A radio frequency (RF) power module combining a high-frequency switching electronic power regulator with vacuum electronic devices ranging from millimeter waves to terahertz.

Abstract

The power module comprises a high-frequency switching electronic power regulator including a plurality of stacked rectifiers / filters, wherein the plurality of stacked rectifiers / filters generate a plurality of stacked DC output voltages, and a vacuum electronic device coupled to the high-frequency switching electronic power regulator, wherein the vacuum electronic device includes a plurality of components, each component receiving a corresponding DC output voltage from the plurality of stacked DC output voltages.

Description

Technical Field

[0001] The present invention generally relates to radio frequency (RF) power modules, and more particularly, provides an RF power module that combines a high-frequency switching electronic power regulator with a vacuum electronic device from millimeter waves to terahertz.

Background Art

[0002] Radio frequency (RF) power modules (such as RF power amplifiers or oscillators) are used as RF generation or amplification stages in RF networks for various applications, including imaging, radar, and communication. Millimeter-wave, sub-terahertz, and terahertz power modules are required to achieve high resolution in imaging and radar systems or high data rates in communication systems.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Radio frequency (RF) power modules (such as RF power amplifiers or oscillators) are used as RF generation or amplification stages in RF networks for various applications, including imaging, radar, communication, and other applications. Millimeter-wave, sub-terahertz, and terahertz power modules are required to achieve high resolution in imaging and radar systems and high data rates in communication systems. High-frequency switching electronic power regulators provide a compact approach to achieving relatively high output voltages. The combination of a high-frequency switching electronic power regulator and a vacuum electronic device from millimeter waves to terahertz enables the implementation of a compact and efficient RF power module.

[0004] Traditionally, achieving both efficiency and power density in electronic power regulators simultaneously has been difficult, particularly for those operating at relatively high voltages (up to 30 kV) with high efficiency (over 85%). Furthermore, when systems operate at lower power levels, such as those achievable by vacuum electronic devices ranging from millimeter waves to terahertz, the achievable power density typically decreases. [Means for solving the problem]

[0005] To achieve high efficiency and compact size in electronic power regulators, high-frequency switching power supply topology can be used. Increasing the frequency switching to levels above 1 MHz increases the power density of lower voltage (<1 kV) power converters. Such a significant increase in frequency allows for a reduction in the importance of passive components within the converter, enabling a substantial reduction in size. In the case of high-voltage electronic power regulators, this is particularly true for magnetic components and output capacitors. Furthermore, as the output voltage increases, the reduction in output capacitance reduces the available stored energy within the electronic power regulator and the resulting power module, enabling safer operation in the event of a system failure. The use of resonant inverter, resonant rectifier, and converter topology reduces switching losses, enabling compact and highly efficient energy conversion.

[0006] To achieve high efficiency in vacuum electronic devices, multi-stage potential reduction collectors can be used. Electromagnetic design of vacuum electronic devices focuses on utilizing various potential interaction mechanisms between the electron beam and simultaneously propagating electromagnetic waves. After the interaction between the electron beam and electromagnetic waves is complete, spent electrons in the electron beam often have a range of energies, meaning they travel at varying speeds. A potential reduction collector matches the electron potential of spent electrons, and as a result, instead of converting the kinetic energy of the electron potential into heat, it "recovers" this kinetic energy and returns it to the power supply. Consequently, only the mismatch between the actual electron energy and electron potential of individual collector electrodes is converted into heat. In particular, potential reduction collectors that convert electron beam energy back into current with efficiency as high as 99% have been demonstrated.

[0007] The number of potential reduction collector stages plays a role in the energy recovery efficiency of the collector. For stacked output designs of high-frequency resonant transducer technology, high-frequency switching electronic power regulators allow easy access to multiple collector voltages at various potentials, enabling optimization of overall system efficiency.

[0008] In some embodiments, the present invention provides a power module comprising a high-frequency switching electronic power regulator including a plurality of stacked rectifiers / filters, wherein the stacked rectifiers / filters generate a plurality of stacked DC output voltages, and a vacuum electronic device coupled to the high-frequency switching electronic power regulator, comprising a plurality of components, each component receiving a corresponding DC output voltage from the plurality of stacked DC output voltages.

[0009] High-frequency switching electronic power regulators may have switching frequencies exceeding 1 MHz. Vacuum electronic devices may operate at frequencies between 28 GHz and 280 GHz. Vacuum electronic devices may operate at frequencies between 280 GHz and 2.8 THz. High-frequency switching electronic power regulators may use resonant topologies. Multiple components may include a set of voltage reduction collector stages, and stacked multiple DC output voltages may include a set of output voltages for the set of voltage reduction collector stages. Multiple components may include a cathode and a cathode heater, and stacked multiple DC output voltages may include a cathode voltage and a cathode heater voltage. The cathode heater voltage may be referenced to the cathode voltage (and may float on the cathode voltage).

[0010] A high-frequency switching electronic power regulator may include a high-frequency inverter, a resonant tank, a transformer coupled to a set of multiple resonant rectifiers / filters stacked with the resonant tank, and a controller configured to control the characteristics of the high-frequency inverter in order to control the DC output voltage according to a specified tolerance. The controller may control the timing of the switching elements of the high-frequency inverter. The transformer may include a primary winding and a set of secondary windings, each secondary winding coupled to a corresponding one of the multiple stacked rectifiers / filters. Multiple components may include a cathode, a cathode heater, and a set of potential reduction collector stages.

