-
An all pass network imparts only—
-
- negative phase to the input
- positive phase to the input
- ± 90º phase shift to the input
- ± 180º phase shift to the input
- negative phase to the input
Correct Option: D
Transfer function of an all pass network,
= 1 – s 1 + s = 1 – jω 1 + jω, ∠ φ = tan– 1 (ω) – tan– 1 ω
As ω → ∞, ∠ φ → – 180°
However, if the transfer function
| = | = | ||
| 1 + s | 1 – jω |
∠ φ = tan–1 ω – tan–1 (– ω) = 2 tan–1 ω,
as ω → ∞, ∠ φ → + 180°.
Thus, an all pass transfer function impart ± 180° phase shift to the input. Hence alternative .
