What you can find in a microwave oven
A microwave oven is the better source of HV components; you can find a 2Kv @ 500mA transformer, a diode capable of 6000V peak at 0.5A, a 1uF 2KV capacitor, a magnetron, one or two motors and a control board rich in relais, integrated circuits etc.
This component is a high-vacuum tube with anode connected to the case and cathode composed by a heater. When it is supplied with about 3 KV dc at about 500mA, it produces microwave. In a mobile device the heater can be supplied with 12 V max at about 3.5 A and the magnetron can withstand pulses up to 30Kv. Pay attention using the magnetron outside the oven case...it will cook everything in front of its waveguide.
The entire magnetron: over the white support there are the heater (kathode) connections, the body is the anode.
The output antenna
The bottom of the magnetron
The magnetron with the cover removed: there are two chockes to protect the heater power supply from RF