System and method for managing the operation of a traveling wave tube amplifier

Abstract

A satellite system (10) is proposed, comprising a radio frequency signal amplifier (100) including a control and power supply module (1040) and a plurality of traveling wave tubes (1020-n). The module (1040) is configured to apply a zero anode voltage operating value to at least one of said tubes, generating a cathode current in response. The module (1040) is further configured to measure at least one sum of the cathode currents associated with said plurality of tubes, said at least one measurement of the sum of the cathode currents being implemented from a single measuring circuit (1044), and to determine at least one corrected zero anode voltage operating value, associated with said at least one of said tubes, from said at least one measurement of the sum of the cathode currents.

Description

Technical domain

[0001] The present invention relates generally to the field of traveling wave tube amplifiers, and in particular to a system and method for managing the operation of a traveling wave tube amplifier integrated into a satellite.

[0002] A traveling wave tube amplifier is used to transmit high-power radio frequency (RF) signals. A traveling wave tube amplifier consists of one or more traveling wave tubes controlled (or powered) by a high-voltage power supply.

[0003] As shown schematically in the figure 1 , a traveling wave tube comprises an input of a radio frequency signal RF IN and an output of a radio frequency signal RF OUT, a delay line 1021, electrodes comprising a cathode 1022, an anode 1023, also called "zero anode".

[0004] The cathode 1022 is brought to an operating temperature (typically 1000°C) by applying a voltage to the filament. When the cathode 1022 has reached the operating temperature, an electrical potential difference between the zero anode electrode 1023 and the cathode 1022 is applied. In particular, this electrical potential difference Va 0 is also called "zero anode voltage". When applying zero anode voltage Va 0 , the cathode 1022 emits a very dense electron beam 1024 called "cathode current" and noted I.

[0005] The delay line 1021 (also called a 'helix') is a spiral to which the RF IN microwave signal (or wave) is applied and through which the electron beam 1024 passes. When the electron beam 1024 passes through the helix 1021, an interaction is created between it and the RF signal, and part of the kinetic energy of the electrons in the beam 1024 is transferred to the microwave wave. The amplitude of the microwave wave at the RF OUT radiofrequency output of the helix 1021 is then amplified.

[0006] In particular, the value of the cathode current Iand the speed of the electron beam 1024 of a traveling wave tube makes it possible to predefine the performance of this tube. Some performances, called `RF performances', can be for example the saturation power, corresponding to the maximum power, and the frequency band of the radiofrequency output signal RF OUT, or the gain of the tube, corresponding to the ratio between the output power RF OUT and the power of the radiofrequency input signal RF IN. Other performance parameters of a tube can be its consumption or the energy dissipation which take into account the emissivity dispersion of the cathodes. A traveling wave tube can be associated with one or more operating points PF specific and / or optimal taking into account the performance of this tube. Thus, each operating point PF of a tube is associated a specific value of cathode current I.

[0007] Furthermore, the emissivity of a 1022 cathode varies mainly with the operating temperature of the 1022 cathode. The operating temperature of the 1022 cathode depends on the heating power of the filament. The emissivity of a 1022 cathode can also degrade depending on the operating time of the 1022 cathode. Variations in the emissivity of a 1022 cathode generate an average drift in the performance of this 1020-n tube over time. Thus, in order to maintain the electron flow of the 1024 beam and consequently the performance of the tube, it is thus necessary to adequately modify the zero anode voltage. Va 0 (or zero anode voltage operating value), especially for a given filament voltage.

[0008] Traditionally, to optimize the radiofrequency performance of a tube, the amplifier regulates the flow of electrons from the cathode of this tube from the direct measurement of the cathode current I of the tube.

[0009] Given the high voltage value to which the cathode is brought, a direct measurement circuit of the cathode current I is complex to implement, particularly given the high voltage insulation to be respected (for example 6 to 9KV).

[0010] In existing solutions, it is known to use several traveling wave tubes connected to a single high voltage power supply. In addition, to manage variations in operating points PF, i.e. variations in electron flow from the cathode of traveling wave tubes, the high voltage power supply performs individual regulation of the operating point for each tube PFof the tube. In particular, regulators specific to each tube measure the cathode current I for each tube, then transfer this value to a regulator potential (e.g. cathode voltage, anode voltage or ground) and a regulation circuit so as to generate a correction value, via a high voltage value of the tube anode. The mass, volume and cost of each of the direct cathode current measurement circuits I are thus multiplied by the number of tubes powered by the same power supply. This situation is particularly critical in certain areas of application, and in particular for traveling wave tube amplifiers used in the space sector.

