MXPA99000858A - A phase control device - Google Patents

Abstract

A phase control device, for providing a plurality of phase values, for utilisation by any system having a number of input/output ports with signals requiring control of their relative phases. The phase control device is constructed from phase shift elements electrically connected to a system of electrically interconnectedswitches separated off from the phase shift elements. The result is a reduction in the number of phase shift elements and switches as compared to conventional phase shifters and a simplification of the resulting architecture, a feature of significant importance in chip miniaturization.

Description

A PHASE CONTROL DEVICE DESCRIPTION OF THE INVENTION The present invention relates to phase control devices in general, and to phase control devices as they apply to particular phase-array antennas. Phase control devices play an important role in communications in general and in radars, and in satellite communications in particular. In the art, plane antennas disposed in phase are known to communicate with satellites that can be mounted on moving platforms. For certain such applications, the flat phase array antenna may comprise a few hundred radiation elements. This results in the use of a few hundred corresponding phase shifters, one for each radiation element. Due to the large number of phase shifters required, the phase arrangements by themselves are thus costly. Therefore, there is a need to reduce the number of phase shifters required for a given number of radiation elements of an in-phase arrangement. In the following description and claims, reference is made to phase shifters and phase control devices as applied to phasing array antennas. This is done for illustration clarity only and in no way should be construed as a limiting property of the phase control devices of the invention that can be used by any system having a plurality of input / output ports with signals that require control. of its relative phases. With reference to the phase shifters implicitly refers to the phase shift elements and the switches that constitute the phase shifters; thus reducing the number of phase shifters required for a given task which involves reducing the number of phase shifting elements and switches that constitute it. It is an object of the present invention to provide a phase control device that reduces the number of phase shifters required in a given application compared to prior art techniques. In addition to the reduction of the number of phase shift switching elements, another object of the present invention is the simplification of the resulting architecture wherein the reduced number of phase shift elements is separated from the reduced number of switches, which is a characteristic of significant importance in the miniaturization of the chip.

In accordance with the present invention, there is provided a phase control device for providing a plurality of phase values, comprising: a plurality of electrically interconnected phase shift elements; and a plurality of switches electrically interconnected by a plurality of first conductor lines and a plurality of second conductor lines, such a plurality of switches electrically connected to the plurality of phase shift elements by means of such plurality of second conductor lines. If desired, the phase shift elements and the switches can be divided into phase control units, the phase shift elements in each phase control unit are electrically interconnected and the switches in each phase control unit are they also electrically interconnect only the switches within the same phase control unit and the phase shift elements thereof. In addition, if desired, all phase control units are connected in parallel. Optionally, all phase control units are connected in series.

Alternatively, some of the phase control units are connected in series while others are connected in parallel. Also, if desired, the phase control units can be connected to the switches of an additional phase control unit. In a specific application of the invention, the phase shift elements, the switches and the first conductive lines are arranged on one side of a dielectric plate; while the second conductor lines are arranged on the opposite side of the dielectric plate. From r. According to an embodiment of the present invention, the phase control device further comprises, in a stratified formation in the direction of the part, a plurality of dielectric plates, each having front and rear faces, and wherein the plurality of phase shift elements, the plurality of first conductor lines and the plurality of second conductor lines, are disposed on the faces of the dielectric plates. According to one embodiment of the invention, the phase shift elements are connected in series. According to another embodiment of the invention, the phase shift elements are connected in parallel.