return Return Path Transmitter these wide changes in drive without clipping. The change in signal level that a transmitter can tolerate is known as the dynamic range. The RPT 3105-BTN achieves a dynamic range of 15 dB, more than sufficient for most applications. Also, the Fabry-Perot lasers used in other transmitters are very noisy when not modulated. Transmitters using these lasers must always modulate the laser with a carrier, which greatly decreases the dynamic range. The DFB laser used in the RPT 3105-BTN maintains nearly the same low noise even when not modulated. This is important in the return path, where burst data is common. Advantages " " " Product Description Harmonic's RPT 3105-BTN return transmitter addresses the need for a high-performance transmitter for the General Instrument BTN and Mini Bridger optical nodes. The transmitter is based on an uncooled Distributed Feedback (DFB) laser. This laser has much lower noise and better distortions than the Fabry-Perot laser used in other transmitters for these nodes. " Applications The RPT 3105-BTN has outstanding video and data performance. It contains a unique thermal compensation circuit which maintains high performance over the entire operating temperature range. As the return environment becomes noisy, and the noise level varies dramatically, the laser in a return transmitter must be able to handle Standard Configuration Plug-in pad Fixed Pad DFB laser 32 xfmr Clamp 32 OMI temp comp. OMI adj. Optical power control Analog monitoring and control section 24 VDC Optical out 0 dBm(o) (19% OMI) or +3 dBm(o)(10% OMI) Linear Regulator 7 VDC Laser power select [0 or +3 dBm(o)] Optical power test point (1 V/mW) Optical power monitor point (1 V/mW) LED (GRN-OK RED-Low Opt. Pwr OFF-Power OFF) " " " " Pay-per-view Network management communications Telephony Internet data path The transmitter features a novel optical power circuit which allows the output power to be set to either 2 mW (+3 dBm) or 1 mW (0 dBm). This allows a single transmitter to be used for both longer and shorter optical links. RF Input (35 dBmV) High performance, uncooled DFB laser. High dynamic range for immunity to ingress. User-selectable to either 2 mW (+3 dBm) or 1 mW (0 dBm) optical output allows optimizing optical power for a wide range of optical links. Stabilized to maintain performance over the operating temperature range. RPT 3105-BTN + RPT 3105-MBR HL 3000 Series RPT 3105-BTN + 3105-MBR Preliminar y Specifications Optical Output Noise Power Ratio* Laser type: Uncooled, isolated DFB laser Output power: +3 or 0 dBm (optical) (user-selectable via jumper) Tracking error: 1 dB(optical) Connector type: RPT 3105-BTN-US: SC/UPC RPT 3105-BTN-AS: SC/APC RPT 3105-MBR-AF: FC/APC Wavelength: 1280-1350 nm 45 40 35 S/(N+I), dB preliminary Harmonic Inc. 549 Baltic Way Sunnyvale, CA 94089 Tel. 408-542-2639 Tel. 800-730-4099 Fax 408-542-2510 30 25 20 User Inter face 15 10 -60 -55 -50 -45 -40 -35 -30 -25 -20 RF Input, dBmV/ Hz * 8 dB Optical Link, 40 MHz Data Loading. Laser output power test point: 1 V/mW Green LED: Power on Red LED: Laser power low <0.5 mW Element Management System - NETWatchTM/HEM Parameters available for monitoring: Laser output level Link Per formance CNR1: 49 dB IMD21: -52 dBc IMD31: -57 dBc RF Input Operational bandwidth: 5-65 MHz Frequency response: 1.5 dB (elec.) (peak-to-valley, 5-65 MHz) RF input return loss: 18 dB RF attenuator: 0 to 10 dB in 1 dB steps Impedance: 75 Connector type: Type "F" connectorized pigtail Analog: Nominal RF input into the module for 10% OMI at +3 dBm (optical) output: 35 dBmV (plug-in pad set to 9 dB) Nominal RF input into the module for 19% OMI at 0 dBm (optical) output: 35 dBmV (plug-in pad set to 9 dB) Digital: Nominal input RF power spectral density for C/(N+I) = 40 dB2: -45 dBmV/Hz Input RF dynamic range for C/(N+I) = 40 dB2: 14 dB Copyright 1999 Harmonic Inc. Harmonic continues to improve and enhance all product designs. Specifications are subject to change without notice. Harmonic and logo design, eXchange, MAXLink, METROLink, NETWatch, PWRBlazer, TRANsend, and "Redefining the Network" are trademarks of Harmonic Inc. YAGLink and PWRLink are registered trademarks of Harmonic Inc. All other names are trademarks or registered trademarks of their respective owners. Power Requirements Power supplied by node in which the transmitter is mounted Supply voltage: +24 VDC DC current draw 3: 0.2 A (max.) Environmental Node internal temperature: -40 to 85 C/-40 to 185 F Storage temperature: -40 to 85 C/-40 to 185 F Physical Dimensions: 5.5" L x 1.2" W x 1.2" H 14.0 cm L x 3.0 cm W x 3.0 cm H Weight: 5 oz./0.14 kg Mounting: Within General Instrument's BTN or MiniBridger nodes. Notes: 1. Over the full temperature range; for 10-dB fiber loss and 10% OMI at +3 dBm (optical) output; 4 MHz bandwidth) 2. At +3 dBm (optical) output; 5-45 MHz noise loading; 7 dBm (optical) fiber loss; at input to the module 3. At 24 VDC; over full temperature range 2322-03 2.5K 9/99