation, FIG. 1 shows the part of a conventional device corresponding to the divider and to the active zone thereof.

  A signal 10 enters the device through the input port 20 and is distributed in different paths by the divider 30, such as for example the paths 11 and 12.

  The signal 10 thus crosses, according to said paths, the output port of the divider 30, then propagates in the active area 40.

  As can be seen in this figure, the paths 11 and 12 have a different length between their starting point 50, which corresponds to a phase center 50, and the output port of the divider.

  It is this difference which constitutes the difference in market between these two signals and which must be classically minimized.

  Thus, it will be considered in the rest of the text that a path difference corresponds to a difference in length between a path of the signal 10 and that which has the shortest distance from the phase center 50 to the output port of the divider 30.

  By analogy, in the combiner it will be a difference in length between the path of the signal 10 and the one that has the shortest distance from the phase center 50 of the combiner at the output access to its access port. Entrance.

  In the example shown in FIG. 1, the path that has the shortest distance is path 11.

  Therefore, a difference in the divider will define a difference in length between any path and the path 11.

  It will also be noted that a difference in path AL and a corresponding phase shift AP are linked by the relation: AL * v = AP, where v is the speed of propagation of a wave in the structure.

  This is the reason why in the following description, it will be possible to reason with a path difference as well as with a signal phase shift.

  We now understand that the geometry of the divider and combiner can have a significant influence on the difference in operation.

  In particular, it can be seen that the maximum operating difference, that is to say the difference between the shortest and the longest path 11 in the divider or combiner, increases with the width of the active area 40 ( width in the X direction in Figure 1).

  As the width of the active zone 40 may depend on the number of elementary circuits 70 that compose it, a large number of these circuits induces a greater maximum difference in the path, which is a disadvantage.

  A known technique which makes it possible to reduce the above-mentioned difference in step problems consists in increasing the length of the divider and / or the combiner.

  In this regard, Figure 2 shows the same part of the device of Figure 1, but the divisor has this time a length L 'most important.

  By comparison, it can be seen that the difference in path 100 is much smaller than the path difference 60, thus illustrating that an increase in the length of the divider allows an improvement of this parameter.

  However, a disadvantage of such a method is that increasing the length induces at the same time an increase in insertions losses in the component in question, which in particular degrades the power output of the device.

  Another disadvantage is that the equi-amplitude and equiphase settings are not independent, a compromise is necessary. And, this compromise does not maximize power.

  Another disadvantage is that this method is relatively inconsistent with a number of other requirements that a specification may impose.

  This may in particular be a constraint in terms of compactness, cost, etc. Another technique is known which involves associating a specific circuit with each of said access circuits to the active zone.

  In this regard, reference may be made to US Pat. No. 4,291,278, which proposes, in particular, to minimize the phase differences between the paths of a signal by inserting transmission lines of varying length at each access circuit to compensate for an to one the differences of market.

  Although interesting, this alternative does not sufficiently solve the aforementioned problems.

  In addition, the device of this document poses other additional problems, such as increased complexity posing particular problems of production and production, the circuits being all different from each other.

  Note also that the method described in this document is applied to a device whose elementary amplifiers must have different gains and deliver different powers, which again contributes to increasing the aforementioned complexity.

  The invention therefore aims to overcome at least the aforementioned disadvantages.

  For this purpose, the invention proposes a signal processing device comprising a divider having an input and output port, a combiner having an input and output port, and an active area disposed between the port of the divider and the input port of the combiner, characterized in that the divider and the combiner are arranged so that in cooperation they minimize the phase differences associated with the different signal paths between the input and output ports. output of the device.

  The invention also proposes a method for processing a signal traversing a divider, an active zone and a combiner, characterized in that both the phase of the paths in the divider and the phase of the corresponding paths are adapted in the combiner so that the sum of the phase of each path in the divider and of each corresponding path in the combiner is substantially equal.

  Thus, in the invention, neither transmission lines nor specific circuits are used in addition to the components initially used for the device.

  On the contrary, it is advantageously the divider and the combiner themselves which combine to minimize the differences in the path of the signal paths and therefore the phase differences.

  More precisely, this advantage is obtained thanks to their cooperation.

  This device is simple and compact.

  Moreover, the method of the invention is simple to implement, in particular by the fact that the settings to obtain equi-amplitude and equi-phase are made almost independent.

  Another advantage is that the method of the invention depends little on the technologies used.

