Compact-same-size 52- and 156 Mb/s SDH optical transceiver modules

Four types of compact SDH optical transceiver modules for intra- and interoffice transmission systems operating at 51.84- and 155.52-Mb/s have been incorporated with two types of packages, which are the same size for both bit rates. These modules contain both a transmitter and a receiver with a clock recovery function integrated in a single package. They were realized in the same size of L:50 mm×W:25 mm×H:8 mm (volume:10 cm³) and L:81 mm×W:31 mm×H:8 mm (volume:20-cm³) for intra- and interoffice system applications, respectively. The following technologies were used in their development: 1) three kinds of custom IC´s were implemented using a 2-μm Si bipolar process, 2) surface-mounted SAW filters with the same size for both bit rates, and 3) high-density packaging technology to minimize receiver sensitivity degradation due to crosstalk noises. As a result, high receiver sensitivity of -43.2 and -42.7 dBm was achieved for 51.84-/s and 155.52-Mb/s interoffice transceiver modules with a wide dynamic range of over 30 dB. Also, in transceiver modules for intraoffice system applications, a receiver sensitivity of -37.7 and -31.7 dBm were obtained for both bit rates