NGA-201A DRM-AM Modulator
The Newglee NGA-201A DRM-AM Modulator is a professional, embedded-platform DRM broadcasting device providing DRM channel coding and OFDM modulation. It accepts DRM multiplex streams in MDI/DCP format and generates I/Q signals compliant with ETSI ES 201 980 and GY/T 423-2025. With peak-to-average power ratio reduction, it effectively increases the average output power of the transmitter. An integrated AM transmitter adapter supports the DRM upgrade of PDM, PSM and DX-type AM broadcast transmitters.
- Channel Coding and OFDM Modulation: converts MDI/DCP streams into I/Q signals compliant with ETSI ES 201 980 and GY/T 423-2025
- Peak-to-Average Power Ratio Reduction: lowers the PAPR of OFDM signals to improve transmitter efficiency
- Digital Predistortion: optimizes signal quality through compensation
- Multiple Output Modes: supports I/Q signals, envelope/phase modulation signals and direct RF output, adapting to a wide range of transmitters
DRM Mode A/B/C/D Modulation
- Performs DRM Mode A/B/C/D modulation of the MDI/DCP stream, providing DRM-compliant I/Q or A/RFP output.
High-Performance Digital Signal Processing
- Integrates digital predistortion (DPD), adaptive linear and non-linear precorrection, and PAPR (peak-to-average power ratio) reduction, significantly improving system performance and transmission efficiency.
Direct Digital Synthesis (DDS)
- Employs near-RF direct digital frequency synthesis for higher signal fidelity and stability.
- Highlights
- Specifications
- Documentation
The NGA-201A DRM Modulator is a key part of the terrestrial audio broadcasting system and serves as the core component of an AM transmitter. Compliant with the DRM standards ETSI ES 201 980 and GY/T 423-2025, it integrates DRM baseband processing, digital signal synthesis, up-conversion, digital-to-analog (D/A) conversion, RF output, audio input/output, and monitoring and control panel modules. It seamlessly converts the multiplex stream from the encoding multiplexer into I/Q or A/RFP signals.
Through direct digital frequency synthesis and an optional digital up-converter, the NGA-201A brings the digital domain closer to the RF stage than ever before. Combined with advanced digital signal processing and digital predistortion algorithms, it delivers exceptional system performance.
In addition, the modulator provides a Web/RS232 monitoring interface for convenient management of its operating status. It also supports upgrades over the network, enabling remote and unattended operation of the entire transmission system.
Core Features
- Multiplex stream input: supports MDI/DCP stream input
- Operating modes: compatible with modes A/B/C/D
- Mapping: standard QAM / symmetrical hierarchical / asymmetrical hierarchical
- Interleaving depth: 0.4 s short interleaving / 2 s long interleaving
- Supported bandwidths: 4.5 / 5 / 9 / 10 / 18 / 20 kHz
- Code rates: 1/4 to 8/9
- Clock source: 10 MHz internal/external clock, 1 PPS synchronization
- Network synchronization: single-frequency / multi-frequency network synchronization
- Dynamic reconfiguration: run-time parameter adjustment
- Spectrum compliance: conforms to ITU-R requirements
- Built-in PAPR reduction
- Output interfaces: digital I/Q output, amplitude/phase modulation (A/RFP) output, RF output
| Item | Parameter |
|---|---|
| Audio Source Input | MDI/DCP multiplex stream input via IP network port |
| Modulation and Channel Coding | |
| Robustness modes | A, B, C, D |
| Bandwidth (kHz) | 4.5, 5, 9, 10, 18, 20 |
| Interleaving depth | 400 ms, 2 s |
| Constellation mapping | 4QAM, 16QAM, 64QAM |
| Error-correction code | Convolutional coding, all code rates within the standard |
| Protection levels | EEP, UEP |
| RF Output (optional, models with RF output only) | |
| Center frequency | 100 kHz – 30000 kHz, adjustable in 1 kHz steps |
| RF output signal level | -30.0 to +10.0 dBm |
| Level stability | < ±0.2 dB (24 hours) |
| Frequency stability | Internal reference: <1×10⁻⁷ External reference: <1×10⁻¹⁰ |
| MER (Modulation Error Ratio) | >50 dB |
| Shoulder ratio | < -60 dBc |
| Phase noise | < -90 dBc/Hz @ 10 Hz < -110 dBc/Hz @ 100 Hz < -120 dBc/Hz @ 1 kHz < -120 dBc/Hz @ 10 kHz < -125 dBc/Hz @ 100 kHz < -135 dBc/Hz @ 1 MHz |
| Output connector | N-type female, 50 Ω impedance |
| Reference Clock: Internal | |
| Stability | < ±0.01 ppm (typical) |
| Aging rate | < ±0.3 ppm/year |
| Reference Clock: External 10 MHz | |
| Input level | AC-coupled, VP-P ≥ 300 mV |
| Input connector | BNC female, 50 Ω input impedance |
| Control Modes | |
| Local control | Six-button front panel, 40×2 backlit English LCD, status indicators |
| Remote control | Web interface, RS232/RS485/network monitoring, remote upgrade support |
| Monitoring and Alarms | |
| RF oscillator unlock | |
| Over-temperature | |
| Audio source input interruption |