TY - CHAP

T1 - Stability analysis of a TWT against the reflected signals using alarge-signal model.

AU - Srivastava, V.

AU - Joshi, S. N.

AU - Carter, Richard G.

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PY - 2000

Y1 - 2000

N2 - A large signal model is used to analyze the stability of a high gain helix TWT against the reflected signals caused by mismatches at its input and output terminations. The stability of a section of the tube in the presence of the reflected signals is determined by making a number of passes through the section for a very low drive power. A section is considered stable if the output power converges after 4 passes. If the output power goes on increasing or does not converge then the section is defined as unstable. Results are presented for a 60 W helix TWT which is designed both in a two-section and in a three-section configuration for a small-signal gain of more than 60 dB. It is shown that the two-section TWT can be made stable with 10 dB return loss at the input and output terminations, only if the tip loss profile at the sever can be designed to have a return loss of more than 30 dB. For the three-section tube, the return loss at the sever does not need to be greater than 20 dB for stable output performance.

AB - A large signal model is used to analyze the stability of a high gain helix TWT against the reflected signals caused by mismatches at its input and output terminations. The stability of a section of the tube in the presence of the reflected signals is determined by making a number of passes through the section for a very low drive power. A section is considered stable if the output power converges after 4 passes. If the output power goes on increasing or does not converge then the section is defined as unstable. Results are presented for a 60 W helix TWT which is designed both in a two-section and in a three-section configuration for a small-signal gain of more than 60 dB. It is shown that the two-section TWT can be made stable with 10 dB return loss at the input and output terminations, only if the tip loss profile at the sever can be designed to have a return loss of more than 30 dB. For the three-section tube, the return loss at the sever does not need to be greater than 20 dB for stable output performance.

U2 - 10.1109/ICMMT.2000.895625

DO - 10.1109/ICMMT.2000.895625

M3 - Chapter

SN - 0-7803-5743-4

SP - 80

EP - 83

BT - 2nd International ICMMT 2000 Conference on Microwave and Millimeter Wave Technology

PB - IEEE

CY - Beijing

ER -