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US 2003/0151459 A1Published application
High frequency switch-mode power amplifier
AssigneeLing Dynamic Systems Ltd.
InventorRobert Leedham
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AssigneeLing Dynamic Systems Ltd.
InventorRobert Leedham
Estimating the term…
A switch-mode power amplifier circuit using high power, low distortion waveforms is connected to an electromagnetic load to provide a high degree of control over the load. The circuit comprising a plurality of half-bridge networks having outputs combined at a summation point. The half-bridge networks are switched to provide power outputs sequenced to generate an interlaced output at the summation point which is operably connected to the load so that for a given switching frequency of the networks the operational frequency of the circuit is increased. The sequencing of the half-bridge outputs to generate an interlaced output facilitates the reduction of the switching frequency of individual switching components within the half-bridges while at least maintaining the overall operational frequency of the circuit. For N half-bridges operating at fkHz, the overall operational frequency of the circuit is NfkHz. Alternatively, the switching frequency of individual switching elements of a system operating at fokHz may be reduced by a factor of N. A feedback signal generated across the load is included at the summation point and is optionally augmented to decrease distortion.
A switch-mode power amplifier circuit connectable to an electromagnetic load, the circuit comprising a plurality of half-bridge networks having outputs combined for summation at a summation point, the half-bridge networks being switched to provide power outputs sequenced to generate an interlaced output at the summation point which is operably connected to a load so that for a given switching frequency of the networks the operational frequency of the circuit is increased.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which a feedback path is provided so that a feedback signal is generated across a load.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims. in which the half-bridge networks are arranged in a push-pull configuration about a load, the configuration defining a left and right channel for which a power drive signal may be derived to generate timing signals for controlling individual switching elements of the half-bridge networks.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which a timing strategy is used to ensure current sharing between the networks.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which each half-bridge network comprises two switching components in opposite switched states.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which an identical supply voltage is supplied to each half-bridge network.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which the switched power outputs of the half-bridge networks are provided with an in-line inductance.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which an output filter stage is provided on the circuit, at least part of which is shunt-connected across a load in use.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which a current sensor is provided on the output of each half-bridge network so that a current error signal can be derived.
A switch-mode power amplifier circuit as claimed in any one of the preceding claims, in which the use of a plurality of power devices. operating an interlaced fashion, in order to increase the apparent operating frequency of the system, allows more feedback to be imposed on the system.
A switching-mode power amplifier circuit as claimed in any one of the preceding claims, in which the system is used to drive a load, particularly an electromagnetic load, using high power, low distortion waveforms with a high degree of control.
A switch-mode power amplifier circuit substantially as herein described with reference to and as shown in FIGS. 3 to 9 of the accompanying drawings.
Dependencies are inferred from the claim text.