Which array is formed to enable scanning in both azimuth and elevation, providing two-dimensional steering?

Which array is formed to enable scanning in both azimuth and elevation, providing two-dimensional steering?

• A. One-dimensional linear array
• B. Ring array
• C. Two-dimensional planar
• D. Cylindrical array

Answer: (C)

A two-dimensional steering requires a planar array. Placing antenna elements in a rectangular grid on a single plane lets you control the phase (or time delays) in both horizontal (x) and vertical (y) directions. By adjusting those two sets of phase shifts, the main beam can be directed toward any combination of azimuth and elevation, giving true scanning in both dimensions. Other arrays are limited by their geometry: a one-dimensional linear array can steer mainly in azimuth (in the plane perpendicular to the line), a ring array largely covers azimuth around the ring, and a cylindrical array primarily provides azimuth coverage with less straightforward elevation control. The planar layout is the straightforward way to achieve two-dimensional beam steering.

A two-dimensional steering requires a planar array. Placing antenna elements in a rectangular grid on a single plane lets you control the phase (or time delays) in both horizontal (x) and vertical (y) directions. By adjusting those two sets of phase shifts, the main beam can be directed toward any combination of azimuth and elevation, giving true scanning in both dimensions.

Other arrays are limited by their geometry: a one-dimensional linear array can steer mainly in azimuth (in the plane perpendicular to the line), a ring array largely covers azimuth around the ring, and a cylindrical array primarily provides azimuth coverage with less straightforward elevation control. The planar layout is the straightforward way to achieve two-dimensional beam steering.