[0011] Thus, there is a need for a traveling wave tube amplifier device capable of improving the operation management and adjustment of high voltage power supply compared to traveling wave tubes. Résumé de l'invention

[0012] The present invention improves the situation by providing a satellite system comprising a radiofrequency signal amplifier device, the amplifier device comprising a control and power supply module and a plurality N of traveling wave tubes. The control and power supply module is configured to apply, for at least one of the tubes, a zero anode voltage operating value. Va 0 n , the tube generating a cathode current I in response to the application of the zero anode voltage operating value Va 0 n .The control and power supply module is configured to measure at least a sum of the cathode currents M Σ I associated with the plurality N of traveling wave tubes, the at least one measurement of the sum of the cathode currents being implemented from a single measurement circuit. The control and power supply module is further configured to determine at least one corrected operating value of zero anode voltage associated with at least one of the tubes from the at least one measurement of the sum of the cathode currents.

[0013] Advantageously, each tube can be associated with an operating point PF n given associated with a cathode current setpoint value CI n and at a zero anode voltage setpoint CVa 0 n . The control and power module can be configured to apply the zero anode voltage setpoint to each tube CVa 0 n .The control and power module can be configured to activate a correction mode and to perform, during the correction mode: a single measurement of the sum of the cathode currents M Σ I associated with the plurality N of traveling wave tubes at the operating points PF n , for each tube, a determination of a corrected zero anode voltage value DVa 0 n from the single measured sum of the cathode currents M Σ I, of the cathode current setpoint CI n and the zero anode voltage setpoint CVa 0 n .

[0014] The control and power supply module can further be configured to apply, during the correction mode, to each tube the corrected value of the zero anode voltage DVa 0 n associated.

[0015] In embodiments, determining, for each tube, the corrected zero anode voltage value DVa 0 n can be performed from an estimated pervasiveness value DG n and the cathode current setpoint value CI n , the corrected zero anode voltage value DVa 0 n being defined by: DVa 0 n = CIK n DG n + 2 / 3 .

[0016] In other embodiments, determining, for each tube, the corrected zero anode voltage value DVa 0 n of the traveling wave tube can be done from a formula for the derivative of the cathode current with respect to the zero anode voltage of the tube at the operating point PF n .

[0017] The control and power supply module may be configured to additionally perform, during the correction mode, a determination of a drift ratio Q Σ Ifrom the single measured sum of the cathode currents M Σ I, and a sum of the cathode current setpoint values CI n of the plurality N of tubes.

[0018] According to some embodiments, applying, during the correction mode, the corrected value of the zero anode voltage DVa 0 n to the tube may be performed in response to detecting a performance drift of at least one of the plurality N of traveling wave tubes. the control and power module may comprise a data set comprising the recorded operating points PF n. The performance drift may be determined from a comparison of at least one estimated perveance value DG n with a setpoint perveance value CG n included in the data set. the control and power module may comprise a data set comprising the recorded operating points PF n. The performance drift may be determined from a comparison of the drift ratio Q Σ I with a drift threshold included in the dataset.

[0019] Advantageously, the performance drift can be determined from a comparison, for at least one of the tubes, of the corrected value of the zero anode voltage DVa0 n with the associated zero anode voltage setpoint value CVa0 n.

[0020] The control and power module may include an internal clock and the correction mode may be activated in response to detection of a predefined timestamp.

[0021] The control and power module may comprise an internal clock and a data set comprising the recorded operating points PF n. The control and power module may be configured to record in a calibration table and to associate a timestamp with the corrected value of the zero anode voltage DVa0 n and / or the estimated value of the perveance DG n , and to record, at each activation of the correction mode, the corrected value of zero anode voltage DVa0 n and / or the estimated value of perveance DG n in the data set. The control and power module may be further configured to calculate, for at least one tube of the plurality N of traveling wave tubes, a trend curve from the data set, and to estimate at least one predicted value of zero anode voltage PVa0 n and / or a predicted value of perveance PG n , associated with a predefined subsequent timestamp value.

[0022] Advantageously, each tube can be associated with a given operating point PF n associated with a zero anode voltage setpoint CVa0 n and a cathode current setpoint CIk n. The control and power supply module can be configured to activate a calibration mode and to perform, during the calibration mode: for a single tube of the plurality N of traveling wave tubes, an application of a first zero anode voltage value to the tube, a first measurement of the sum of the calibration cathode currents MΣIk 1< associated with the plurality N of traveling wave tubes, for the single tube, an application of a second given zero anode voltage value BVa0 n to the tube, a second measurement of the sum of the calibration cathode currents MΣIk 2< associated with the plurality N of traveling wave tubes, a comparison of the first and second measurements of the sum of the calibration cathode currents MΣIk 1< and MΣIk 2<;

[0023] The control and power supply module may be further configured to perform an update of the setpoint zero anode voltage value CVa0 n from the second given zero anode voltage value BVa0 n and based on the comparison.

