Second harmonic suppression in helix traveling-wave tubes
A filter structure to suppress the second harmonic component in the RF signal of a traveling-wave tube (TWT) was developed and integrated into a helical delay line. Its effect is shown in simulation and measurement.
Filter helix implementation into an S-band TWT design
The performance of an S-band traveling wave tube (TWT) is enhanced by introducing a filter consisting of periodic transmission line discontinuities into its delay line. The filter is designed to suppress the second harmonic which is particularly strong in this tube especially at low frequencies. The main goal, i.e. to improve the electron velocity spectrum at the lower operating band and, thus, to extend the bandwidth of the tube, is demonstrated.
Simulation of the BWO Threshold Current in a Helix TWT
The BWO threshold current of a helix TWT is simulated using the self-consistent 2.5D interaction code MVTRAD. The effect of different tube parameters on the threshold current is evaluated, and BWO countermeasures are investigated. The simulated results are compared to measurements