Telemetry Receivers / Demodulators & Downlink: RF, IF & Sub-Carrier

Model 4425 RF Single/Dual/Quad Channel Tunable Receiver/Demodulator/Bit Synchronizer (2U Chassis)
Model 4425

The Model 4425 Digital RF Receiver is available in single or dual channel configurations in a 2U rack-mounted chassis. Each channel is completely independent and includes an integrated solution consisting of an RF Signal Processor, 2 Demodulators, 2 optional Bit Synchronizers and 2 Frame Synchronizers. This state-of-the art receiver provides a compact, cost competitive, flexible solution to a wide variety of communications link scenarios.

The Model 4425 processes 3 RF Bands: S Band, 2185 MHz to 2485 MHz; Upper L Band, 1700 MHz to 1850 MHz; Lower L Band 1427 MHz to 1545 MHz. Additional RF bands are available (i.e. P Band 550 MHz to 1100 MHz). Depending upon specific user requirements, a choice of 4 IF filters are available.

The demodulation process, as well as the baseband bit synchronization process, is totally performed in the digital domain. Signal acquisition is performed by scanning the IF within the programmed acquisition band centered about the selected Carrier frequency. PM / PSK waveforms are additionally scanned for acquisition at the subcarrier frequencies. Once signal acquisition is complete, synchronized signal tracking is performed whereby continuous validation of the lock state is maintained.

A variety of optional FEC decoders are available and two fully programmable frame synchronizers (pattern detection) are provided with the bit synchronizer option.

With the Bit Synchronizer option, data is output via a pair of TTL and RS-422 outputs. The unit supports an optional Ethernet output mode in which frame synchronized byte aligned data can be output via an Ethernet port with start of frame identified.

An Encapsulated data and data quality output may be included that supports the GDP Best Source Selector products.

  1. Up to 4 Channels per 2U Box
  2. Form Factor
  3.      • 2U Rack-Mountable Chassis
  4. Noise Figure
  5.      • < 10 dB
  6. Wide Dynamic Range
  7.      • > 80 dB
  8. RF Frequencies
  9.      • 2185 MHz to 2485 MHz
         • 1700 MHz to 1850 MHz
         • 1427 MHz to 1545 MHz
         • 180 MHz to 1100 MHz *
         • Others Available
  10. Multi-Waveform Demodulation
  11.      • BPSK, QPSK, OQPSK
         • UQPSK *, AQPSK *
         • SOQPSK (ARTM Tier 1) *
         • Analog FM & PCM/FM *
         • GMSK*
         • Multi-Symbol PCM/FM*
  12. 3 Demodulators (Per Channel)
  13.      • PCM / PSK*
         • 1 RF, 2 SC * (Per Channel)
  14. 2 Bit Synchronizers (Per Channel)*
  15.      • 50 bps to 10 Mbps BPSK (20 Mbps *)
         • 50 bps to 20 Mbps QPSK (40 Mbps *)
         • 2 Viterbi Decoders *
             • R=1/2, 1/3, 2/3, 3/4/ 5/6, 7/8
         • Reed-Solomon *
         • HDLC / AX.25 (e.g. CUBESAT)
  16. 3 Frame Synchronizers per Channel
  17. Byte Aligned Ethernet Data Output*
  18. Best Source Selector Compatible Output*
  19. Tracking Antenna Control Support*
  20.      • Envelope / Coherent AM*
         • SNR*
  21. IRIG-B*
  22.      • Input, Output
  23. Chapter 10 Compatible Output*
  24. Remote Control
  25.      • Ethernet & RS-232 (Std)
         • IEEE 488 *

* OPTIONAL
Input:
RF Frequency:
2185 MHz to 2485 MHz & 1700 MHz to 1850 MHz & 1427 MHz to 1545 MHz or 550 MHz to 1100 MHz *
Noise Figure:
< 10 dB
IF Filters:
4 selectable filter bandwidths (Standard set provided)
Dynamic Range:
> 80 dB
Input Impedance:
50 Ohms
VSWR:
< 2:1

Demodulation:
IF Acquisition / Tracking Range:
255 kHz:
Loop Bandwidth:
0.01% to 1% of Bit Rate (Analog PM 2 Hz to 20 KHz)

PM Demodulator:
Frequency Response:
100 Hz to 15 MHz
Modulation Index:
0 to 2.8 Radians

PSK Demodulators:
Types:
1 IF, 1 SC *
Modulation Waveforms:
BPSK, QPSK, OQPSK, UQPSK *, AQPSK *, GMSK *, SOQOSK ARTM Tier 1 *
Locking Threshold:
6 dB Eb/No

PCM/FM Demodulator*:
Data Rate:
1 kHz to 20 Mbps (30 Mbps *)

Bit Synchronizer(s): (Option)
Bit Rate:
50 bps to 10 Mbps BPSK (20 Mbps *) 100 bps to 20 Mbps QPSK (40 Mbps *)
Input Codes:
NRZ-L,M,S; BIΦ-L,M,S
Output Codes:
NRZ-L
Viterbi Decoder:
* Rate 1/2, 1/3, 3/4, 7/8, ...options
Descrambler:
V.35 / V.36 (CCITT/ Intelsat)

Data Output
Analog
TTL, RS422 (Standard
Ethernet Data Output (IRIG-106 Ch-10, HDLC/AX.25)*
Encapsulated Data & Quality that supports GDP Best Source Selector *

Control Interface:
Ethernet & RS-232 (Standard)
IEEE 488 *

Environment:
Temperature:
10°C to 50°C Operational; -40°C to 85°C Storage

Status Output:
Signal Present, Carrier Lock, Bit Synchronization Lock, Viterbi Lock, Frame Lock, Doppler

*OPTIONAL