LOW NOISE DOWN-CONVERTER
Low noise down-converter is intended for application in receiving equipment of tropospheric station as low noise selective tuned converter of 4400…5000 MHz microwave signals into the 70 MHz IF signals. The up-converter is executed under the superheterodyne scheme with single frequency conversion of with using an external local oscillator. Set-up of low noise down-converter on the specified input frequency is performed remotely by using the controller which tunes the LO frequency- synthesizer frequency simultaneously with the tuning of low noise down-converter filter- preselector. There are three inputs in low noise down-converter: main microwave input (signal input), input of receiving channel automatic monitoring signals and LO input.
Specifications
Operation frequency range, MHz: of input signals
of LO
of output signals
of input pilot signals
of output pilot signals | 4400...5000
4330...5070
64,5...75,5
64,5...75,5
4386...5014
56±1, 84+1 | Microwave input
Input of transmitter frequency ynthesizer
IF output
70MHz output, control
Receiver small circle input
Pilot signal output |
| Gain of main and control channels of input operating frequency range, dB | 50 ±2 | |
| Max gain ripple of main and control channel at output operating frequency range, no more | 1 | |
| Noise factor, no more, dB | 0,8 | |
Selectivity, no more, dB
at image channel
at Fo ±12 МГц offset | 65
30 | |
| 3rd intermodulation distortion measured according to 2 tone test (at 2 MHz spacing with minus 50 dBm power signals) | 45 | |
| Blocking factor by interference with minus 25 dBm level at Fo not less ±140, no more, dB | 1 | |
| Input VSWR,no more | 1,2 | |
| VSWR of IF main and control outputs, no more | 1,3 | |
| VSWR of LO coax input, no more | 1,3 | |
Transfer ratio in operating frequency range of pilot signals, dB:
from microwave input to pilot signal output
from small circle receiver input to pilot signal output |
3 ±5
-23 ±5 | |
| Input VSWR of small circle receiver, no more | 1,2 | |
| VSWR of pilot signal output, no more | 1,3 | |
Consumption current, no more, A:
+27 V for analogue circuits
+27 V for digital circuits
+12 V |
0,4
0,1
0,7 | |
| Time between failures, hours | 38000 | |
|
TM
