Improvements relating to R.F. Heating Apparatus

Abstract

Abstract 1,159,279. Automatic tuning. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. 16 Jan., 1968 [25 Jan., 1967], No. 3692/67. Heading H3A. In a microwave heating apparatus, the resonator or resonators 16, 17 forming the application is maintained in tune with the generator 15 by comparing the phase of the incident and reflected energy to derive an error signal which retunes the resonators. The incident and reflected signals are coupled to a detector 31 by four-part couplers 19, 30 or in the case of a single resonator by one three-part coupler (41), Fig. 5 (not shown). By adjusting phase shifter 33 the detector output may be arranged to vary about a datum level V R , and this may be backed off in amplifier 34 to give an error control signal for motor 24 which varies about zero. The motor adjusts tuning screws 22, 23 in the cavities.

Inventors

• 👤 Roger John Meredith

Bibliographic Details