Radio-frequency inverters with transmission-line input networks
Year: 2006
Type: conference-paper
Abstract: A soft-switching inverter topology (the Class Φ) is presented which draws dc source current through a transmission line or a lumped-network approximation of a distributed line. By aligning the inverter switching frequency just below the line's λ/4-wave resonance, the Class Φ topology enforces odd-and even-harmonic content in its drain voltage and input current, respectively. The symmetrizing action of the transmission-line dynamics results in natural square-wave operation of the switch, reducing the inverter stresses (relative to a Class E) for a given power throughput. The inverter waveforms and normalized power-output capability are analyzed in simple terms, and supported by measurements of an inverter built around a length of distributed line, and an inverter incorporating a lumped L-C ladder network. The latter implementation is constructed with air-core magnetics and inter-layer capacitances that are integrated into the thickness of a printed-circuit board. A comparison with a Class Ε inverter of similar size and ratings demonstrates the small passive-component values and manufacturing advantages afforded by the Class Φ topology.
Institution: Massachusetts Institute of Technology
Language: English
Topic: Advanced DC-DC Converters
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1557524079