  In particular, it is applicable to devices using various technologies, for example conventional 3D (three-dimensional), spatial, quasi-optical, etc. technologies. Another advantage is that the performance of the method and the devices thus produced are insensitive to the number of elementary circuits constituting the active zone.

  In other words, the dependence of the operating difference mentioned above as a function of the width of the active zone is rendered substantially zero, at least the smallest possible.

  The invention thus makes it possible to produce high-performance devices comprising an increased number of elementary circuits.

  Other aspects, objects and advantages of the invention will appear better on reading the following description of the invention, with reference to the appended drawings, in which: FIG. 1 illustrates a difference in a divider of a conventional device seen in longitudinal section, - Figure 2 illustrates a difference in step which has decreased when using a divider having a length greater than that of the divider of Figure 1, - Figure 3 is a device according to the invention. seen in longitudinal section, the active zone comprising elementary circuits arranged on superposed trays along a width of said zone; - FIG. 4 is another device according to the invention seen in longitudinal section, the active zone comprising elementary circuits arranged on trays disposed next to one another along a length of said zone; FIG. 5 graphically shows by way of nonlimiting example of the differences operating frequencies observable at the level of the output port of a divider of a device of the prior art, and for different ratios between the length of the divider and the width of the active zone; FIG. 6 graphically shows as a non-limitative example of the differences in the operation observable at the output port of a combiner of a device of the prior art, and for different ratios between the length of the combiner and the width of the zone active, - Figure 7 shows graphically by way of non-limiting example a comparison of the differences in operation observable at the output port of a divider of a device of the invention and the prior art, and for different ratios between the length of the divider and the width of the active zone, FIG. 8 graphically shows, by way of nonlimiting example, a comparison of the differences in operation observable at the level of the output port of a combiner. a device for According to the invention and the prior art, and for different ratios between the length of the combiner and the width of the active area, FIG. 9 is a table showing the results obtained in a modeling example.

  As shown in section in FIG. 3, a device for processing a signal according to the invention comprises a divider 110, an active zone 120 and a combiner 130.

  Divider 110 and combiner 130 have input ports 111 and 131 and outputs 112 and 132, respectively.

  These ports 111 and 132 correspond to phase centers.

  As can be seen, such accesses define a boundary zone where it can be considered that, depending on the case, the signal enters or leaves the component considered.

  The active area 120 is between the output port 112 of the divider and the input port 131 of the combiner.

  It has itself an input port and an output port, but these are confused with the splitter output and the combiner input ports, respectively.

  The active zone 120 extends over a width denoted W defined by two upper ends 121 and lower 122.

  These two ends are respectively at an ordinate + W / 2 and W / 2 in an orthonormal coordinate system (YOX), where Y is an axis of the coordinate system parallel to a main propagation direction of a signal in the active area 120, 0 is the center of the active area and X is an axis orthogonal to Y, that is, an axis extending along the width of the device.

  The active zone comprises active elementary circuits arranged on a plurality of supports 140.

  As illustrated in FIG. 3, these supports 140 are installed one above the other along the axis X, thus along the width W of the active zone.

  Figure 4 shows a variant where the supports 140 are installed next to each other along the Y axis, thus according to the length of the device.

  A signal that enters the divider 110 through its input port 111 propagates along a plurality of paths to the input port of the active area.

  FIG. 3 shows, by way of nonlimiting example, a path 200 of the signal traversing in particular the divider 110.

  This signal then propagates in one of the elementary circuits of the active zone 120.

  In the example of FIG. 3, the path 200 of this signal is identified by its ordinate x in the reference (YOX).

  When the signal reaches the output port of the active area 120, it enters the combiner following the corresponding path 200.

  As shown in FIG. 3 again, A (x) is the length of a path in divider 110 of ordinate x and B (x) the length of the corresponding path in the combiner.

  According to one aspect of the invention, it is not necessary to arrange for the differences in operation of the different signal paths to be minimized as soon as the signal enters the active zone, therefore at the level of the output port of the divisor.

  Minimized, negligible or substantially zero path differences are understood to mean operating differences below a predetermined value.

  In the same spirit, it is also not necessary to arrange for them to be so when the signal travels through the combiner.

  On the contrary, surprisingly, the differences in the divider level, for example, can take non-zero values.

  According to one aspect of the invention, the differences in the operation between the input and output access of the device must be minimized globally, and not locally.

