Use of a variable frequency source with a single-mode cavity to process ceramic filaments
Rapid feedback control is needed for practical microwave processing of continuous ceramic oxide filaments to regulate the process temperature where the -dielectric properties of the filaments change rapidly with temperature. These dielectric changes can produce large rapid changes in the resonant frequency, the reflectivity, and the power density of the cavity. A broadband traveling wave tube (TWT) amplifier provides a highly versatile process control platform for filament processing. By comparing a RF signal from the cavity to a reference signal from the TWT, phase information can be used in a negative feedback loop to allow the oscillator to track the cavity frequency as it shifts due to the changing dielectric constant in the filaments being heated. By sampling the electric field level in the cavity with a detector, amplitude control can be done to maintain a constant absorbed power in a fiber tow, which is important for controlling the tow heating and temperature. This paper describes the design and testing of feedback controller with mullite rods in a single-mode TE{sub 10n} resonator driven by a commercial TWT.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 103519
- Report Number(s):
- LA-UR-95-2419; CONF-9509204-2; ON: DE95016889
- Resource Relation:
- Conference: Microwave and high frequency heating, Cambridge (United Kingdom), 17-21 Sep 1995; Other Information: PBD: [1995]
- Country of Publication:
- United States
- Language:
- English
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Use of a variable frequency source with a single-mode cavity to process ceramic filaments
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