High-frequency supply of a load without impedance matching
An energy supplying device for a load has a direct current source, a number of switching stages, and a control device. The switching stages are connected to the direct current source, the load, and the control device such that the control device can drive the switching stages to selectively connect the load to the direct current source. Each switching stage has a field effect transistor and a number of freewheeling diodes connected in opposition to the respective field effect transistor in parallel. The field effect transistors have a maximum operational threshold frequency. Each freewheeling diode has a recovery time. For each switching stage, the recovery times of the respective freewheeling diodes correspond with the reciprocal value of the threshold frequency of the respective field effect transistor. The control device controls the switching stages at least intermittently such that power is reflected back into the switching stages on the basis of a mismatch.
1. A power supply device for a load, comprising:
a DC voltage source,
a number of switching stages, and
a control device,
wherein the switching stages are connected to the DC voltage source, the load and the control device, and wherein the control device is configured to selectively drive the respective switching stages to dynamically connect the load to the DC voltage source via one or more of the switching stages selectively driven by the control device,
wherein each of the switching stages has a field effect transistor and a number of freewheeling diodes that are reverse-connected in parallel with the respective field effect transistor,
wherein the field effect transistors have a maximum operational cut-off frequency,
wherein each freewheeling diode is configured with a selected recovery time,
wherein for each of the switching stages, the recovery times of all the freewheeling diodes reverse-connected in parallel with the respective field effect transistor at least approximately correspond to the reciprocal of the cut-off frequency of the respective field effect transistor, and
wherein the control device is configured to drive the switching stages at least at times such that power is reflected back into the switching stages due to a mismatch.
2. The power supply device as claimed in claim 1 , wherein no matching circuit for avoiding the mismatch is arranged between the switching stages and the load.
3. The power supply device of claim 1 , wherein the field effect transistors comprise junction field effect transistors.
4. The power supply device of claim 1 , wherein silicon carbide or gallium nitride is used as semiconductor material for at least one of the field effect transistors and the freewheeling diodes.
5. The power supply device of claim 1 , wherein, for at least one of the switching stages, one of the freewheeling diodes reverse-connected in parallel with the respective field effect transistor is embodied, relative to the respective field effect transistor, as an externally arranged freewheeling diode.
6. The power supply device of claim 1 , wherein, for at least one of the switching stages, one of the freewheeling diodes reverse-connected in parallel with the respective field effect transistor is integrated into the respective field effect transistor.
7. The power supply device of claim 1 , wherein:
the switching stages are at least partly connected in parallel, and
a power combiner is arranged between the parallel-connected switching stages and the load.
8. The power supply device of claim 1 , wherein:
the switching stages are at least partly connected in series in groups of two, and
the groups of two are connected to the load via an outgoing point arranged between the two switching stages of the respective group of two.
9. The power supply device of claim 1 , wherein the switching stages are at least partly combined in pairs to form push-pull amplifiers in the manner of a circlotron.
10. The power supply device of claim 1 , wherein the load is connected to the DC voltage source in a pulsed fashion by the control device via the switching stages.
11. The power supply device of claim 1 , wherein:
the DC voltage source has a rectifier fed from the electrical power supply system, and
a number of buffer capacitors are arranged between the rectifier and the switching stages.
12. The power supply device of claim 1 , wherein the load is embodied as a cavity resonator of a particle accelerator.