[0024] In embodiments, the first zero anode voltage value may be a zero anode voltage reference value RVa0 n associated with a cathode current reference value RIk n . For the single tube, the comparison may be further performed from a calibration accuracy setpoint ε, the cathode current setpoint value CIk n and the cathode current reference value RIk n , such that | MΣIk 2< - MΣIk 1< - CIk n + RIk n | < ε.

[0025] Calibration mode can be activated in response to the detection of performance drift.

[0026] The invention also provides a method for controlling and powering a plurality of N traveling wave tubes. The method may be implemented in a satellite system comprising the traveling wave tubes. The method may comprise an initial step of applying to at least one of the tubes a zero anode voltage operating value Va0 n , the tube generating a cathode current Ik in response to the application of the zero anode voltage operating value Va0 n . The method may comprise the steps of: measuring at least one sum of the cathode currents associated with the plurality N of traveling wave tubes, the at least one measurement of the sum of the cathode currents being implemented from a single measurement circuit, determining at least one corrected operating value of zero anode voltage associated with at least one of the tubes from the at least one measurement of the sum of the cathode currents.

[0027] The system and method for managing the operation of a traveling wave tube amplifier according to the embodiments of the invention make it possible to simplify the implementation of the high voltage power supply compared to traveling wave tubes.

[0028] They provide an efficient solution, while limiting the manufacturing costs of the high-power radio frequency signal amplifier, and reducing the weight, volume and associated costs. Description of figures

[0029] Other characteristics, details and advantages of the invention will emerge from reading the description given with reference to the appended drawings given by way of example. There figure 1 is a diagram representing a traveling wave tube, according to the prior art. The figure 2 is a diagram showing a radio frequency signal amplifier, according to embodiments of the invention. The figure 3is a graph representing the evolution of the zero anode voltage to be applied as a function of a drift ratio, according to embodiments of the invention. The figure 4 is a flowchart representing steps of the method for managing the operation of traveling wave tubes, according to embodiments of the invention. The figure 5 is a flowchart representing steps of the method for managing the operation of traveling wave tubes, according to embodiments of the invention.

[0030] Identical references are used in figures to designate identical or similar elements. For clarity, the elements shown are not to scale. Detailed description

[0031] There figure 2schematically represents a device 100 comprising a plurality of N traveling wave tubes 1020-n and a control and power supply module 1040, according to embodiments of the invention.

[0032] The index `n' is used to denote the nth tube among the different traveling wave tubes, and is thus between 1 and N. The number N is greater than 1. For example and without limitation, the number N can be equal to 4 or 8.

[0033] The device 100 is a traveling wave tube amplifier, also called TWTA (acronym for the English expression “Traveling Wave Tube Amplifiers”). In an example of application of the invention to the satellite field, the device 100 can be embedded in a satellite system 10 and used to generate and transmit high-power radiofrequency signals to the ground, for example a telecommunications satellite.

[0034] The radiofrequency signal amplifier device 100 can deliver, for example, a few hundred watts, and operate at high frequency (or microwave). In particular, the amplifier device 100 can reach frequencies up to the W band of 100 GHz, for example.

[0035] A 1020-n traveling-wave tube, also called TOP or TWT (acronym for the English expression "Traveling-Wave Tube"), is an elongated vacuum tube used in the device 100 to produce low, medium or high power microwave amplifiers.

[0036] In embodiments, the device 100 may be a TWTA comprising multiple TWTs. In these embodiments, one or more traveling wave tubes 1020-n may comprise a housing incorporating M traveling wave tubes (not shown in the figures).

[0037] The device 100 further comprises one or more high voltage cables 1060-n connecting one or more tubes 1020-n to the control and power supply module 1040. A high voltage cable makes it possible to supply high voltage to at least one traveling wave tube. The control and power supply module 1040 comprises a high voltage power supply or an electronic power conditioner called EPC (acronym for the English expression “Electronic Power Conditioner”) configured to transform a low voltage supply voltage into multiple high voltages used to power the N traveling wave tubes 1020-n. The control and power supply module 1040 may comprise one or more DC-DC power converters supplied with energy by a power bus (or primary bus) 202 connected to an electrical power source 200 of the satellite 10.

[0038] Each 1020-n tube is associated with one or more specific and / or optimal operating points noted PF nj . The index `j' is used to denote a j-th operating point of a 1020-n traveling wave tube among the different operating points of the 1020-n tube, and is thus between 1 and J, J being greater than or equal to 1. Each operating point PF nj specific and / or optimal of a 1020-n traveling wave tube is associated with a cathode current setpoint value, and a zero anode voltage setpoint value. The rest of the description will be made with reference to a value of J equal to 1, an operating point of a 1020-n traveling wave tube then being noted PF n .

[0039] The control and power supply module 1040 is configured to apply to each tube 1020-n a cathode current setpoint value, denoted CVa 0 n .