[0011] A high-frequency switching electronic power regulator may have two or more sets of power converter stages, each power converter stage may have a high-frequency inverter, a resonant tank, and a transformer coupled to a corresponding one of a plurality of stacked rectifiers / filters with the resonant tank. Each power converter stage may have a controller, which is configured to control the characteristics of the high-frequency inverter in order to control the corresponding DC output voltage of the power converter stage. At least one controller of at least one power converter stage may control the timing of the switching elements of the high-frequency inverter of the power converter stage. The controller may be configured to control the stability of the corresponding DC output voltage to a specified tolerance. A particular power converter stage may be configured to produce at least two DC output voltages, and the controller may be configured to control the stability of at least two DC output voltages to a specified tolerance. The transformer may include a primary winding and a secondary winding, the secondary winding being coupled to a corresponding one of a plurality of stacked rectifiers / filters. A particular power converter stage may have a controller, which is configured to control the characteristics of a high-frequency inverter in order to control the corresponding DC output voltage of the particular power converter stage. The controller may be configured to control the stability of the corresponding DC output voltage to a specified tolerance. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows a power module according to several embodiments of the present invention, which comprises a high-frequency switching electronic power regulator combined with vacuum electronic devices ranging from millimeter waves to terahertz. [Figure 2] This figure shows a high-frequency switching electronic power regulator that provides a single DC output voltage, according to some embodiments of the present invention. [Figure 3A] This figure shows a high-frequency switching electronic power regulator having parallel rectifiers / filters that generate multiple DC output voltages, according to some embodiments of the present invention. [Figure 3B] This figure shows a high-frequency switching electronic power regulator according to several embodiments of the present invention. [Figure 4A] This figure shows a high-frequency switching electronic power regulator having a parallel power converter that generates multiple DC output voltages, according to some embodiments of the present invention. [Figure 4B] This figure shows a high-frequency switching electronic power regulator according to several embodiments of the present invention. [Figure 5] This figure shows a stacked set of multiple rectifiers / filters 408 according to some embodiments of the present invention, where the stacked set of multiple rectifiers / filters 408 stack their respective DC output voltages Vdc to supply power to various components of the vacuum electronic device 104. [Modes for carrying out the invention]

[0013] The following description is provided to enable those skilled in the art to construct and use various embodiments of the present invention. Modifications are possible. The general principles defined herein may be applied to the disclosed embodiments and other embodiments without departing from the scope and spirit of the invention. Accordingly, the claims are not intended to limit to the disclosed embodiments, but should be given the broadest scope consistent with the principles, features and teachings herein.

[0014] Radio frequency (RF) power modules (RF power amplifiers or oscillators, etc.) are used as RF generation or amplification stages in RF networks for a variety of applications, including imaging, radar, and communications. Millimeter-wave, sub-terahertz, and terahertz power modules are required to achieve high resolution in imaging and radar systems, and high data rates in communications systems. High-frequency switching electronic power regulators offer a compact approach to achieving relatively high output voltages. The combination of high-frequency switching electronic power regulators and vacuum electronic devices ranging from millimeter-wave to terahertz enables the implementation of compact and efficient RF power modules.

[0015] Traditionally, achieving both efficiency and power density in electronic power regulators simultaneously has been difficult, particularly in electronic power regulators operating at relatively high voltages (up to 30 kV) with high efficiency (over 85%). Furthermore, when systems operate at lower power levels, such as those achievable by vacuum electronic devices ranging from millimeter waves to terahertz, the achievable power density typically decreases.

[0016] To achieve high efficiency and compact size in electronic power regulators, high-frequency switching power supply topology can be used. Increasing the frequency switching to levels above 1 MHz increases the power density of lower voltage (<1 kV) power converters. Such a significant increase in frequency allows for a reduction in the importance of passive components within the power supply, enabling a substantial reduction in size. In the case of high-voltage electronic power regulators, this is particularly true for magnetic components and output capacitors. Furthermore, as the output voltage increases, the output capacitance decreases, reducing the available stored energy within the electronic power regulator and the resulting power module, enabling safer operation in the event of system failure. The use of resonant inverter, resonant rectifier, and converter topology reduces switching losses, enabling compact and highly efficient energy conversion.

[0017] To achieve high efficiency in vacuum electronic devices, multi-stage potential reduction collectors can be used. The electromagnetic design of vacuum electronic devices focuses on utilizing various potential interaction mechanisms between the electron beam and electromagnetic waves propagating simultaneously. After the interaction between the electron beam and electromagnetic waves is complete, spent electrons in the electron beam often have a range of energies, meaning that spent electrons travel at varying speeds. Potential reduction collectors match the electron potential of spent electrons, and as a result, instead of converting the kinetic energy of the electron potential into heat, this kinetic energy is "recovered" and returned to the power supply. Consequently, only the mismatch between the actual electron energy and electron potential of the individual collector electrodes is converted into heat. In particular, potential reduction collectors that convert electron beam energy back into current with an efficiency of as high as 99% have been demonstrated.

