2 TO 18 GHZ BROAD-BAND MICROWAVE-HEATING SYSTEMS

A wideband microwave heating system has been developed using a high po wer traveling-wave tube (TWT) amplifier and a highly overmoded applica tor cavity. The useful bandwidth is an octave or more with a single TW T and can be expanded by adding another TWT to cover a second band. Th e controlled, broadband processing techniques possible with this syste m result in uniformity of power distribution over areas not possible w ith more conventional fixed-frequency microwave heating approaches. Th is paper reports on a simple theoretical model of the variable frequen cy microwave concept and summarized the experimental results obtained to date. Applications include heat treating and sintering, polymer cur ing and plasma processing.