Harmonic analysis approach to the "TunneLadder": A modified Karp circuit for millimeter-wave TWTA\´s

A field approach to the summed harmonic analysis of the "TunneLadder" structure--a modified forward-wave Karp circuit-is developed by Combining TM01and TE11modes. Results suggest the suitability of this structure as a high impedance, about 1-percent bandwidth circuit, millimeter-wave forward-wave-type amplifier that is voltage tunable over about a 5-percent frequency range and has excellent power handling ability. Theory gives good agreement with experimental results obtained by Karp in ω-β dispersion and predicts qualitatively the appearances of the antisymmetric mode discussed and of the so called "Hightron" mode that was discussed earlier in [7] and [8], in addition to the desired symmetric mode.