[0018] The number of potential reduction collector stages plays a role in the energy recovery efficiency of the collector. For stacked output designs of high-frequency resonant transducer technology, high-frequency switching electronic power regulators allow easy access to multiple collector voltages at various potentials, enabling optimization of overall system efficiency.

[0019] Figure 1 shows an RF power module 100 according to several embodiments of the present invention. The RF power module 100 comprises a high-frequency switching electronic power regulator 102, which is combined with a vacuum electronic device 104 (for example, an RF power amplifier or oscillator such as a klystron or traveling wave tube (TWT)) ranging from millimeter waves to terahertz. The vacuum electronic device 104 may operate at frequencies between 28 GHz and 280 GHz or between 280 GHz and 2.8 THz.

[0020] As shown in the figure, the vacuum electronic device 104 includes an electron gun 106, the electron gun 106 is coupled to an interaction structure 112, and the interaction structure 112 is coupled to a potential reduction collector 114. The electron gun 106 may include a cathode 108 and a cathode heater 110. When the vacuum electronic device 104 is a power amplifier, the interaction structure 112 may have an RF input (RF-In) and an RF output (RF-Out). When the vacuum electronic device 104 is an oscillator, the interaction structure 112 may have only an RF output (RF-Out). The potential reduction collector 114 may have any number (N) of collector stages, for example, four collector stages 114a-114d as shown in the figure.

[0021] Regarding voltage, in some embodiments, the electron gun 106 may receive two different voltages, namely, the voltage at the cathode potential and the voltage at the cathode potential offset by the heater voltage (the offset voltage of the heater). The cathode 108 may receive the cathode voltage. The cathode heater 110 may receive a voltage generated from the cathode voltage and the offset voltage of the heater. In some embodiments, the cathode heater 110 is a floating voltage with respect to the cathode 108. In some embodiments, there are additional electrodes within the electron gun, and the voltage generated by the high-efficiency switching electronic power regulator 102 is applied to each electrode. The body of the interaction structure 112 is maintained at a ground potential. Each collector stage 114a-114d of the potential reduction collector 114 may operate at a different collector voltage based on the electron potential of the used electrons designed to be captured by the collector stages 114a-114d, and thus the energy range designed to be recovered by the collector stages 114a-114d. Therefore, the potential reduction collector 114 may receive N different voltage potentials. The high-frequency switching electronic power regulator 102 is configured to generate the voltages required by the vacuum electronic device 104, including the cathode voltage, the offset voltage of the heater, the ground, and the N collector voltages. In some embodiments, the high-frequency switching electronic power regulator 102 has a stacked configuration such that the DC output voltages are built on top of each other.

[0022] In some embodiments, the cathode 108 is heated by a resistance heater 110. To heat the cathode 108, a cathode voltage is applied to the electrode. Since the heater 110 is close to or electrically connected to the cathode 108, the heater voltage can be configured to "float" on top of the cathode voltage. Thus, when the cathode voltage is at ground (i.e., the high cathode voltage is not energized), the heater current is also close to ground. When the cathode voltage is at its operating voltage, the heater voltage is close to or referenced to the operating voltage of the cathode. In such embodiments, the small voltage for the heater, which may be only a few volts, remains close to the cathode voltage that can vary from a few kilovolts to tens of kilovolts from ground. In some embodiments, this is achieved by having a high-frequency switching electronic power regulator 102 that implements a heater voltage referenced to the cathode voltage (floating on top of the cathode voltage).

[0023] In the case of a communication system, it is extremely important for the output signal of the RF power amplifier to faithfully reproduce the input signal with only a slight increase in amplitude. If the voltage applied to the electrodes within the vacuum electronic device 104 is not sufficiently stable / constant, the amplitude and / or phase of the output signal may shift due to voltage fluctuations. The amplitude shift due to voltage fluctuations is called the amplitude pushing coefficient. The phase shift due to voltage fluctuations is called the phase pushing coefficient. The vacuum electronic device 104 has pushing coefficient requirements associated with the voltage received by the vacuum electronic device 104. In addition to the amplitude and phase distortion of the RF output signal, voltage fluctuations can also cause other undesirable effects. For example, when the potential-reduced collector voltage drifts extremely, used electrons may rotate due to electrostatic repulsive forces. The used electrons may reverse and unnecessarily heat the circuit or the gun, reducing efficiency.

[0024] In light of the problems caused by voltage fluctuations, the high-frequency switching electronic power regulator 102 must be configured to maintain the voltage it provides sufficiently stably within the performance requirements of the vacuum electronic device 104. In particular, strictly regulating all voltages to the same tolerance may not be practical, as this may result in large and / or expensive hardware. Therefore, in some embodiments, the high-frequency switching electronic power regulator 102 may stably maintain each or a subset of its DC output voltages according to various tolerances. In other embodiments, the high-frequency switching electronic power regulator 102 may stably maintain some or all of its DC output voltages according to several tolerances. The high-frequency switching electronic power regulator 102 may be designed, based on the circuit design space, to include individual regulation of each DC output voltage within a specified tolerance range, or mutual regulation of some or all of the DC output voltages within a specified tolerance range.

[0025] In some embodiments, the high-frequency switching electronic power regulator 102 may satisfy some or all of the characteristics shown in the following table in order to effectively supply power to the vacuum electronic device 104.