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding, the invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings in which: Figure 1 shows an illustrative block diagram of a phased array antenna with each radiation element connected to a phase shifter; Figure 2 shows a phase shifter in the typical stage M; Figure 3a shows a single phase shifter of a phase shifter in step M in the "off" state; Figure 3b shows a single phase shifter of a phase shifter in step M in the "on" state; Figures 4a and 4b illustrate the terminology for counting the number of switches; Figure 5 shows an illustrative block diagram of a phased array antenna with a switching circuit and a phase shift unit; Figure 6 illustrates the structure of a phase control device; Figure 7 shows a perspective view of a portion of a phase control device according to an embodiment of the present invention; Figure 8 shows a schematic block diagram of a phase control device; Figure 9 shows a schematic block diagram illustrating phase compensation for a phase control device according to an embodiment of the present invention; Figure 10 shows an illustrative block diagram of a phase control device with a phase shift unit connected in a parallel. Figure 11 shows a cascade configuration of phase control devices connected in series. Draw attention first to Figure 1, showing an illustrative block diagram of a phased array antenna 1, comprising the radiation elements 2 N, designated by RI (I = 1, N), each connected through a phase shifter 4 corresponding to a power divider / combiner 6. Because there is a phase shifter connected to each radiation element, there are phase shifters N, designated by Pl (1 = 1, ...., N). Figure 2 shows a phase shifter 10 in the typical multistage stage M comprising M phase shift elements 12, designated by PEJ (JH = 1, ...., M), reference elements 22, switches 14 for introducing either the phase shift elements or the reference elements in the electrical path between the input / output ports 20, the control units 16, for operating the switches and a connected control bus 18 to the control units. Each phase shift element 12 introduces a different phase shift in the current flowing therethrough in relation to a current flowing through a corresponding element of the reference elements 22. Figure 3a shows a single phase shifter 30 of a multi-stage phase shifter, of the type shown in Figure 2, in the "off" state, where a certain phase is introduced into a stream flowing through the element 22 reference. The current enters and leaves the commutator through the input / output ports 31 of the commutator. On the other hand, Figure 3b shows the individual phase shifter 30 in the "on" state where a different phase is introduced into the current flowing through the phase shifting element 12. The single phase shifter 30 comprises two input and two output switches 14, each of which can serve as the input switch or the output switch since the phase shifter is bidirectional. The terminology for counting the number of switches is illustrated in Figures 4a and 4b. In Figure 4a, there are two switches, since the circuit 40 can be put in electrical connection with two circuits 41 and 42, while in Figure 4b, there is only one individual switch since the circuit 40 can be brought into electrical contact with only an individual circuit 43. In a unidirectional phase shifter, the number of switches can be reduced by replacing their two output switches with a balanced combiner, this results in losses within the combiner. However, a unidirectional phase shifter, when used in bidirectional applications, adds at least two external switches to the phase shifter (see, for example, British Patent No. 2158997 A). On the other hand, in certain implementations, such as the low-pass step-shifters, there are as many as six switches. Therefore, in general, the phase shifters of interest can have a total of two to six switches. In the following description, phase shifters having four switches will be considered. Returning to the phase shifter in stage M shown in Figure 2, it is clear that it contains a total of 4M switches. The number of phase combinations P obtainable from a phase shifter in step M is given by P = 2M. This relation can be derived by counting the number of combinations of the "on" and "off" states of the individual phase shifters M comprising the phase shifter in stage M. Therefore, in a phased array antenna, since whether linear or flat, comprising N radiation elements controlled separately, each connected to a phase shifter in stage M, there is a total of 4MN switches and MN phase shift elements. Likewise, each phase shifter in stage M provides 2M phase values, giving a total of 2MN phase values for the total antenna. In the phasing array antennas in general, and in particular in the millimeter wave and microwave phase array antennas, there is a large number of radiation elements and a correspondingly large number of phase shifters. A large number of phase shifters (in the previous example N shifters in the M-stage) not only results in the antenna being expensive, but also introduces redundancy in the layout design in phase due to the presence of a large number of identical phase shift elements. The present invention reduces the number of switches and phase shifting elements, required for a phased array antenna by providing a set of phase shifting elements that are shared by all radiation elements. This is achieved by connecting the set of phase shift elements to a switch system which in turn is connected to the radiation elements of the phasing antenna. Attention is now drawn to Figure 5 which shows an illustrative block diagram of a phased array antenna 50, comprising N radiation elements 51, designated by R1 (1 = 1, ...,), each connected to a switching circuit 52 which in turn is connected to a phase shift unit 53. The switching circuit 52 and the phase shift unit 53 taken together constitute the phase control device of the invention. Figure 6 