| 摘要 |
PURPOSE: To obtain satisfactory noise characteristic and distortion characteristic without reducing the upper limit value of the transmission frequency and also to stabilize production and supply. CONSTITUTION: In the optical receiver having a photo diode PD as the light reception element, a frequency tuning circuit is formed at the RF output terminal of the photo diode PD by a transformer T having an electrostatic capacitor Cd , a variable capacitor Cx , and a transformer T with inductance L. The RF signal output in the high frequency range of the modulated frequency of light is intensified, and a buffer resistor R is connected in series to its succeeding stage, and it is inputted to a preamplifier A having low input and output impedance. |
