Title :
Feedforward and predistortion linearizers on an X-band helix-TWT
Author :
Joo, Ji Han ; Son, Min Ho ; Lee, Yong Dug ; Choi, Jin Joo
Author_Institution :
Dept. of Radio Sci. & Eng., Kwangwoon Univ., Seoul, South Korea
Abstract :
Research on linearizing an X-band helix-TWT is performed. Both feedforward and predistortion linearizing circuits are designed and fabricated. Output frequency spectra are measured to compare the third order intermodulation distortion amplitudes of the TWT with linearization and without linearization. When a two-tone signal of 9.5 GHz and 9.505 GHz is injected with 6 dBm input power, the output power is measured to be 1.2 W and the third-order intermodulation distortion (IMD) is 45.6 dB. The third-order IMD is improved by 25.6 dB, compared with the TWT without the linearizing circuit.
Keywords :
feedforward; intermodulation distortion; linearisation techniques; microwave tubes; travelling wave tubes; 1.2 W; 9.5 GHz; 9.505 GHz; IMD; X-band helix-TWT; feedforward linearizer; linearization; predistortion linearizer; third order intermodulation distortion; two-tone signal testing; Circuits; Distortion measurement; Frequency measurement; Intermodulation distortion; Noise figure; Noise measurement; Nonlinear distortion; Power generation; Power measurement; Predistortion;
Conference_Titel :
Vacuum Electronics Conference, 2004. IVEC 2004. Fifth IEEE International
Print_ISBN :
0-7803-8261-7
DOI :
10.1109/IVELEC.2004.1316258
