Title :
Improved noise characteristics of an X-band helix-TWT combined with a low noise solid state amplifier
Author :
Joo, Ji Han ; Son, Min Ho ; Lee, Yong Duk ; Choi, Jin Joo
Author_Institution :
Dept. of Radio Sci. & Eng., Kwangwoon Univ., Seoul, South Korea
Abstract :
Significant reduction of noise figure can be realized by partitioning the high TWT gain about equally between the SSA (solid state amplifier) and the TWT. We report the design study and experimental results of an X-band power amplifier module, consisting of a low-noise SSA and a low-gain helix-TWT. The module consists of the low noise SSA and a low gain TWT. The SSA is a two-stage amplifier where the second stage is configured as a balanced amplifier. The balanced amplifier is designed for achieving a low VSWR and doubling the amplifier power. The active devices of first and second stage amplifiers are a NEC low noise hetero-junction FET and two Mitsubishi power GaAs FETs. The TWT produces a maximum amplified power of 14 W, corresponding to saturated gain of 25.4 dB and efficiency of 21.6 % with a single stage depressed collector.
Keywords :
circuit noise; differential amplifiers; microwave power amplifiers; travelling wave tubes; 14 W; 21.6 percent; 25.4 dB; 9.5 GHz; TWT noise characteristics; VSWR; X-band TWT; balanced amplifier; hetero-junction FET; low noise solid state amplifier; low-gain helix-TWT; power FET; power amplifier module; single stage depressed collector; two-stage amplifier; Distortion measurement; Frequency; Gain; High power amplifiers; Low-noise amplifiers; Noise figure; Noise measurement; Noise reduction; Phased arrays; Solid state circuits;
Conference_Titel :
Vacuum Electronics Conference, 2004. IVEC 2004. Fifth IEEE International
Print_ISBN :
0-7803-8261-7
DOI :
10.1109/IVELEC.2004.1316218