illustrates the structure of the phase control device 60 according to one embodiment of the invention. The phase shift unit 53, according to this embodiment, comprises a plurality of phase shift elements 62 connected in series by the conductive lines 64. It should be noted that the phase shift elements 62 can be any suitable passive or active components or combinations thereof. The switching unit 52 comprises a plurality of switches 66, connected on one side, at the first terminals 67, to a plurality of first conductor lines 68 and on the other side, at the second terminals 69 to a plurality of second conductor lines 70. shown as dashed lines in the figures. It should be noted that in the figure, the first terminals 6-7 are shown as junctions with the first conductor lines 68. It should further be noted that the plurality of first conductor lines 68 do not physically intersect the plurality of second conductor lines 70. This can be accomplished, according to one embodiment of the present invention, placing the plurality of first conductor lines 68 and the plurality of second conductor lines 70 in separate planes. According to a specific embodiment of the invention, the two planes are substantially parallel. If the space between the planes is desired, it can be filled with a dielectric plate. The plurality of the second conductor lines 70 are plotted with dashed lines to indicate that they are in a plane different from that of the plurality of first conductor lines 68 in this specific embodiment. The switches 66 are shown in the same plane as the first conductor lines 68, so that the electrical connection between the switches 66 and the second conductor lines 70 is achieved by the conductive lines in the interplane (not shown) connected to the terminals 69. Connected to the first conductor lines 68 are the input / output ports 72 of the switching unit which, in the case of an in-phase arrangement, are connected to the radiation elements for radiating and receiving electromagnetic radiation. The phase shift unit 53 has, at one end, an input / output port 74 and is connected to the plurality of second conductor lines 70 through the conductive lines in the interplane (not shown) connected to the third terminals 76. In order to compare the number of phase shift elements and the switches required when using the phase control device 60 unlike the conventional N phase shifters in the individual stage M shown in Figure 1, it is assumed that in Figure 6 there are N input / output ports 72 and that there are 2M phase shift elements 62. Therefore, there are 2MN switches in the phase control device 60. Therefore, the saving in the number of switches when the phase control device 60 is used in comparison with a phase shifters in the conventional stage M is? S = 4MN-2MN, while the saving in the number of elements in the phase shift it is? P = MN-2M. For example, when N = 1000 and M = 3, then? S = 12000-8000 = 4000 and? P = 3000-8 = 2992. Figure 7 shows a perspective view of a portion of the phase control device 60 according to the embodiment of the invention in which the first and second conductor lines 68 and 70, respectively, are in separate planes. Each of the second terminals 69, shown in Figure 6, is constituted by a pair of second terminals 69a, 69b as shown in Figure 7 connected by the conductive lines 80 in the entreplane, shown with dotted lines. The switches 66, the first conductor lines 68 and the phase shift elements 62 together with the input / output ports 74 of the phase shift unit are shown located in a "top plane" 82, while the second lines conductors are shown in a "lower plane" 84. The terms "upper" and "lower" are used with reference to the illustration of the phase control device 60 shown in Figure 7 and do not refer to the actual orientation of the device. - phase control device in practice, which can be in any desired orientation. Each third terminal 76, shown in Figure 6, is constituted by a pair of third terminals 76a, 76b as shown in Figure 7 connected by the conductive lines 80 in the entreplane. The upper and lower planes 82 and 84 can be, for example, the opposite faces of a dielectric plate, by connecting the interplane of the conductive lines 80 that pass through the perforated holes through the dielectric plate. Although the plurality of first conductor lines 68 and the plurality of second conductor lines 70 are preferably located in separate planes so that there will be no direct contact between them, the switches 66 and the phase shift elements 62 can be located either in the upper plane, as shown, or both in the lower plane, or one of them in the upper plane and the other in the lower plane. It should be appreciated that the distribution of the various components, i.e., the switches 66, the phase shift elements 62, the conductor lines 64 and the first and second conductor lines 68 and 70, respectively, are not necessarily restricted to the opposite faces. of a single dielectric plate and that the phase control device of the invention can also be implemented by arranging the various components on a number of dielectric plates arranged in a stratified formation in the direction of the part as is well known in chip design . The distribution of the above components between the different dielectric plates may vary depending on the particular implementation. The operation of the phase control device for a series-connected phase shift unit will be illustrated with reference