| 摘要 |
PURPOSE:To adjust a band of an optical reception module to obtain a prescribed level of a reception sensitivity by fine-adjusting a varactor diode being a component of a built-in roll-off filter with a voltage applied externally or a voltage set in the inside of the module. CONSTITUTION:A capacitor being a component of a 5-degree roll-off filter 14 consists of respective series connection of a C2222 and a D2226 and a C2424 and a D2428. The band of the roll-off filter is adjusted by fine-adjusting voltages V2227, V2429 applied to the D2226 and the D2428 and the reception sensitivity of the entire reception circuit is improved. |