[0040] For a 1020-n traveling wave tube, in response to the application of the set value CVa 0 n of zero anode voltage, the cathode 1022 generates an electron beam 1024 characterized by a specific value of the cathode current, noted I n .

[0041] In embodiments, the operating points PF n (Or PF nj) and the associated specific cathode current values ​​and the associated zero anode voltage setpoint values ​​may be recorded in a data set, for example in a storage unit 1042 internal to the control and power supply module 1040 and / or in a unit 300 external to the amplifier device 100. The external unit 300 may be, for example, programming equipment or the on-board computer noted OBC (acronym for the English expression "On Board Computer") of the satellite 10. The remainder of the description will be made with reference to a data set represented in the form of a calibration table, by way of non-limiting example. The external unit 300 may also receive instructions from a ground center.

[0042] As illustrated in the figure 2 , the control and power supply module 1040 includes a measurement unit 1044 configured to measure the value of the sum of the specific values I nof cathode current associated with all N traveling wave tubes 1020-n of the amplifier device 100 of radiofrequency signals. This value is also called hereinafter `sum of cathode currents' and noted M Σ I.

[0043] It should be noted that, for one or more 1020-n tubes, the specific value I n of the cathode current, generated in response to the application of the set value CVa 0 n zero anode voltage, may be different from the cathode current setpoint, noted CI n , associated with this setpoint value CVa 0 n zero anode voltage. A difference between the specific value I n of the generated cathode current and the set value CI n cathode current results from a variation in emissivity of the cathode 1022.

[0044] Thus, to maintain the performance of each of the traveling wave tubes 1020-n of the satellite 10, the control and power module 1040 can be configured to activate a correction mode and to perform, during the correction mode: a measure of the sum of the cathode currents M Σ I, and for each 1020-n tube, a determination of a corrected zero anode voltage value, noted DVa 0 n .

[0045] The control and power supply module 1040 is further configured to apply, during the correction mode and to each tube 1020-n, the corrected value DVa 0 n zero anode voltage.

[0046] The corrected value DVa 0 n zero anode voltage can be estimated, for example via a determination unit 1046 internal to the control and power supply module 1040, from the measured sum M Σ Icathode currents, setpoint value CI n cathode current and setpoint value CVa 0 n zero anode voltage.

[0047] In a first variant of the invention, the corrected value DVa 0 n zero anode voltage can be determined using a perveance definition formula G n of a 1020-n traveling wave tube as a function of cathode current and zero anode voltage. The perveance formula G n can be defined by the following equation (01): G n = Ik n Va 0 n 3 / 2

[0048] It should be noted that the persistence G n of a 1020-n traveling wave tube is specific to that 1020-n tube and is an image of the cathode emissivity. Thus, the perveance G n of the 1020-n traveling wave tube varies with the life of the 1020-n tube and may be associated with the specific and / or optimal operating points of the 1020-n tube.

[0049] In embodiments, the determination unit 1046 may be configured to estimate, for each tube 1020-n, the corrected value DVa 0 n of zero anode voltage from a perveance value, noted DG n , estimated based on the set value CI n cathode current of the 1020-n tube, as defined by the following equation (02): DVa 0 n = CIK n DG n + 2 / 3

[0050] Furthermore, the estimated value DG n of perveance of a 1020-n tube can be estimated from an estimated value of cathode current, noted THICK n and the zero anode voltage setpoint value CVa 0 n , as defined by the following equation (03): DG n = DIK n CVa 0 n 3 / 2

[0051] The estimated value THICK n cathode current in particular estimated from the measured sum M Σ I cathode currents.

[0052] In embodiments, the estimated value THICK ncathode current of tube 1020-n can be set from the set value CI n of cathode current and a drift ratio, noted Q Σ I, as defined by the following equation (04): DIK n = CIK n × Q ∑ IK

[0053] In equation (04), the drift ratio Q Σ I can be defined as the ratio of the measured sum M Σ I cathode currents on a sum Σ n CIK n setpoint values CI n cathode current on all 1020-n tubes. Thus, the drift ratio Q Σ I can be expressed according to the following equation (05): Q ∑ IK = M ∑ IK ∑ n CIK n

[0054] The expression of the corrected value DVa 0 n of zero anode voltage to be applied for each 1020-n tube can thus be simplified by combining the previous equations (02), (03), (04), and (05). In particular, the expression of the corrected value DVa 0 n of zero anode voltage can be simplified according to the following equations (06) or (07): DVa 0 n = CVa 0 n × 1 Q ∑ IK + 2 / 3 DVa 0 n = CVa 0 n × ∑ n CIK n M ∑ IK + 2 / 3

[0055] In a second variant of the invention, the corrected value DVa 0 n of zero anode voltage can be done using a formula for the derivative of the cathode current with respect to the zero anode voltage of the 1020-n tube at the operating point PF n . In particular, the corrected value DVa 0 n of zero anode voltage can be obtained from the following equation (08): DVa 0 n = CVa 0 n × 1 − 2 3 × Q ∑ IK − 1 DVa 0 n = CVa 0 n × 1 + 2 3 × 1 − M ∑ IK ∑ n CIK n

[0056] According to equations (07) and (09), the corrected value DVa 0 n zero anode voltage is estimated from the measured sum M Σ I cathode currents, setpoint value CI n cathode current and setpoint value CVa 0 n zero anode voltage.

