Alcatel‑Lucent 3EM09626AD – RF Transmitter (MDR‑8000 Series)

The Alcatel‑Lucent 3EM09626AD is a high‑performance RF transmitter module designed for the MDR‑8000 series digital microwave radio systems. Operating in the 2025‑2290 MHz frequency band, this transmitter is a critical component for point‑to‑point microwave links, providing reliable RF signal generation and amplification for long‑haul communication networks. It is engineered for carrier‑grade performance, offering excellent linearity, low phase noise, and high output power stability.

Frequency Range and Output Specifications

The transmitter covers the frequency range from 2025 MHz to 2290 MHz, with a typical output power of +23 dBm (200 mW) at the antenna port. The output power is adjustable over a 10 dB range via an internal attenuator, allowing fine‑tuning for link budget optimization. The module features a built‑in isolator to protect against load mismatch, ensuring stable operation even with varying antenna impedance. The spurious and harmonic suppression exceeds 60 dBc, meeting stringent spectral mask requirements.

Modulation and Signal Processing

The 3EM09626AD supports both analog FM and digital modulation schemes, including QPSK, 16‑QAM, and 64‑QAM, with symbol rates up to 20 Msps. The transmitter includes an internal upconverter that converts the intermediate frequency (IF) input to the final RF frequency. A precision synthesizer with a step size of 125 kHz provides frequency agility, and the phase‑locked loop (PLL) ensures low residual FM and phase noise. An automatic gain control (AGC) circuit maintains constant output power over temperature and supply variations.

Connectors and Interfaces

The module features an SMA‑female connector for RF output, a BNC connector for the IF input (70 MHz or 140 MHz), and a multi‑pin D‑sub connector for power, control, and monitoring signals. It includes analog voltage and current monitor outputs for forward and reflected power, enabling external power metering. A TTL‑level mute input allows remote disabling of the transmitter during maintenance or fault conditions.

Power Supply and Protection

The 3EM09626AD operates from a +15 V DC supply, consuming approximately 2 A at maximum output power. The module includes reverse‑polarity protection, overvoltage clamping, and thermal shutdown protection. A built‑in fan (for forced‑air cooled versions) ensures adequate heat dissipation. The transmitter is designed for continuous duty at ambient temperatures up to +55 °C.

Mechanical and Environmental Design

The unit is housed in a rugged aluminum enclosure measuring 130 mm x 80 mm x 30 mm, with threaded mounting holes for chassis integration. It is IP65 rated for dust and water resistance, suitable for outdoor or sheltered installations. Operating temperature range is ‑30 °C to +55 °C, and humidity tolerance is up to 95 % non‑condensing.

Calibration and Alignment

The transmitter requires periodic calibration to maintain output power accuracy and frequency stability. Calibration is performed using a power meter and frequency counter, adjusting internal potentiometers or via software commands through the control interface. Alignment procedures are detailed in the MDR‑8000 maintenance manual, and the module includes test points for troubleshooting.

Applications

This transmitter is used in point‑to‑point microwave links for telecom backhaul, SCADA systems, and video surveillance networks. Its frequency band is suitable for both licensed and lightly licensed spectrum.

Maintenance and Support

Routine maintenance includes checking the RF connectors for corrosion, verifying the power supply voltage, and monitoring the output power level. Spare modules should be kept for critical links. Replacement is straightforward due to the modular design.

Conclusion

The Alcatel‑Lucent 3EM09626AD RF transmitter offers robust performance and reliability for microwave communication systems, ensuring high‑quality signal transmission in the 2025‑2290 MHz band.