A supply method of increasing the lifetime of the emission tube in the power radiofrequency transmitters

In this paper, some supply techniques for the vacuum tube used in the output stage of a power radiofrequency (RF) amplifier are proposed and studied. These techniques may increase the tube life span and they reduce the operating costs with the power RF transmitter. A complete block diagram of the tube power supply unit and an algorithm to control the tube electrodes supply voltages are carried out. The proposed circuit operates the vacuum tube with a decreased filament voltage, withal maintaining the RF output power at the same level as in the normal operation, at the nominal filament voltage. Although the design is intended to be used in Frequency Modulation (FM) RF equipment from particle accelerators, it may be successfully implemented in any power amplifier which uses vacuum tubes.