Coherent PSK Subcarrier Demodulator - PDM001 - GDP Space Systems - Telemetry Systems, Synchronizers, BERTS, Demodulaters, Modulators, Receivers, Frame Synchronizers, decommutator, Simulators

The PDM001 Subcarrier Demodulator performs coherent demodulation of Binary Phase Shift Keyed (BPSK) and optionally Quadrature Phase Shift Keyed (QPSK) subcarriers. The input subcarrier frequency range is from 1 kHz to 10 MHz.

Band-pass filtering of the input signal is accomplished by programming the cutoff points of Subcarrier High-Pass and Low-Pass Bessel filters. The filters attenuate adjacent subcarriers allowing the PDM001 to operate with wide-band input signals containing many subcarriers. The high and low-pass filters are independently bypassed if desired.

Features

BPSK (QPSK Optional)
Tunable Sub-carrier

1 kHz to 10 MHz

Tunable Data Bandwidth

1 kHz to 10 MHz

Tunable Sub-carrier Filtering

1 kHz to 10 MHz

Tunable Loop Bandwidth

1 to 32 kHz ?0.707 dampingFour Input Connections
Edge Panel - two
P2 VME connector - two

Selectable Input Impedance

Low = 50 Ohms
High = 10k Ohms

Status Indications

Loop Deviation
Loss of signal

VME setup Control and Status read-back

The PDM001 demodulator employs a Costas Loop to achieve coherent carrier recovery and automatic gain control (AGC). The input signal is multiplied by the sine and cosine of a local oscillator (NCO) resulting in a spectrum that is Bessel filtered to provide the data and phase error indications. The data and phase error channels are sampled, converted to equivalent digital values and subsequently processed by a Digital Phase Lock Loop (DPLL), a Digital Sync Detector (DSD) and a Digital AGC circuit. Phase differences between the input sub-carrier and the NCO are corrected by the DPLL while the DSD detects carrier phase synchronization and provides lock status.

The Digital AGC circuit produces 30 dB of dynamic range allowing the user to handle 50 mVp-p signals as effectively as TTL BPSK modulated signals (5 Vp-p).

The PDM001 operates under software control via the VME bus. The module utilizes eight 16-bit registers to contain all operational control parameters to govern the PDM001. Two status read-back registers contain all information needed to monitor the operation of the demodulator. One of Four inputs is program selectable to be applied to the demodulator. Input impedance is selectable to be either 50 ohms (optional 75 ohms) or 10K ohms.


			[ Home \| Products \| Support \| Events \| Contact us ] © 2004 GDP Space Systems - a division of Delta Information Systems, Inc.

The PDM001 Subcarrier Demodulator performs coherent demodulation of Binary Phase Shift Keyed (BPSK) and optionally Quadrature Phase Shift Keyed (QPSK) subcarriers. The input subcarrier frequency range is from 1 kHz to 10 MHz. Band-pass filtering of the input signal is accomplished by programming the cutoff points of Subcarrier High-Pass and Low-Pass Bessel filters. The filters attenuate adjacent subcarriers allowing the PDM001 to operate with wide-band input signals containing many subcarriers. The high and low-pass filters are independently bypassed if desired.
Features
BPSK (QPSK Optional) Tunable Sub-carrier 1 kHz to 10 MHz Tunable Data Bandwidth 1 kHz to 10 MHz Tunable Sub-carrier Filtering 1 kHz to 10 MHz Tunable Loop Bandwidth 1 to 32 kHz ?0.707 dampingFour Input Connections Edge Panel - two P2 VME connector - two Selectable Input Impedance Low = 50 Ohms High = 10k Ohms Status Indications Loop Deviation Loss of signal VME setup Control and Status read-back
The PDM001 demodulator employs a Costas Loop to achieve coherent carrier recovery and automatic gain control (AGC). The input signal is multiplied by the sine and cosine of a local oscillator (NCO) resulting in a spectrum that is Bessel filtered to provide the data and phase error indications. The data and phase error channels are sampled, converted to equivalent digital values and subsequently processed by a Digital Phase Lock Loop (DPLL), a Digital Sync Detector (DSD) and a Digital AGC circuit. Phase differences between the input sub-carrier and the NCO are corrected by the DPLL while the DSD detects carrier phase synchronization and provides lock status. The Digital AGC circuit produces 30 dB of dynamic range allowing the user to handle 50 mVp-p signals as effectively as TTL BPSK modulated signals (5 Vp-p). The PDM001 operates under software control via the VME bus. The module utilizes eight 16-bit registers to contain all operational control parameters to govern the PDM001. Two status read-back registers contain all information needed to monitor the operation of the demodulator. One of Four inputs is program selectable to be applied to the demodulator. Input impedance is selectable to be either 50 ohms (optional 75 ohms) or 10K ohms.