I would like to improve my understanding of how much power or current a capacitor can handle. The application that drives my interest - impedance matching for RF applications for ham radio gear. I found some info on surface mount capacitors but very little on ceramics, silver mica and so on. Yes, there is stuff on the monster parts used in broadcast transmitters but it's not much help to me. I've seen the stuff on electrolytics for pulse applications. ESR is part of it but not all I need.
All capacitors have some losses which heat the device. Most capacitors have leads and other conductive paths that must have some limit to what they can handle but little is published on those limits. I did manage to get a call from a capacitor manufacturer who have me a rough guide for the heat dissapation of garden variety capacitors in terms of watts per square inch to limit temp rise. The question for me: will the device overheat as the frequency increases before the voltage rating of the capacitor is exceeded.
In the end what I would like to do is construct an antenna "tuner" that uses relays and fixed capacitors and have some assurance that it will withstand the 300 watts that I'll apply with my transmitter. Several manufacturers make them (tuners) with silver mica caps but they all seem to limit power handling to 100 watts. Traditionally the capacitors have been large variables or bread-slicers where temp isn't much of an issue.
All capacitors have some losses which heat the device. Most capacitors have leads and other conductive paths that must have some limit to what they can handle but little is published on those limits. I did manage to get a call from a capacitor manufacturer who have me a rough guide for the heat dissapation of garden variety capacitors in terms of watts per square inch to limit temp rise. The question for me: will the device overheat as the frequency increases before the voltage rating of the capacitor is exceeded.
In the end what I would like to do is construct an antenna "tuner" that uses relays and fixed capacitors and have some assurance that it will withstand the 300 watts that I'll apply with my transmitter. Several manufacturers make them (tuners) with silver mica caps but they all seem to limit power handling to 100 watts. Traditionally the capacitors have been large variables or bread-slicers where temp isn't much of an issue.