[0026] TIFF2026517147000002.tif125170

[0027] In some embodiments, the vacuum power device 104, such as a traveling wave tube, may have the following requirements in order to achieve the full performance of the RF power amplifier.

[0028] TIFF2026517147000003.tif125170

[0029] To achieve the desired performance characteristics of the RF power module 100, in some embodiments, the high-frequency switching electronic power regulator 102 and the vacuum electronic device 104 can be designed simultaneously. Therefore, the specifications of the lower-level components can be developed to ensure that each component meets its individual specifications. Knowledge of the performance requirements and associated voltage sensitivity of the vacuum electronic device 104 allows for the development of a high-frequency switching electronic power regulator 102 that meets these requirements. Developing the high-frequency switching electronic power regulator 102 and the vacuum electronic device 104 together simultaneously enables the optimization of the entire power module 100 as a complete system, providing a design that takes into account the respective design spaces and ensures that both components work together.

[0030] Figure 2 shows a high-frequency switching electronic power regulator 200 that provides a single DC output voltage according to several embodiments of the present invention. In some embodiments, the high-frequency switching electronic power regulator 200 may be implemented using a high-frequency switching resonant converter topology to achieve high efficiency and power density. The high-frequency switching electronic power regulator 102 may operate similarly to the high-frequency switching electronic power regulator 200, but with a duplicated stage for generating multiple DC output voltages. See Figures 3A and 3B as an example, and Figures 4A and 4B as another example.

[0031] In some embodiments, the high-frequency switching electronic power regulator 200 includes a high-frequency inverter 202, which is coupled to a resonant tank 204, which is coupled to a transformer 206, which is coupled to a resonant rectifier / filter 208. Operating at a high frequency (e.g., >1 MHz), the inverter 202 receives a DC input voltage and, together with the resonant tank 204, transforms the voltage and / or current waveform to change sinusoidally during one or more subsections of each switching period. The sinusoidally changing waveform allows the switching of active components, switches and rectifiers in the circuit to occur with minimal energy loss during each switching transient. The transformer 206 receives a modified AC square wave from the resonant tank 204 and transforms the voltage of the modified AC square wave based on the number from primary to secondary windings. The resonant rectifier / filter 208 receives a voltage-modified AC wave, rectifies and filters it, and generates a DC output voltage that supplies power to its load. As described above, various sections of the circuit can be duplicated (e.g., stacked) to generate multiple DC output voltages.

[0032] The high-frequency switching electronic power regulator 200 may further include a controller 210 which optionally compares the DC output voltage to a reference voltage or reference voltage range, controls the high-frequency inverter 202, adjusts the frequency and / or duty cycle of the high-frequency inverter 202, and adjusts the DC output voltage as needed. In some embodiments, the controller 210 may be a pulse-width modulation (PWM) controller that controls the duty cycle of the high-frequency inverter 202 to affect the DC output voltage as needed, or may include a pulse-width modulation (PWM) controller. The controller 210 may regulate the DC output voltage to be kept strictly within a specified tolerance. For example, a reference voltage range (e.g., arbitrary hysteresis) may be kept strictly based on a specified tolerance.

[0033] By increasing the frequency of the high-frequency inverter 202 to a frequency exceeding 1 MHz, the size of the transformer 206, as well as the passive components including the inductors and capacitors in the resonant tank 204 and resonant rectifier / filter 208, is effectively reduced, thereby enabling a reduction in the size of the high-frequency switching electronic power regulator 200.

[0034] Figure 3A shows a parallel, possibly stacked, resonant rectifier / filter generating multiple DC output voltages according to several embodiments of the present invention. The high-frequency switching electronic power regulator 300 may be an example of the high-frequency switching electronic power regulator 102. The high-frequency switching electronic power regulator 300 is similar to the high-frequency switching electronic power regulator 200, except that the transformer 302 includes multiple (m) parallel secondary windings, each secondary winding coupled to a parallel rectifier / filter 304 that generates a corresponding DC output voltage. Each parallel rectifier / filter 304 receives a voltage-corrected AC wave arriving from its parallel secondary winding, rectifies and filters it, and generates the DC output voltage required by the vacuum electronic device 104. That is, each parallel resonant rectifier / filter 304 may generate a cathode voltage, a heater offset voltage, and one of N collector voltages. In some embodiments, the cathode voltage and the heater offset voltage may be generated by the same resonant rectifier / filter 304. In some embodiments, the number of secondary windings in each secondary winding may vary based on the desired DC output voltage. In some embodiments, the circuit components in the parallel resonant rectifier / filter 304 may vary based on the desired DC output voltage. In some embodiments, both the number of secondary windings in each secondary winding and the circuit components in the parallel resonant rectifier / filter 304 may vary.

[0035] The high-frequency switching electronic power regulator 300 may further include a controller 306 which compares at least one DC output voltage of the parallel rectifier / filter 304 to a possible reference voltage or reference voltage range, controls the high-frequency inverter 202, adjusts the inverter characteristics, e.g., frequency, phase and / or duty cycle of the high-frequency inverter 202, and adjusts the DC output voltage as needed. In some embodiments, the controller 306 may be a pulse-width modulation (PWM) controller that controls the duty cycle of the high-frequency inverter 202 to affect the DC output voltage as needed, or may include a pulse-width modulation (PWM) controller. The controller 210 may regulate the DC output voltage to be kept strictly within a specified tolerance. For example, the reference voltage range (e.g., any hysteresis) may be kept more strictly based on the specified tolerance. In some embodiments, the specified tolerance may be the tightest tolerance required by the most sensitive voltage of the vacuum electronic device 104.

