Fabry-perot cavity antenna system having a frequency selective surface

A method comprising:

• configuring an antenna system to operate in a first mode, wherein the first mode comprises one of a beam-splitting mode or a beam-focusing mode, and wherein the antenna system comprises:
• a source antenna:
• a frequency selective surface (FSS) having a first side and a second side opposite from the first side, wherein the first side of the FSS includes a plurality of horizontally oriented unit cells, wherein the horizontally oriented unit cells are positioned as multiple columns of unit cells on the first side of the FSS, wherein the first side of the FSS faces the source antenna, and wherein the first side of the FSS is separated from the source antenna by a defined distance;
• and
• a housing that includes a fluidic channel, wherein the housing is positioned on the second side of the FSS, wherein the fluidic channel includes one of air or deionized water, and wherein the fluidic channel is positioned on a portion of the second side of the FSS that is opposite to a subset of the horizontally oriented unit cells on the first side of the FSS;
• and
• subsequent to the antenna system operating in the first mode for a duration of time, reconfiguring the antenna system to operate in a second mode, wherein the second mode comprises one of the beam-splitting mode or the beam-focusing mode, wherein the second mode is different from the first mode, and
• wherein configuring the antenna system to operate in the first mode and reconfiguring the antenna system to operate in the second mode each comprise filling the fluidic channel of the housing with one of air or deionized water.

An antenna system, comprising:

• a transmit antenna that is configured to emit radiation:
• a frequency selective surface (FSS) having a first side and a second side opposite from the first side, wherein the first side of the FSS faces the transmit antenna and includes a plurality of horizontally oriented unit cells, wherein the first side of the FSS is separated from the transmit antenna by a first defined distance, wherein at least a portion of the radiation emitted by the transmit antenna passes through the plurality of horizontally oriented unit cells, and wherein the plurality of horizontally oriented unit cells includes one or more groups of cells that each includes multiple columns of one or more horizontally oriented unit cells;
• a receive antenna that is configured to receive at least the portion of the radiation that passes through the plurality of horizontally oriented unit cells of the FSS, wherein the receive antenna faces the second side of the FSS and is separated from the second side of the FSS by a second defined distance, and wherein the FSS is positioned between the transmit antenna and the receive antenna;
• and
• an enclosure that is configured to at least partially enclose the transmit antenna, the FSS, and the receive antenna.