  For this purpose, in one embodiment of the invention, the divider and the combiner may be arranged so that the sum of each path between the input and output ports of the divider and each corresponding path between the accesses input and output of the combiner is substantially equal, ie the most similar possible.

  By way of nonlimiting example, the divider 110 and the combiner 130 are arranged so that the difference in path of the path 200 in the divider, added to that of the corresponding path 200 in the combiner, is equal, as far as possible, to the the difference in path of another path 201 of ordinate x1 added to that of its corresponding path 201.

  Consequently, the result of these additions is substantially equal to the same predetermined constant, so that the variations in the path differences become substantially zero, or negligible.

  A non-limiting example of an arrangement according to the invention is proposed in FIGS. 3 and 4 already discussed.

  As can be seen, the input ports of the divider 110 and the output of the combiner 130 are located on either side of the Y axis. More precisely, the input port 111 of the divider 110 is located in the reference (YOX) at a coordinate (L0 / 2 L1; H1) while the output port of the combiner 130 is at a coordinate (L0 / 2 + L2; H2), with the proviso that: - H1 is the shortest distance between the input port 111 of the divider 110 and the Y axis, - H2 is the shortest distance between the output port 132 of the combiner 130 and the Y axis, - L1, L2 the shortest lengths signal path traversing the divider and the combiner, respectively, and - LO the length of the active area.

  The coordinates of the ports 111 and 132 located on either side of the Y axis are therefore determined so that the sum of the lengths A (x) and B (x) of the paths in the divider and the combiner are the most constant. possible.

  Using trigonometric relations and considering the shape of the divider 110 and the combiner 130, the lengths A (x) and B (x) of the different x-ordinate paths can be expressed in the following mathematical form: A (x) _ V (H1 x) 2 + L12, and B (x) = - \ / (H2 + x) 2 + L22 (2) It should be noted from the foregoing that the invention only targets the cases where H1 and H2 are different from 0, whereas the devices of the prior art are aimed on the contrary only the case where H1 and H2 are equal to 0.

  It will be further noted that the cases where H1 = H2 and / or L1 = L2 correspond to variants of the invention for which the input port of the divider and the output port of the combiner are in fact symmetrical with respect to the center O of the reference (YOX).

  And in this case, we have: B (x) = A (x). (1) FIG. 5 graphically shows the differences in the operation of the different x-ordinate paths calculated at the output port of the divider of a device of the prior art of the type represented in FIGS. 1 and 2, these differences being normalized with respect to the width W of the active zone.

  Moreover, FIG. 6 graphically shows the global differences in the run of the various x-ordinate paths, calculated at the output port of the combiner of the device of the prior art, these differences being normalized with respect to the width W of the active zone.

  As will be understood, there is therefore a special case: H1 = H2 = 0, and furthermore: L1 = L2 = L Finally, the networks of curves in these figures correspond to different predefined L / W ratios.

  It will be noticed from the evolution of these curves that the normalized path difference A (x) -A (0) / W of a path increases with the absolute value of the ordinate x of this path.

  In addition, the higher the L / W ratio, the lower the differences in operation.

  This illustrates what was mentioned above, namely that increasing the length of the divider and / or the combiner makes it possible to reduce to a certain extent the differences in the path of the divider and / or the combiner.

  However, it is recalled that this method has drawbacks such as that of increasing the losses in these two components.

  A design of such a device of the prior art therefore requires a delicate compromise.

  FIG. 7 graphically shows the gait differences of the various x-ordinate paths, calculated at the output port of the divider of a device of the invention, these differences being normalized with respect to the width W of the zone active.

  And FIG. 8 graphically shows the overall operating differences of the various x-ordinate paths calculated at the output port of the combiner of the device of the invention, these differences being normalized with respect to the width W of the zone. active.

  Finally, the networks of curves on these two figures correspond to different predefined H / W ratios (H for height and W for width).

  It should be noted that here the ratio L / W remains unchanged (L for length) (for example L / W = 0.4 for these cases).

  It will be further noted that the two curves TA1 and TA2 correspond to a device of the prior art, the value of H1 and H2 being equal to 0.

  As can be seen, a comparison of the curves of FIG. 7 shows that the differences in the level of the output of the divider of the device of the invention are often greater than those represented by the TA1 curve of the art. prior.

  However, it is at the level of the device (FIG. 8) that it can be seen on the contrary that the results obtained with the invention are the best.

  Indeed, the curves relating to the device of the invention are all below the curve TA relative to the device of the prior art.

