21apr10- system block
diagram (dana)
(old....18feb04-
system block diagram (lisa wray)
05apr08-
System Temperature/powerLevels (bsisk)
05apr08- Eddie's down
conversion box
05apr08- Fiber Span AC231, Fiber Optic Xmtr/Rcvr
measurements by bsisk
05apr08
Eddies down conversion box:
Eddies down conversion box takes the output of the
alfa filter bank, amplifies, downconverts, filters, amplifies, and then
sends the IF signal down the fiber.
Specs for
Eddies down conversion box.
Component
|
Make
|
GAIN
db
|
CumGain
db
|
NF
db
|
Compression
(1db)
|
Level@1db
compression
|
Notes
|
RF amp
|
MGA-86576 (avago)
|
+21(20)
|
20
|
2.2
|
+6 dBm
|
-27
|
amp bias
|
mixer
|
IAM-8 (avago)
|
+15
|
35
|
19
|
+8dBm
|
+7
|
|
Filter
|
P7LP507 (coil craft)
|
-.5
|
34.5
|
|
|
6.5
|
500Mhz Lowpass.
|
IF
amp
|
MAV-11SM (mini circuits)
|
+12(11)
|
45.5
|
3.6
|
+17dBm
|
16.5
|
AmpBias |
Fiber
Modulator
|
AC231 (Fiber Span)
|
-.8
|
44.7
|
39
(-135dBm Hz)
|
+15dBm
|
|
See fiber
TX notes
|
- Fiber
Tx Notes (from fiber span rep:)
- For a clean(i.e., very linear) signal, we recommend staying 10
dB or more below the 1dB compression point, putting the "peak linear
power" at +5 dBm.
- The damage threshold for these devices is an input power of +20
dBm. Please do not exceed this maximum, even for very short durations.
- Amp bias:
- The RF and IF amps are not
properly biased (according to the data sheets). Proper biasing caused
oscillations in the board. Ganesh thinks that the actual biasing may
decrease the gain of the combined amps by up to 3db.
- Input Levels for compression:
- -27Dbm at input to RF
amp will cause 1 db compression at mixer output (assuming 20 db gain
for misbiased RF amp).
- Input Levels for damage to fiber
Optic transmitter.
- A peak level of +20dBm
will damage the fiberOpticTx.
- With +45 db gain
- a -25 dBm signal would cause problems if No compresssion.
- a -27 dBm signal will be 1db compresses at the mixer output.