[0057] There figure 3 is a graph representing the evolution of the corrected value DVa 0 n zero anode voltage to be applied depending on the drift ratio Q Σ I, obtained from equations (06) and (08), according to the first and second variant of the invention. As illustrated in the figure 3 , the two variants of the invention are equivalent for a drift ratio Q Σ I very close to 1, and up to 0.6% for an error of ±10% between the measured sum M Σ I cathode currents and the sum Σ n CIK n cathode current setpoints on all 1020-n tubes.

[0058] Advantageously, the determination unit 1046 can be configured to estimate, for each tube 1020-n, the estimated value DG n of persistence, the estimated value THICK n cathode current and / or drift ratio Q Σ I.

[0059] Further, the storage unit 1042 may be configured to store the corrected value DVa 0 n of zero anode voltage, as well as the estimated value DG n of persistence and / or the estimated value THICK n cathode current associated with the 1020-n tube in the calibration table. The storage unit 1042 can also be configured to record the drift ratio Q Σ I.

[0060] Advantageously, the control and power supply module 1040 may comprise an internal clock (not shown in the figures), and the storage unit 1042 may be configured to record and associate with each of the recorded values ​​(estimated value DG n of persistence, estimated value THICK n cathode current, and / or drift ratio Q Σ I ) a timestamp value set by the internal clock. This timestamp value can be set when measuring the sum of the cathode currentsM Σ I in correction mode.

[0061] In some embodiments, the application of the corrected values DVa 0 n zero anode voltage may be performed in response to the detection of a performance drift. For example and without limitation, a performance drift may be determined from the comparison of one or more estimated values THICK n cathode current with a predefined threshold cathode current value. Performance drift can also be determined from the comparison of the corrected values DVa 0 n zero anode voltage with set values CVa 0 n of zero anode voltage, from the comparison of the estimated values DG n of perveance with perveance setpoint values, noted CG n (defined according to equation (01) from the set values CVa 0 n zero anode voltage and setpoint values CI n cathode current) and / or drift ratio comparison Q Σ I with a predefined drift threshold.

[0062] Each 1020-n tube can also be associated with a reference operating point, noted PF n 0 . Each reference operating point PF n 0 of a 1020-n traveling wave tube is associated with a cathode current reference value, noted RIk n , and to a zero anode voltage reference value, denoted RVa 0 n .

[0063] Advantageously, the control and power supply module 1040 can be configured to activate a calibration mode and to perform, during the calibration mode: for a single 1020-n tube to be calibrated, the application of the reference value RVa 0 n zero anode voltage at the 1020-n tube, a first measurement of the sum of the cathode currents M Σ I 1< calibration, for this single 1020-n tube to be calibrated, the application of a given value of zero anode voltage, noted BVa 0 n , a second measurement of the sum of the cathode currents M Σ I 2< calibration, a comparison of the first and second measurements of the sum of the cathode currents M Σ I 1< and M Σ I 2< calibration, and an update of the set value CVa 0 n zero anode voltage from the calibration table from the given value BVa 0 n of zero anode voltage and based on the comparison of the first and second sum measurements.

[0064] In embodiments, the comparison performed during the calibration mode may be further defined from the setpoint value CI ncathode current, of the reference value RIk n of cathode current and a predefined calibration precision setpoint value, noted ε . For example, the comparison performed during the calibration mode can be defined according to the following equation (10): M ∑ Ik 2 − M ∑ Ik 1 − CIk n + RIk n < ε

[0065] Thus, if equation (10) is verified, the set value CVa 0 n zero anode voltage from the calibration table can be replaced by the given value BVa 0 n of zero anode voltage applied to the 1020-n tube. If equality (10) is not verified, another given value BVa 0 n zero anode voltage is chosen and then applied to the 1020-n tube and the calibration mode continues, making a new second measurement of the sum of the cathode currents M Σ I 2< calibration, and a new comparison of the first measurement of the sum of the cathode currents MΣ I 1< calibration with the new second measurement of the sum of the cathode currents M Σ I 2< calibration.

[0066] The choice (i.e., the search) of the given value BVa 0 n zero anode voltage can be performed using successive approximation methods for example.

