MICROWAVE GENERATORS DESIGN USING AN ADJUSTED METHOD

Abstract

Electrical schemes are employed that act on two main parameters namely: on the magnetic field of the magnetron and on the anode voltage of the magnetron. The magnetic field allows for the adjustment of the output power in microwave by creating in the anode - cathode space of the magnetron of a magnetic induction „B“ perpendicular on the movement direction of the electrons emitted by the cathode. Magnetic field lines modify the trajectory of the electrons emitted by the cathode, and if the magnetic field value is high enough, the electrons do not reach the anode and so the exit power in microwaves becomes zero. The magnetic field that determines the nullification of the power exited in microwave is called critical magnetic field. The adjustment system for the output power in microwaves is presented above; it is employed for magnetrons fitted with electromagnet and maximum output in microwave power of about 5,5 kW. The adjustment scheme consists in the utilisation of thyristors or triacs connected in the primary winding of the transformer of anode voltage and the adjustment of the supply voltage of the primary winding of the transformer through the command of their opening angle.