[0036] Figure 3B shows a high-frequency switching electronic power regulator 300 according to several embodiments of the present invention. The high-frequency switching electronic power regulator 300 includes a high-frequency inverter 202 coupled to a resonant tank 204, the resonant tank 204 is coupled to a transformer 302, and the transformer 206 is coupled to a parallel resonant rectifier / filter 304. The transformer 302 includes a primary winding 352 (which may or may not have a center tap configuration), and the primary winding 352 is coupled via a core 356 to secondary windings 354(1) to 354(m) (each collectively referred to as secondary winding 354) (each collectively referred to as secondary winding 354) (each collectively referred to as secondary winding 354) (each collectively referred to as secondary winding 354) (each collectively referred to as resonant rectifier / filter 304). Each resonant rectifier / filter 304(1) to 304(m) generates a DC output voltage Vdc1 to Vdcm, respectively.

[0037] As similarly described with respect to Figure 2, the inverter 202, operating at a high frequency (e.g., >1 MHz), receives a DC input voltage and, together with the resonant tank 204, transforms the voltage and / or current waveform to change sinusoidally during one or more sub-sections of each switching period. The sinusoidally changing waveform allows the switching of active components, switches and rectifiers in the circuit to occur with minimal energy loss during each switching transient. The transformer 206 receives the modified AC square wave from the resonant tank 204 and transforms the voltage of the modified AC square wave based on the number of windings from the primary winding to the secondary winding 354. Each resonant rectifier / filter 304 receives the voltage-modified AC wave, rectifies and filters it, and generates a DC output voltage that supplies power to each load, respectively. As described above, the number of windings in each secondary winding may vary based on the desired DC output voltage. In some embodiments, the circuit components in the parallel resonant rectifier / filter 304 may vary based on the desired DC output voltage. In some embodiments, both the number of secondary windings in each secondary winding and the circuit components in the parallel resonant rectifier / filter 304 may differ.

[0038] As described above, the high-frequency switching electronic power regulator 300 may further include a controller 306 which compares at least one DC output voltage of a resonant rectifier / filter 304, e.g., a resonant rectifier / filter 304(m), to a possible reference voltage or reference voltage range, controls the high-frequency inverter 202, adjusts the inverter characteristics, e.g., the frequency, phase, and / or duty cycle of the high-frequency inverter 202, and adjusts the DC output voltage as needed. In some embodiments, the controller 306 may be a pulse-width modulation (PWM) controller that controls the duty cycle of the high-frequency inverter 202 to affect the DC output voltage as needed, or may include a pulse-width modulation (PWM) controller. The controller 210 may regulate the DC output voltage to be kept strictly within a specified tolerance. For example, a reference voltage range (e.g., any hysteresis) may be kept strictly based on a specified tolerance. In some embodiments, the specified tolerance may be the tightest tolerance required by the most sensitive voltage requirements of the vacuum electronic device 104.

[0039] Figure 4A shows a high-frequency switching electronic power regulator 400 having parallel power converter stages that generate multiple DC output voltages, according to some embodiments of the present invention. In some embodiments, the high-frequency switching electronic power regulator 400 includes a set of parallel high-frequency inverters 402 coupled to a set of parallel resonant tanks 404, the set of parallel resonant tanks 404 coupled to a set of parallel transformers 406, and the set of parallel transformers 406 coupled to a set of parallel rectifiers / filters 408. In other words, the high-frequency switching electronic power regulator 400 includes several parallel power converter stages, each power converter stage includes each parallel high-frequency inverter 402, each parallel high-frequency inverter 402 is coupled to each resonant tank 404, each resonant tank 404 is coupled to each transformer 406, and each transformer 206 is coupled to each resonant rectifier / filter 408. Each power converter stage generates a DC output voltage (or possibly a subset of DC output voltages) that can be regulated according to various tolerance levels. In some embodiments, some or all sets of parallel resonant rectifiers / filters 408 may be stacked to establish an increasing DC output voltage relative to one another within the set.

[0040] In some embodiments, a set of high-frequency inverters 402 receive a DC input voltage. Each inverter 402, operating at a high frequency (e.g., >1 MHz), receives the DC input voltage and, together with the resonant tank 204, transforms the voltage and / or current waveform to change sinusoidally during one or more subsections of each switching period. The sinusoidally changing waveform allows the switching of active components, switches and rectifiers in the circuit to occur with minimal energy loss during each switching transient. Each transformer 406 receives a modified AC square wave from the associated resonant tank 404 and transforms the voltage of the modified AC square wave based on the number from primary to secondary windings. Each resonant rectifier / filter 408 receives the voltage-modified AC wave, rectifies and filters it, and generates a DC output voltage that supplies power to each load, respectively. In some embodiments, each resonant rectifier / filter 408 may be stacked such that the DC output voltage increases relative to the floating DC output voltage of the preceding resonant rectifier / filter 408, upon which the next resonant rectifier / filter 408 is stacked.

