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EVLA Front-End CDR. Solar Mode. Solar Power Levels. 1 SFU = 10 4 Jy = 1250 Kelvins at VLA Max. flare = 100,000 SFU “Normal” Tsys ~~ 25 K = 0.02 SFU Max/Normal = 67 dB range. Receivers & Noise “Cal” must accommodate 67 dB range. Generic Receiver (One Polarization Shown ). LNA.
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EVLA Front-End CDR Solar Mode EVLA Front-End CDR – Solar Mode April 24, 2006
Solar Power Levels • 1 SFU = 104 Jy = 1250 Kelvins at VLA • Max. flare = 100,000 SFU • “Normal” Tsys ~~ 25 K = 0.02 SFU • Max/Normal = 67 dB range. • Receivers & Noise “Cal” must accommodate 67 dB range. EVLA Front-End CDR – Solar Mode April 24, 2006
Generic Receiver(One PolarizationShown) LNA Polarizer Noise Diode EVLA Front-End CDR – Solar Mode April 24, 2006
Generic Receiver(One Polarization Shown) LNA Polarizer Noise Diode EVLA Front-End CDR – Solar Mode April 24, 2006
Generic ReceiverSolar Additions LNA HNA Polarizer Noise Diode EVLA Front-End CDR – Solar Mode April 24, 2006
New Components Required • “High Noise” amplifier (2) • SPDT RF switch (2) • Steppable (vs. fixed) attenuator (1) EVLA Front-End CDR – Solar Mode April 24, 2006
Amplifier Power Out EVLA Front-End CDR – Solar Mode April 24, 2006
Additional Requirements • Requires accurate “cal” values. • Requires phase transfer between modes. EVLA Front-End CDR – Solar Mode April 24, 2006
Conclusions • No compromise of “normal” observing. • Accommodates wide input range. • Few additional components. • Can be added later without major rebuild. EVLA Front-End CDR – Solar Mode April 24, 2006