Circular Polarizer Function A circular polarizer converts an incident linearly polarized wave into a circularly polarized wave (of appropriate handedness) when aligned and tuned correctly. True or False?

Introduction / Context:
Polarization control is crucial in satellite links, radar, and instrumentation. A circular polarizer is a network (waveplate, septum, or multilayer structure) that changes the polarization state of an electromagnetic wave.

Given Data / Assumptions:

• Incident field is linearly polarized at the required 45° orientation to the polarizer axes.
• Device is designed for a frequency band of interest.

Concept / Approach:

A circular polarizer imposes a 90° phase shift between two orthogonal linear components of equal amplitude. When the input is linearly polarized at 45° to those axes, the outputs in the two eigen-axes are equal in magnitude; the quarter-wave phase delay converts the field into circular polarization (left- or right-hand depending on orientation and sign of the phase shift).

Step-by-Step Solution:

Verification / Alternative check:

Stokes parameter analysis shows the output has normalized parameters consistent with circular polarization (Q ≈ 0, U ≈ 0, V ≈ ±1).

Why Other Options Are Wrong:

“False” contradicts the operating principle. Real devices have finite bandwidth, not zero bandwidth, and exist for waveguide and free-space implementations.

Common Pitfalls:

Feeding at 0° or 90° instead of 45°, leading to ellipticity or no conversion; ignoring bandwidth and tolerance limits.

Final Answer:

True