[0067] According to certain embodiments, the control and power supply module 1040 may be configured to perform, before the calibration mode, a voltage power cut of N-1 tubes and to apply the calibration mode of a single tube 1020-n then powered so as to generate the electron beam 1024 of the tube 1020-n. In this case, the control and power supply module 1040 may be configured to perform, during the calibration mode: for this single 1020-n tube, the application of a given value of zero anode voltage, noted BVa 0 n ,a single measurement of the sum of the cathode currents M Σ I 0< calibration, a comparison of the measured sum M Σ I 0< of the calibration cathode currents with the set value CI n of cathode current, according to the following equality (11): M ∑ Ik 0 = CIk n and an update of the setpoint value CVa 0 n zero anode voltage from the calibration table from the given value BVa 0 n of zero anode voltage and according to the comparison.

[0068] Thus, if equation (11) is verified, the set value CVa 0 n zero anode voltage from the calibration table can be replaced by the given value BVa 0 n of zero anode voltage applied to the 1020-n tube. If equality (11) is not verified, another given value BVa 0 n zero anode voltage is chosen and then applied to the 1020-n tube and the calibration mode continues, making a new single measurement of the sum of the calibration cathode currents M Σ I 0< and a new comparison of the set value CI n cathode current with the new unique measurement of the sum of the calibration cathode currents M Σ I 0< .

[0069] The control and power module 1040 may be configured to repeat the application of the calibration mode at one or more other operating points. PF njof the same 1020-n tube, and / or to another 1020-n tube, to several 1020-n tubes, or to all 1020-n tubes of the system 10. The reiteration of the application of the calibration mode allows a complete or partial update of the calibration table. The control and power supply module 1040 can also be configured to reiterate the application of the calibration mode by performing a power cut of the single 1020-n tube to be calibrated previously controlled and by powering another single 1020-n tube to be calibrated.

[0070] In embodiments, the correction mode and / or the calibration mode may be triggered following the powering of one or more tubes 1020-n, in response to a change in the operating point of a tube and / or in response to the detection of a performance drift. In other embodiments, the correction mode and / or the calibration mode may also be triggered in response to a command from the module 1040 or the external unit 300 of the amplifier device 100. This command to trigger the correction mode and / or the calibration mode may be programmed and / or induced by a ground center.

[0071] Advantageously, in embodiments where the control and power module 1040 comprises an internal clock, the correction mode and / or the calibration mode may be triggered in response to the detection of a predefined timestamp (e.g. via a programmed trigger command), for example periodically. For example and without limitation, the correction mode may be triggered every second while the calibration mode may be triggered every 3 to 6 months, for a number of years from the satellite 10 being placed in orbit, and then every year.

[0072] Thus, the control and power supply module 1040 may comprise a learning unit 1048 configured to calculate, for one or more tubes 1020-n, a trend curve, from the values ​​recorded in the calibration table and the associated time stamp values. The learning unit 1048 may thus be configured to predict (i.e. estimate), from the trend curve, using for example an equation fitted to the trend curve, one or more predicted values ​​of zero anode voltage, noted PVa 0 n , and / or one or more predicted pervasiveness values, noted PG n , for one or more predefined timestamp values.

[0073] In these embodiments, the control and power module 1040 may be configured to determine the detection of a performance drift from the predicted values. PVa 0 n zero anode voltage and / or predicted values PG nof pervasiveness. The control and power module 1040 may also be configured to apply the predicted value(s) PVa 0 n zero anode voltage. This embodiment has the advantage of compensating for the aging of the 1020-n tube by reducing the number of measurements to be carried out (i.e. frequency of correction modes to be activated) and the frequency of calibration modes to be activated.

[0074] In addition, the control and power supply module 1040 comprises one or more specific integrated circuits (not shown in the figures) and / or a digital circuit. For example and without limitation, a digital circuit can be any microcontroller. The different units (and the correction and control modes) can be implemented using one or more of these circuits. In particular, the measurement unit 1044 can be implemented from a single measurement circuit.

[0075] The various embodiments of the invention have the advantage of facilitating the regulation of the operating point of the various traveling wave tubes of the satellite and thus enabling control of the dispersion of the perveance of each of the tubes of the system due to their aging and to temperature variations. The activation and implementation of the calibration mode have the advantage of requiring very little external manual intervention, if any, and of being able to be carried out quickly, over a few hundred milliseconds approximately, with a limited impact on the radiofrequency signal traffic from the satellite 10.

[0076] Furthermore, the various embodiments of the invention have the advantage of reducing the wiring and the number of measuring circuits to a minimum, and thus also reducing its cost.

[0077] There figure 4 and the figure 5are flowcharts describing the method, implemented by a satellite system 10 and in particular by a modular radiofrequency signal amplifier device 100, for controlling the operation and adjustment of the high voltage power supply relative to the traveling wave tubes, according to embodiments of the invention.

