| 摘要 |
A device comprises a multiplication circuit configured to derive a product of a first signal S1 and a second signal S2, S2 having a phase difference β relative to the first signal S1, a low pass filter configured to remove a selected frequency component from the product of S1 and S2 to derive a dot product S1·S2; and a calculation circuit configured to receive the dot product S1·S2 and generate a signal output having a ratio |S1|/|S2| and the phase difference β. |
