Optical modules OM-R, OM-T, OM-RT
* The output level of an optical receiver is commensurable with the one of a trunk amplifier
An optical transceiver OM-RT consists of a forward channel receiver module (1310nm, 1550nm) and a reverse channel transmitter module (1310nm). The receiver module transforms optical signals in the level range of -3...+2dB/mW into TV range electrical signal (47(84)-862MHz) for a further amplification and distribution in CATV baseline networks. SNR in a TV channel at the optical receiver output (when having input optical signal with the level of 0dBm) provided by the parameters of a receiving/transmitting path (OMS-T + OM-R)≥53dB when the quantity of transferred channels is 50. A terminal stage of a radio frequency part of the node is constructed according to the GaAs-technology and tolerates the output signal level according to DIN 45004 of 125dB/µV. In the standard parts kitting there are two RF outputs in the node. In this case the output signal power is divided by a symmetrical divider. The level at each output decreases by 4dB. Amplitude frequency characteristic unevenness is within a ±1dB limit over the whole band. Availability of the main attenuator of 18dB enables setting the necessary signal level in a cable network. The transmitter module effects reverse channel signal transformation into an optical range with the help of a Fabry-Perot laser with the output power of 0...3dBm (there is a reverse channel filter of 5-65MHz, an equalizer and an attenuator). The signal at the transmitter input from 58 to 94dB/µV in the attenuator position of 0dB is transformed into optical signal. It is transformed back into electrical signal with the SNR of not less than 27dB. The signal with the output level of less than 94dB/µV can be decreased with the help of a tunable attenuator of 0...-20dB. The laser operates in the optical window of 1310nm. The node is equipped with two tapoffs with F-type connectors with a 30dB attenuation to measure signal levels in a forward channel and in a reverse channel. All the RF tapoffs are equipped with the connectors of 5/8" type. All the optical connectors are equipped with SC/APC connectors.
Two LEDs on the front face of the optical node display optical signal availability at the input and at the output respectively.
Mains supply of the node is effected locally from an ac mains of 170...250V and/or distantly from a remote ac source of 25-60V.
An optical receiver OM-R consists only of a receiver module features of which are analogous to the OM-RT receiver module. An optical receiver OM-T consists only of a receiver module features of which are analogous to the OM-RT receiver module.