Title :
Ku-band solid state power amplifier for Geosat follow-on
Author :
Abernathy, Paul C. ; Dobrzanski, Joseph R. ; Smith, Matthew C. ; Griswold, Michael S. ; Burnsed, Millage G. ; Sherman, James R.
Author_Institution :
ECI Div., E-Syst. Inc., St. Petersburg, FL, USA
Abstract :
A compact 7 W (peak) Ku-band solid state power amplifier (SSPA) has been designed and developed for the Navy´s Geosat follow-on (GFO) radar altimeter. This amplifier combines the output of two 5 W internally matched MESFETs with an integral waveguide combiner, and uses an external isofilter to protect the SSPA from load variations and to suppress 2nd and 3rd harmonics to -60 dBc. Drain voltage switching was implemented using a novel modulator design. An automatic levelling control (ALC) circuit maintains constant output power at end of life (EOL) over varying input and environmental conditions. AM/PM conversion was measured at 4.4 degrees peak/dB and the phase linearity was measured at 12.0 degrees p-p. A discussion is included on various growth options and new devices applicable for the future in remote sensing applications such as SeaWinds II, NPOESS, and GFO2
Keywords :
microwave power amplifiers; modulators; power amplifiers; power combiners; radar altimetry; remote sensing by radar; spaceborne radar; 2nd harmonics suppression; 3rd harmonics suppression; 5 W; 7 W; AM/PM conversion; GFO2; Geosat follow-on radar altimeter; Ku-band solid state power amplifier; NPOESS; SeaWinds II; automatic levelling control circuit; drain voltage switching; end of life; external isofilter; internally matched MESFET; load variation protection; modulator design; phase linearity; radar altimeter; remote sensing applications; waveguide combiner; Automatic control; Automatic logic units; Load management; MESFETs; Phase measurement; Power amplifiers; Protection; Radar; Solid state circuits; Voltage;
Conference_Titel :
Southeastcon '96. Bringing Together Education, Science and Technology., Proceedings of the IEEE
Conference_Location :
Tampa, FL
Print_ISBN :
0-7803-3088-9
DOI :
10.1109/SECON.1996.510073