[0041] The high-frequency switching electronic power regulator 400 may further include a set of parallel controllers 410. In other words, each parallel converter stage may have each controller 410, each controller 410 which, optionally, compares each DC output voltage to each reference voltage or reference voltage range, controls each high-frequency inverter 402, adjusts the characteristics of the inverter, e.g., the frequency, phase and / or duty cycle of the high-frequency inverter 402, and adjusts the corresponding DC output voltage as needed. In some embodiments, one or more of the controllers 410 may be pulse-width modulation (PWM) controllers that control the duty cycle of the high-frequency inverter 402 to affect the DC output voltage as needed, or may include pulse-width modulation (PWM) controllers. By using separate controllers 410 within each converter stage, the DC output voltage can be maintained sufficiently stably according to different tolerance standards. In some embodiments, in particular, if the resonant rectifier / filter 408 is stacked, and the resonant rectifier / filter 408 is stable and the specified tolerance requirements are matched across the entire DC output voltage, only a single controller 410 is required.

[0042] Figure 4B shows a high-frequency switching electronic power regulator 400 having parallel power converter stages 460(1) to 460(m) (collectively referred to herein as power converter stage 460) that generate a plurality of DC output voltages, according to several embodiments of the present invention. The high-frequency switching electronic power regulator 400 comprises several parallel power converter stages 460(1) to 460(m), each power converter stage 460 comprising a high-frequency inverter 402, each high-frequency inverter 402 coupled to each resonant tank 404, each resonant tank 404 coupled to each transformer 406, and each transformer 406 coupled to each resonant rectifier / filter 408. As shown in the figure, the first power converter stage 460(1) includes a first high-frequency inverter 402(1), the first high-frequency inverter 402(1) is coupled to a first resonant tank 404(1), the first resonant tank 404(1) is coupled to a first primary winding 452(1), the first primary winding 452(1) is coupled to a first secondary winding 454(1) of the first converter 406 via a first core 456(1), and the first secondary winding 454(1) is coupled to a first resonant rectifier / filter 408(1). As shown in the figure, the mth power converter stage 460(m) includes the mth high-frequency inverter 402(m), the mth high-frequency inverter 402(m) is coupled to the mth resonant tank 404(m), the mth resonant tank 404(m) is coupled to the mth primary winding 452(m), the mth primary winding 452(m) is coupled to the mth secondary winding 454(m) of the mth converter 406 via the mth core 456(m), and the mth secondary winding 454(m) is coupled to the mth resonant rectifier / filter 408(m). Each power converter stage generates its own DC output voltage (or possibly a subset of DC output voltages). In some embodiments, some or all sets of resonant rectifiers / filters 408 can be stacked to establish DC output voltages that increase relative to each other within the set.

[0043] In some embodiments, each high-frequency inverter 402(1) to 402(m) receives a DC input voltage. Each inverter 402(1) to (m), operating at a high frequency (e.g., >1 MHz), receives the DC input voltage and, together with the resonant tanks 404(1) to (m), transforms the voltage and / or current waveform to change sinusoidally during one or more subsections of each switching period. The sinusoidally changing waveform allows the switching of active components, switches and rectifiers in the circuit to occur with minimal energy loss during each switching transient. Each transformer 406 receives the modified AC square wave from each associated resonant tank 404(1) to (m), respectively, and transforms the voltage of the modified AC square wave based on the number of primary to secondary windings in each primary winding 452(1) to (m) and secondary winding 454(1) to (m). Each resonant rectifier / filter 408(1)~(m) receives a voltage-corrected AC wave, rectifies and filters it, and generates a DC output voltage that supplies power to each load, respectively. In some embodiments, the resonant rectifiers / filters 408(1)~(m) can be stacked to establish a DC output voltage that increases relative to the floating DC output voltage of the preceding resonant rectifier / filter 408(1)~(m), with the next resonant rectifier / filter 408(1)~(m) being stacked on top of each other.

[0044] One, some, or all of the power converter stages 460(1) to (m) of the high-frequency switching electronic power regulator 400 may have controllers, each controller optionally comparing each DC output voltage to each reference voltage or reference voltage range, each controller controlling each high-frequency inverter 402(1) to (m), adjusting the inverter characteristics, e.g., the frequency, phase, and / or duty cycle of the high-frequency inverter 402(1) to (m), and adjusting each DC output voltage as needed. In some embodiments, one or more controllers 410(1) to (m) may be pulse-width modulation (PWM) controllers that control the duty cycle of the corresponding high-frequency inverter 402(1) to (m) as needed, or may include pulse-width modulation (PWM) controllers. By using separate controllers 410(1) to (m) within each power converter stage 460, each DC output voltage can be maintained sufficiently stably according to different tolerance standards. In some embodiments, in particular, when the resonant rectifiers / filters 408(1)~(m) are stacked, and the resonant rectifiers / filters 408(1)~(m) are stable and the specified tolerance requirements are consistent across the entire DC output voltage, only a single controller 410 is required.

[0045] It will be understood that some embodiments may include a parallel power converter stage shown in Figure 4B, which is combined with a parallel resonant rectifier / filter 304 shown in Figure 3B.

