Question E9B05:
What type of antenna pattern is shown in Figure E9-2?  

Choices:  
A: Elevation  
B: Azimuth  
C: Near field  
D: Polarization    

Correct Answer is  A: Elevation  

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The figure shows a vertical-plane cut of the antenna’s radiation—signal strength vs. elevation angle above the horizon—so it is an elevation pattern.

Why A (Elevation) is correct:
- An elevation pattern plots gain vs. elevation angle $\theta$ (0° at the horizon, 90° overhead) for a fixed azimuth direction.
- It is used to read the main takeoff angle (the elevation angle of maximum radiation) and see high/low-angle lobes.

Why the other choices are incorrect:
- B: Azimuth — An azimuth pattern is a horizontal-plane cut, viewed from above, showing gain vs. compass direction (angle $\phi$ from 0° to 360°) at a fixed elevation. It does not have 0°–90° vertical angle scales.
- C: Near field — “Near field” describes a region around the antenna, not a type of far-field pattern plot. Exam figures show far-field radiation patterns.
- D: Polarization — Polarization (horizontal, vertical, circular) is the E-field orientation, not a radiation pattern plot.

Useful relationships and rules of thumb:
- Full 3D pattern is $G(\theta,\phi)$.
  - Elevation cut: $G(\theta,\phi_0)$ (fixed azimuth).
  - Azimuth cut: $G(\theta_0,\phi)$ (fixed elevation, often near the horizon).
- Takeoff angle (TOA): the elevation angle of the main lobe peak.
  - Horizontal antennas: as height increases (measured in wavelengths), TOA generally decreases and multiple elevation lobes appear.
  - Verticals: typically favor low elevation angles (good for DX).

This is why the figure labeled with angles from the horizon upward corresponds to an elevation pattern.