Abstract:
An isolation transformer for a cathode heater supply for a microwave source has a first U- shaped secondary winding (421), comprising two parallel leg portions joined at one end thereof by a bridging portion. A primary winding (422) is located around and concentric with a portion the bridging portion. A monitor winding passes through primary core assemblies of the primary winding. Electrical insulation (115) insulates the secondary winding from the primary winding. For a DC cathode heater supply a second U-shaped secondary winding is spaced from and aligned with the first U-shaped secondary winding and first and second smoothing chokes comprising respective core assemblies (1127, 1129) are fitted over connection leads arranged for connecting two ends of the first secondary winding to the cathode heater. Synchronised rectifiers are connected between the secondary windings and the first smoothing choke; and control means are provided for the synchronised rectifiers.
Abstract:
A high frequency cathode heater supply for a microwave source includes a SMPS inverter (13) and an isolation transformer (12) having a primary winding (122) arranged to be powered by the SMPS inverter, a monitor winding (123) passing through primary core assemblies of the primary winding and a secondary winding (121) arranged for connection to the cathode heater (11). A current monitor (141) is arranged to monitor a current in the primary windings. Signal processing modules (14, 131, 132) are arranged to receive a first input signal from the monitor winding (123) indicative of a voltage Vh across the cathode heater (11) and a second input signal from the current monitor (141) indicative of a current through the cathode heater. The signal processing modules are arranged to output a control signal to the SMPS inverter to control power supplied to the cathode heater dependent on a monitored resistance of,or monitored power supplied to, the cathode heater as determined from the first input signal and the second input signal.
Abstract:
The present invention pertains to the field of magnetrons, wherein the purpose of said invention is to provide a more efficient use of the working surface in field emitters and to increase device reliability in conditions of increased mechanical activity. To this end, the structure of a magnetron comprises an anode as well as a cathode arranged coaxially inside the anode, wherein said cathode comprises a secondary emitter and a field emitter as well as side flanges used as focalisation screens. One at least of said focalisation screens is electrically isolated from the secondary emitter and comprises at least one field emitter having its working end directed towards the surface of said secondary emitter.
Abstract:
A 4G magnetron is disclosed. The magnetron may include an anode, having a cylindrical member and anode vanes disposed within the cylindrical member which define resonant cavities therebetween, and a dispenser cathode, suitable for heating and located coaxially within said anode. The magnetron may operate in a temperature range of about 850-1050 C. The magnetron may include conductive cooling. The magnetron may comprise inventive anode and cathode structures. A method for preparing a plurality of magnetron tubes substantially simultaneously is further provided.