in FIG. 8, showing a schematic block diagram of a phase control device 90 having an input port 91. / output, a phase shift unit 92 connected in series comprising three phase shift elements 93, designated by PS1, PS2 and PS3, and a switching unit * 94 comprising twenty switches 95 designated "by SIJ (1 = 1, ...., 4; J = l, ...., 5) and five input / output ports 96 designated by AJ (J = l, ...., 5). The values of the phase shifters obtained from the phase shift elements will be indicated by psK (K = 1, 2, 3), that is, the phase shift element PS1 results in a phase shift of psl. , etc. For clarity consider the situation in which a current is input to port 91 of input / output (which therefore becomes a port of entry in this mode of operation) and where currents with several phases are going to be obtained in the input / output ports 96, which in this mode of operation play the role of output ports. When describing the operation of the phase control device it is. it will assume that, unless otherwise indicated, all switches 95 are off (ie, they are in the "off" state), ie, they are in the open circuit and there is no current flowing through them. In order to apply a current with a phase shift of ps3 to port A5, only switch S35 is turned on (ie, it switches from the off state to the "on" state). Similarly, to apply a current with phase ps3 to port A4, only switch S34 is turned on. In other words, in order to apply a phase current ps3 to the output port AJ (J = l, ...., 5) only the switch S3J is turned on (J = 1, ...., 5). In order to apply a current with a ps2 + ps3 phase to port A45, the input current has to pass through both phase shift elements PS2 and PS3, therefore, only switch S25 is turned on. In general, to apply a current with phase ps2 + ps3 to port AJ, only switch S2J is turned on (J = l, ...., 5). Similarly, to apply a current with one phase psl + ps2 + ps3 to port AJ, only the SIJ switch (J = l, ...., 5) is turned on. All phases are measured with respect to the phase of the current at port 91 of input. Clearly, the conductive lines 100 and 102 also introduce phase shifts and in varying amounts depending on which of the switches is turned on. For example, if switches S15 are turned on, the current passes through a relatively small length of the conductive line 102. On the other hand, if the switch Sil is turned on, the current passes through the entire length of the conductive line 102. Therefore, the lengths of the conductor lines connecting the switches to the conductor lines 100 and 102 have to be designed in a suitable manner to compensate for the phase shifts introduced by the passage of a current through the conductor lines 100 and 102. A possible approach to phase compensation is illustrated schematically in Figure 9 which shows a block diagram of the same device 90 of the phase control shown in Figure 8, with the only difference that the phase compensation elements 106 have been introduced into the conductive lines that connect the switches. It should be noted that in practice, the locations of the phase compensation elements 106 are not limited to those shown in Figure 9, the only limitation being that the correct phase compensation is introduced. Although the phase compensation elements 106 have been illustrated as additional path lengths, it will be appreciated that the phase compensation can be effected by any suitable phase shift component. Similarly, suitable phase compensation can also be introduced in Figures 6 and 7. The phase control device of the invention is illustrated with a phase shift unit connected in series. However, phase shift elements can also be connected in parallel. Figure 10 shows an illustrative block diagram of a phase control device 120 with a phase control shift unit 122 illustrated in parallel having the phase shift elements 123 connected in parallel commonly connected to the input / exit 124. For the sake of illustration, the switching unit 126 having the switches 128 and the input / output ports 129 has been taken identically to the switching unit 94 in Figure 8. For the sake of the illustration, the additional path lengths used For the phase compensation, as described above, they have not been shown in Figure 10. If a parallel connection of the phase shift units connected in series is desired, it can also be carried out. This can be done, for example, for the series connected phase shift unit illustrated in Figure 9 by connecting the input / output ports 91 in parallel. In situations where a large number of input / output ports are required for the switching units of the phase control device, it is sometimes useful to use a cascade configuration of the phase control devices. In other situations, it is useful to connect the phase control devices in parallel or in series, or in a combination thereof. For this purpose, a phase control unit is used from which phase control devices can be constructed. In other words, the phase shifting elements and the switches can be divided into the phase control units, the phase shifting elements in each phase control unit are electrically connected and the switches "in each phase control unit Only the switches within the same phase control unit and the phase shifting elements thereof are interconnected electrically, A cascaded configuration of the phase control units may comprise the phase control units with displacement units phase devices connected either in series or in parallel Figure 11 shows an