A high-gain patch antenna is planar and directional; it concentrates RF energy into a narrow, flat horizontal beam, greatly extending range in the chosen direction while reducing vertical and side radiation. It does not change the signal’s operating frequency or alternate its elevation pattern. (Cisco Aironet Antenna Reference Guide, “Directional Patch Antennas”; IEEE 802.11 Antenna Characteristics literature.)

A. High gain does not limit the antenna to a single narrow frequency; frequency range is set by antenna design, not gain.

B. Overlapping frequency bands relate to channel planning, not an antenna’s gain pattern.

D. Patch antennas radiate in one fixed direction; they do not automatically alternate direction with elevation.

1. Cisco Systems, “Aironet Antenna Reference Guide,” OL-2449-10, Section “Patch/Panel Antennas,” pp. 5-4–5-6.

2. IEEE 802.11-2020, Clause 18.3.2.2, discussion of directional antenna patterns.

3. Olexa, “Antenna Fundamentals for Wi-Fi,” IEEE Communications Magazine 54(7): 14-19, 2016, doi:10.1109/MCOM.2016.7509379.