[0078] At step 400, the correction mode is activated while each 1020-n tube is used according to an operating point PF n .

[0079] At step 420, for each tube 1020-n, the set value CI n cathode current and the set value CVa 0 n zero anode voltage, associated with the operating point PF n , are received.

[0080] In step 440, in response to the activation of the correction mode, the value of the sum of the cathode currents M Σ Iof the 1020-n tubes is measured by the 1040 control and power supply module.

[0081] Those skilled in the art will easily understand that steps 400, 420 and 440 can be performed simultaneously and / or in a different order, for example a given order defined by module 1040.

[0082] At step 460, for each 1020-n tube, the corrected value DVa 0 n zero anode voltage is determined from the value of the measured sum M Σ I cathode currents, setpoint value CI n cathode current and setpoint value CVa 0 n zero anode voltage.

[0083] At step 480, for each 1020-n tube, the corrected value DVa 0 n zero anode voltage is applied to the 1020-n tube.

[0084] At step 500, calibration mode is activated.

[0085] In step 502, in response to activation of the calibration mode, the reference value RVa 0 n zero anode voltage is applied to a single 1020-n tube to be calibrated.

[0086] At step 504, a first value of the sum of the cathode currents M Σ I 1< calibration is measured.

[0087] At step 506, a given value BVa 0 n zero anode voltage is applied to this single 1020-n tube to be calibrated.

[0088] At step 508, a second value of the sum of the cathode currents M Σ I 2< calibration is measured.

[0089] In step 510, a comparison is made between the calibration precision setpoint ε and a function defined from the second value of the measured sum M Σ I 2< of the calibration cathode currents, of the first value of the measured sum M Σ I1< of the calibration cathode currents, of the set value CI n cathode current and reference value RIk n cathode current.

[0090] In step 512, an update of the calibration table is performed based on the comparison.

[0091] Those skilled in the art will understand that the system and method according to the embodiments of the invention or sub-elements of this system can be implemented in various ways by hardware, software, or a combination of hardware and software, in particular in the form of program code which can be distributed in the form of a program product, in various forms.

[0092] The invention is not limited to the embodiments described above by way of non-limiting example. It encompasses all the variant embodiments that may be envisaged by those skilled in the art. In particular, those skilled in the art will understand that the invention is not limited to the different modules and units of the system and in particular to the different variants of the invention for determining the corrected zero anode voltage value described by way of non-limiting example.

Claims

1. Satellite system (10) comprising an amplifier device (100) for radiofrequency signals, the amplifier device (100) comprising a control and power supply module (1040) and a plurality N of traveling wave tubes (1020-n), the control and power supply module (1040) being configured to apply, for at least one of said tubes (1020-n), a zero anode voltage operating value Va 0 n , the tube (1020-n) generating a cathode current I in response to the application of said zero anode voltage operating value Va 0 n , caractérisé en ce que the control and power supply module (1040) is configured to measure at least a sum of the cathode currents M Σ Iassociated with said plurality N of traveling wave tubes (1020-n), said at least one measurement of the sum of the cathode currents being implemented from a single measurement circuit (1044), the control and power supply module (1040) being further configured to determine at least one corrected operating value of zero anode voltage associated with said at least one of said tubes (1020-n) from said at least one measurement of the sum of the cathode currents.

2. System (10) according to claim 1, wherein each tube (1020-n) is associated with an operating point PF n given associated with a cathode current setpoint value CIk n and at a zero anode voltage setpoint CVa 0 n , the control and power supply module (1040) being configured to apply to each tube (1020-n) said zero anode voltage setpoint value CVa 0 n ,and wherein the control and power supply module (1040) is configured to activate (400) a correction mode and to perform, during said correction mode: - a single measurement of the sum of the cathode currents M Σ I associated with said plurality N of traveling wave tubes (1020-n) at the operating points PF n , - for each tube (1020-n), a determination of a corrected zero anode voltage value DVa 0 n from said single measured sum of cathode currents M Σ I, of said cathode current setpoint value CIk n and said zero anode voltage setpoint value CVa 0 n , the control and power supply module (1040) being further configured to apply, during said correction mode, to each tube (1020-n) said corrected value of the zero anode voltage DVa 0 n associated.

3. System (10) according to claim 2, wherein determining, for each tube (1020-n), said corrected zero anode voltage value DVa 0 n is carried out from an estimated pervasiveness value DG n and said cathode current setpoint value CIk n , said corrected zero anode voltage value DVa 0 n being defined by: DVa 0 n = CIK n DG n + 2 / 3 .

