1. EVLA Front-End CDR – Solar Mode
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

2. EVLA Front-End CDR – Solar Mode
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.
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

3. Generic Receiver (One Polarization Shown)
LNA
Polarizer
Noise
Diode
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

4. Generic Receiver (One Polarization Shown)
LNA
Polarizer
Noise
Diode
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

5. Generic Receiver Solar Additions
LNA
HNA
Polarizer
Noise
Diode
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

6. New Components Required
“High Noise” amplifier (2)
SPDT RF switch (2)
Steppable (vs. fixed) attenuator (1)
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

7. EVLA Front-End CDR – Solar Mode
Amplifier Power Out
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

8. Additional Requirements
Requires accurate “cal” values.
Requires phase transfer between modes.
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006

9. EVLA Front-End CDR – Solar Mode
Conclusions
No compromise of “normal” observing.
Accommodates wide input range.
Few additional components.
Can be added later without major rebuild.
Paul Lilie
EVLA Front-End CDR – Solar Mode
April 24, 2006