| 摘要 |
PROBLEM TO BE SOLVED: To generate an orthogonal signal having a strictly 90° phase difference, and to achieve high quality local oscillation light by using that orthogonal signal.SOLUTION: An orthogonal signal generator is constituted of first and second splitters, a multiplier, a loop filter for phase control, and a VCO for generating an orthogonal signal. The first splitter splits a first sinusoidal signal inputted into two, and outputs one of them as a first output signal, and the other as a first phase control signal to the multiplier. The VCO for generating an orthogonal signal generates a second sinusoidal signal, and sends to the second splitter. The second splitter splits the second sinusoidal signal into two, and outputs one of them as a second output signal, and the other as a second phase control signal to the multiplier. The multiplier generates a phase information signal by multiplying the first and second phase control signals, and sends to the loop filter for phase control. The loop filter for phase control sends the phase information signal, while smoothing, to the VCO.SELECTED DRAWING: Figure 2 |