illustrative block diagram of a cascaded configuration of the phase control units with the phase shift units connected in series. phase 140, 160, 180 and 200 respectively comprising the switching units 142, 162, 182 and 202 having the s respective input / output ports 144, 164, 184 and 204; and the phase shift units 146, 166, 186 and 206 having the respective input / output ports 147, 167, 187 and 207. The input / output ports 204 of the phase control units 200 are connected to the corresponding input / output ports 147, 167 and 187 of the phase control units 140, 160 and 180, respectively, as shown. In the specific application of a phasing antenna, the twelve input / output ports 144, 164 and 184 are connected to the radiation elements of the phasing antenna, and the port 207 of input / output is the port radio frequency input / output of the cascade switching units. The phase shift units 146, 166 and 186 may or not be identical, while the phase shift unit 206, in general, differs from each of the phase shift units 146, 166, 186. In a particular application, the phase shift units 146, 166 and 186, give rise to small phase shifts, for example, 5o, 10o and 15o, while the phase shift unit 206 results in large displacements of phase, for example, 30 °, 60 ° and 90 °. The cascaded configuration of the phase control units makes it possible to produce phase shift which are combinations of the large and small phase shifts. In another application, the phase shift units 146, 166 and 186 result in large phase shifts and the phase shift unit 206 results in small phase shifts. Figure 11 illustrates only one possibility of a cascaded configuration of the phase control devices, which is clearly not restricted to that shown and may have any number of input / output ports and any number of phase control units. In addition, Figure 11 illustrates a single-stage cascaded configuration that can be generalized directly to multiple cascaded configurations. Other useful embodiments may be constructed, for example, by taking the three phase control units 140, 160 and 180 and connecting them electrically in parallel or in series. These modes are not restricted to three control units or to control units with phase shift units connected in series. In addition, these modaliades can be constructed from a combination of phase control units some of which have phase shift units connected in series and some phase shift units connected in parallel. The same applies to cascading formations where one or more of the phase control units connected in series shown in Figure 11 can be replaced by the phase control units connected in parallel. The present invention has been described with some degree of particularity, but it should be understood that various alterations and modifications may be made without departing from the spirit and scope of the invention as claimed hereinafter.

Claims (10)

1. CLAIMS 1. A phase control device capable of providing a plurality of phase values, characterized in that it comprises: a plurality of electrically interconnected phase shift elements; and a plurality of switches electrically interconnected by a plurality of first conductor lines and a plurality of second conductor lines, the plurality of switches electrically connected to the plurality of phase shift elements by means of the plurality of second conductor lines. The phase control device according to claim 1, characterized in that the plurality of phase shift elements and the plurality of switches are divided into phase control units, the phase shift elements in each control unit of phase are electrically interconnected and the switches in each phase control unit are electrically and solely connected to the switches within the phase control unit, and to the phase shift elements of the phase control unit. 3. The phase control device according to claim 2, characterized in that the phase control units are connected in parallel. 4. The phase control device according to claim 2, characterized in that the phase control units are connected in series. The phase control device according to claim 2, characterized in that some phase control units are connected in series while others are connected in parallel. The phase control device according to claim 2, characterized in that the phase control units are connected to the switches of an additional phase control. The phase control device according to any of the preceding claims, characterized in that the plurality of the phase shift elements, the plurality of switches and the plurality of first conductor lines are disposed on one side of a dielectric plate; while the plurality of the second conductor lines is arranged on the opposite side of the dielectric plate. The phase control device according to any of claims 1 to 6, characterized in that it further comprises a stratified formation in the direction of the piece, a plurality of dielectric plates each having front and rear faces, and wherein the plurality of phase shifting elements, the plurality of switches, the plurality of first conductor lines and the plurality of second conductor lines are disposed on the faces of the dielectric plates. 9. The phase control device according to any of the preceding claims, characterized in that the plurality of phase shift elements are connected in series. The phase control device according to any of claims 1 to 6, characterized in that the plurality of the phase shift elements are connected in parallel.