[0046] The use of high-frequency switching enables smaller module power converter stages, or modules that can be configured both in series and parallel, to achieve the design voltage and design power handling capability. This allows for module designs that can accommodate various power amplifier requirements regarding operating voltage, number of collector stages, and total power level. The module approach allows for rapid adaptation to designs that improve the operation of the power amplifier. Stages can be used in parallel and scaled up or down to achieve the required power amplifier performance described above. If the vacuum electronic device 104 is found to operate better in a different configuration than the one initially designed, or in various configurations for different use cases, the high-frequency switching electronic power regulator 102 can be quickly reconfigured. Stages can be physical modules fabricated as individual PCB assemblies, or they can be “patterns” used during the design phase and then fabricated as components of larger PCB assemblies.

[0047] Figure 5 shows a stacked set of rectifiers / filters 408 according to several embodiments of the present invention, where the stacked set of rectifiers / filters 408 stack their respective DC output voltages Vdc to supply power to various components of the vacuum electronic device 104. The stacked set of rectifiers / filters 408 may be part of a high-frequency switching electronic power regulator 300 or a switching electronic power regulator 400. More specifically, a first rectifier / filter 408(1) may generate a ground potential for the interacting structure 112 and a first DC output voltage Vdc(1) to supply power to the first collector stage 114(a). A second rectifier / filter 408(2) may generate a second DC output voltage Vdc(2) floating on the first DC output voltage Vdc(1) to supply power to the second collector stage 114(b). A third rectifier / filter 408(3) can generate a third DC output voltage Vdc(3) floating on the second DC output voltage Vdc(2) to supply power to the third collector stage 114(c). A fourth rectifier / filter 408(4) can generate a fourth DC output voltage Vdc(4) floating on the third DC output voltage Vdc(3) to supply power to the fourth collector stage 114(d). A fifth rectifier / filter 408(5) can generate a fifth DC output voltage Vdc(m) floating on the fourth DC output voltage Vdc(4) to supply power to the cathode 108. A sixth rectifier / filter 408(6) can generate a sixth DC output voltage Vdc(6) floating on the fifth DC output voltage Vdc(5) to supply power to the cathode heater 110. Other embodiments are possible. For example, in some embodiments, there may be fewer or more collector stages. In some embodiments, a single rectifier / filter 408 may generate multiple voltages to supply power to multiple components of the vacuum electronic device 104.

[0048] In some embodiments, cathode regulation needs to be high voltage and quite strict (low ripple and constant DC) to achieve low unwanted distortion of the RF signal. The primary current is the current flowing from the cathode (not to the collector) to ground. The primary current is affected by the RF input signal and is therefore a variable that loads the cathode voltage generation system. To prevent backflow at the collector, the stability of the collector electrode voltage must be maintained in the presence of a dynamically changing load (i.e., the current flowing through the collector stage is determined by the applied RF signal). Operating conditions under which the RF output does not pass through fully saturated RF output operation vary significantly with respect to the collector. This means that the power supply unit experiences a fluctuating load on each electrode. Since this fluctuation can occur at the RF frequency, the load can change rapidly. The power supply unit design must be appropriate to maintain regulation in the presence of these rapidly changing loads.

[0049] The design of the high-frequency switching electronic power regulator 102 is influenced by the design of the vacuum electronic device 104, and therefore the vacuum electronic device 104 affects the efficiency and overall original power. Since efficiency and size are influenced by the quality of the design, ensuring that only the necessary design details are implemented will help in a quick design cycle. Three-way optimization can be implemented in terms of size, power (efficiency), and performance.

[0050] As electrons leave the cathode, they carry thermal energy with them, cooling the cathode. The performance of the cathode depends on temperature control in terms of its ability to generate the required current. Since the vacuum electronic device 104 operates at higher duty cycles up to CW, increasing the heater power requires maintaining the cathode at a design temperature that supplies the required cathode current. The power module may incorporate various approaches to maintain this temperature. In one embodiment, a lookup table or analog circuit is used to adjust the heater power based on the duty cycle in which the unit operates. In another embodiment, the cathode current is detected and a feedback loop is used to control the heater power and maintain the emitted cathode current within a desired range.

[0051] Noise power is a critical characteristic of RF power amplifiers because it imposes a limit on the achievable signal-to-noise ratio and, therefore, limits the total data rate that can be achieved in a communication system. One measure of this noise power is the error vector amplitude, characterized by the error in the constellation plot as the communication system processes the waveform. RF noise is affected by electronic noise on the cathode voltage and noise within the vacuum electronic device 104 (particularly shot noise). Achieving the required RF performance requires harmonizing the noise tolerated in the vacuum electronic device 104.

[0052] In the case of a power amplifier using a configuration without control electrodes within the gun, the amplifier does not need to have a module to switch the beam on and off. A beam-on / off module is otherwise common in typical vacuum electronic device power supplies. This makes the overall system smaller (no modulated anode or beam tuner / grid / aperture grid required). In such amplifiers, the vacuum electronic device 104 and the high-frequency switching electronic power tuner 102 must operate through non-nominal conditions, particularly during on and off transitions. Because low cathode voltages may result in insufficient beam transmission from the vacuum electronic device 104, the system passes through periods of high primary current during on and off transients. This can cause damage to the vacuum electronic device 104, or damage to the high-voltage switching electronic power tuner 102, or cause the high-voltage switching electronic power tuner 102 to self-protect by entering a failure state. Each of these consequences is undesirable for the system to be manageable. The designer must ensure that the combination of the rise and fall times of the output voltage of the high-voltage switching electronic power regulator 102, along with the thermal robustness of the vacuum electronic device 104, can withstand transient conditions between on and off. The designer must also ensure that the protection circuit of the high-voltage switching electronic power regulator 102 is configured to allow the unit to "survive" an on transient power surge if the unit exceeds its protection limits in a short period of time.