4. System (10) according to claim 2, wherein determining, for each tube (1020-n), said corrected zero anode voltage value DVa 0 n of the traveling wave tube (1020-n) is carried out from a formula of derivative of the cathode current with respect to the zero anode voltage of the tube (1020-n) at the operating point PF n .

5. System (10) according to one of claims 2 to 4, wherein the control and power supply module (1040) is configured to further perform, during said correction mode, a determination of a drift ratio Q Σ I from said single measured sum of cathode currents M Σ I, and a sum of said cathode current setpoint values CIk n of said plurality N of tubes (1020-n).

6. System (10) according to one of claims 2 to 5, wherein the application, during said correction mode, of the corrected value of the zero anode voltage DVa 0 n to the tube (1020-n) is performed in response to a detection of a performance drift of at least one tube of said plurality N of traveling wave tubes (1020-n).

7. System (10) according to claim 6, wherein the control and power module (1040) comprises a data set comprising the operating points PF n recorded, and wherein said performance drift is determined from a comparison of at least one estimated pervasiveness value DG n with a perveance setpoint value CG n included in said data set.

8. System (10) according to claims 5 to 6, wherein the control and power module (1040) comprises a data set comprising the operating points PF n recorded, and wherein said performance drift is determined from a comparison of the drift ratio Q Σ I with a drift threshold included in said data set.

9. System (10) according to one of claims 6 to 8, wherein said performance drift is determined from a comparison, for at least one of said tubes (1020-n), of said corrected value of the zero anode voltage DVa 0 n with said zero anode voltage setpoint CVa 0 n associated.

10. System (10) according to one of claims 2 to 9, in which the control and power module (1040) comprises an internal clock and in which the correction mode is activated in response to a detection of a predefined timestamp.

11. System (10) according to one of claims 2 to 4, in which the control and power supply module (1040) comprises an internal clock and a data set comprising the operating points PF n recorded, the control and power supply module (1040) being configured to record in a calibration table and to associate a timestamp with said corrected value of the zero anode voltage DVa 0 n and / or said estimated value of persistence DG n , and to record, at each activation of the correction mode, said corrected zero anode voltage value DVa 0 n and / or said estimated persistence value DG n in said data set, and wherein the control and power supply module (1040) is further configured to calculate, for at least one tube of said plurality N of traveling wave tubes (1020-n), a trend curve from said data set, and to estimate at least one predicted zero anode voltage value PVa 0 n and / or a predicted value of perveance PG n , associated with a predefined later timestamp value.

12. System (10) according to one of the preceding claims, in which each tube (1020-n) is associated with an operating point PF n given associated with a set zero anode voltage value CVa 0 n and a cathode current setpoint CIk n , and wherein the control and power supply module (1040) is configured to activate (500) a calibration mode and to perform, during said calibration mode: - for a single tube of said plurality N of traveling wave tubes (1020-n), an application of a first zero anode voltage value to the tube (1020-n), - a first measurement of the sum of the cathode currents M Σ I 1 calibration associated with said plurality N of traveling wave tubes (1020-n), - for said single tube (1020-n), an application of a second given value of zero anode voltage BVa 0 n to the tube (1020-n), - a second measurement of the sum of the cathode currents M Σ I 2 calibration associated with said plurality N of traveling wave tubes (1020-n), - a comparison of said first and second measurements of the sum of the cathode currents M Σ I 1 And M Σ I 2 calibration; the control and power supply module (1040) being further configured to perform an update of said setpoint zero anode voltage value CVa 0 n from said second given value of zero anode voltage BVa 0 n and based on said comparison.

13. The system (10) of claim 12, wherein said first zero anode voltage value is a zero anode voltage reference value. RVa 0 n associated with a cathode current reference value RIk n ,and wherein, for said single tube (1020-n), said comparison is further carried out from a calibration precision setpoint ε , of said cathode current setpoint value CIk n and said cathode current reference value RIk n , such that | M Σ I 2 - M Σ I 1 - CIk n + RIk n | < ε.

14. System (10) according to one of claims 12 or 13, in which the calibration mode is activated in response to the detection of a performance drift.

15. A method of controlling and powering a plurality of N traveling wave tubes (1020-n), the method being implemented in a satellite system (10) comprising said traveling wave tubes (1020-n), the method comprising an initial step of applying to at least one of said tubes (1020-n) a zero anode voltage operating value Va 0 n , the tube (1020-n) generating a cathode current I in response to the application of said zero anode voltage operating value Va 0 n , caractérisé en ce que the method comprises the steps of: - measuring (440, 504, 508) at least one sum of the cathode currents associated with said plurality N of traveling wave tubes (1020-n), said at least one measurement of the sum of the cathode currents being implemented from a single measurement circuit (1044), - determining (460, 510-512) at least one corrected operating value of zero anode voltage associated with said at least one of said tubes (1020-n) from said at least one measurement of the sum of the cathode currents.