  The overall operating difference entering the input and output access of the device is therefore reduced compared with that of the device of the prior art.

  And it is clear that it is the cooperation of the divider and the combiner of the invention that makes it possible to obtain such an improvement.

  According to FIG. 8 again, it can also be seen that the derivative of the curves relating to the device of the invention is smaller than that of TA2.

  Consequently, the variations in the overall operating differences in the different devices of the invention are also smaller than those in the device of the prior art.

  It can also be seen from Figures 7 and 8 that as the H / W ratio increases, control of the difference in operation at the divider output port and the combiner output port is improved.

  Indeed, the curve corresponding to H / W = 1 is quasi-linear, like the dashed curve which corresponds, for the same H / W ratio, to the operating difference B (X) - B (0) / W at level of the output port 132 of the combiner.

  Given that A (X) = B (-X) and B is an odd function, the sum of these two curves is a substantially flat curve whose points are located around the constant zero, which corresponds to the goal research.

  Again, Figure 8 clearly illustrates this improvement.

  Indeed, the curve corresponding to H / W = 1 is substantially flat and much lower than the curve TA2 in the range of abscissa considered.

  Referring now to the table of FIG. 9, the results obtained from a device of the prior art and of the invention have been reported by way of nonlimiting example, the latter having not been optimized. in this example.

  More precisely, these are results obtained by electromagnetic modeling on a frequency point of a device of the prior art and of the invention, said device being associated with four elementary circuits connected in parallel in the active zone.

  Sij parameters in the module and in the phase of the divider as well as the combined efficiency of the two analyzed devices were calculated.

  The variations of the values of the arguments of the parameters Sij show in particular that, with respect to the invention, the phase-shifts between the paths at the level of the input access of the elementary circuits can be significant, at least higher than those observed in the device. of the prior art.

  Nevertheless, after comparison, in particular, the combination efficiency is observed that the said variations are very well controlled in the invention, which ultimately makes it possible to improve performance.

  Indeed the device of the invention has a yield of 94.5% against 92% for that of the prior art.

  Of course, the present invention is not limited to the embodiment described above and shown in the drawings.

  In particular, the elements that make up the device of the invention and which are shown in the figures may have different shapes. For example, the divider may have a generally curved or rectilinear shape.

  A generally rectilinear shape may consist of a line segment between the inlet and the outlet of the divider or several line segments inclined relative to one another.

Claims (6)

  A signal processing device (10) having a divider (110) having an input (111) and output (112) port, a combiner (130) having an input port (131), and output (132), and an active area (120 disposed between the output port (112) of the divider and the input port (131) of the combiner, characterized in that the input ports (111) of the divider and output (132) of the combiner are on either side of an axis Y, passing through the center O of the active zone (120), and parallel to the direction of the paths (200) of the signals that propagate in this zone (120), and are symmetrical with respect to said center O. 2. Signal processing device according to claim 1, characterized in that the paths (200) of a signal traversed in the divider and the combiner are characterized by the following equations A (x) and B (x), respectively: A (x) _ V (H1 x) 2 + L12, and B (x) _A / (H2 + x) 2 + L22 where x is the ordinate of a path (200) of the signal in an orthonormal center O and X axis, Y orthogonal and parallel to the direction of the signal paths in the active area (120), respectively; H, and H2 the shortest distances between the input port (111) of the divider and the Y axis and the output port (132) of the combiner and the Y axis, respectively; L, and L2 are the shortest path lengths (200) of the signal traversing the divider and the combiner, respectively.   3. Device for processing a signal according to one of the preceding claims, characterized in that the divider and the combiner have a symmetrical shape with respect to the center of the active zone O.   4. Device for processing a signal according to one of the preceding claims, characterized in that the active area comprises at least one means selected from the following group: - an amplifier, - a frequency multiplier, - electronic circuits arranged in parallel, like analog circuits.   8. Signal transmission system comprising a signal processing device according to one of the preceding claims.   9. A method of processing a signal (10) traversing a divider (110), an active zone (120) and a combiner (130), characterized in that both the phase of the paths (200) are adapted. in the divider, and the phase of the corresponding paths (200) in the combiner so that the sum of the phase of each path in the divider and of each corresponding path (200) in the combiner is substantially equal.   7. A method of processing a signal according to claim 6, characterized in that the active area (120) implements at least one of the following operations on the signal: amplify, 5 - multiply.