[0053] The high-frequency switching electronic power regulator 102 must be able to withstand arcs from any electrode to any electrode or from any electrode to ground within the vacuum electronic device 104. Furthermore, the high-frequency switching electronic power regulator 102 must ensure that the vacuum electronic device 104 is not damaged by arc events. In some configurations, the high-frequency switching electronic power regulator 102 may be accompanied by a fast protection circuit designed to remove voltage when an arc is detected. In other embodiments, the high-frequency switching electronic power regulator 102 may be involved in selecting the amount of stored energy available to supply the arc, and, in addition to a slower protection circuit, in controlling where and how the stored energy is dissipated within the complete arc path.

[0054] Throughout this specification, multiple examples may implement components, actions, or structures described as single examples. Individual actions of one or more methods are shown and described as separate actions, but one or more of these actions may be performed simultaneously and do not need to be performed in the order in which they are shown. Structures and functions presented as individual components in exemplary configurations may be implemented as structures or combinations of components. Similarly, structures and functions presented as single components may be implemented as individual components. These and other variations, modifications, additions, and improvements are within the scope of the subject matter of this specification.

[0055] The above description of preferred embodiments of the present invention is merely illustrative, and other variations and modifications of the embodiments and methods are possible in light of the above teachings. The embodiments described herein are not intended to be exhaustive or limiting. The present invention is limited only by the following claims.

Claims

1. It is a power module, A high-frequency switching electronic power regulator comprising a plurality of stacked resonant rectifiers / filters, wherein the plurality of stacked resonant rectifiers / filters generate a plurality of stacked DC output voltages, A vacuum electronic device coupled to the aforementioned high-frequency switching electronic power regulator, comprising a plurality of components, each component receiving a corresponding DC output voltage from the plurality of stacked DC output voltages, A power module equipped with the following features.

2. The power module according to claim 1, wherein the high-frequency switching electronic power regulator has a switching frequency exceeding 1 MHz.

3. The power module according to claim 1, wherein the vacuum electronic device operates at a frequency between 28 GHz and 280 GHz.

4. The power module according to claim 1, wherein the vacuum electronic device operates at a frequency between 280 GHz and 2.8 THz.

5. The power module according to claim 1, wherein the high-frequency switching electronic power regulator uses a resonant topology.

6. The power module according to claim 1, wherein the plurality of components include a set of voltage reduction collector stages, and the stacked plurality of DC output voltages include a set of DC output voltages for the set of voltage reduction collector stages.

7. The power module according to claim 1, wherein the plurality of components include a cathode and a cathode heater, and the stacked plurality of DC output voltages include a cathode voltage and a cathode heater voltage.

8. The power module according to claim 1, wherein the cathode heater voltage is referenced to the cathode voltage.

9. The aforementioned high-frequency switching electronic power regulator is High-frequency inverter and A resonant tank and A transformer coupled to the resonant tank and the stacked set of multiple resonant rectifiers / filters, A controller configured to control the characteristics of the high-frequency inverter in order to control the DC output voltage according to a specified tolerance, The power module according to claim 1, including the following:

10. The power module according to claim 9, wherein the controller includes pulse width modulation for controlling the duty cycle of the high-frequency inverter.

11. The power module according to claim 9, wherein the transformer includes a primary winding and a set of secondary windings, each secondary winding being coupled to a corresponding one of the stacked plurality of rectifiers / filters.

12. The power module according to claim 1, wherein the plurality of components include a cathode, a cathode heater, and a set of potential reduction collector stages.

13. The aforementioned high-frequency switching electronic power regulator has a set of two or more power converter stages, Each power converter stage is: High-frequency inverter and A resonant tank and The resonant tank and a transformer coupled to a corresponding one of the stacked resonant rectifiers / filters include The power module according to claim 1.

14. The power module according to claim 13, wherein each power converter stage has a controller, the controller is configured to control the characteristics of the high-frequency inverter in order to control the corresponding DC output voltage of the power converter stage.

15. The power module according to claim 14, wherein at least one controller of at least one of the power converter stages includes pulse width modulation for controlling the duty cycle of the high-frequency inverter of the power converter stage.

16. The power module according to claim 13, wherein the controller is configured to control the stability of the corresponding DC output voltage to a specified tolerance.

17. The power module according to claim 13, wherein a specific power converter stage is configured to generate at least two DC output voltages, and the controller is configured to control the stability of the at least two DC output voltages to a specified tolerance.

18. The power module according to claim 13, wherein the transformer includes a primary winding and a secondary winding, the secondary winding being coupled to a corresponding one of the stacked plurality of resonant rectifiers / filters.

19. The power module according to claim 13, wherein a particular power converter stage has a controller, the controller is configured to control the characteristics of the high-frequency inverter in order to control the corresponding DC output voltage of the particular power converter stage.

20. The power module according to claim 19, wherein the controller is configured to control the stability of the corresponding DC output voltage to a specified tolerance.

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