Technologies for Near-Field Focused Microwave Antennas

Figure 2

The −3 dB spot diameter (spot size in the transverse plane at the focal distance) as a function of the array size, , for (see Figure 9 in [2]). The markers denote the performance of NFF arrays described in [4, 7, 8, 12, 15, 16, 20, 22, 33]; the circles and squares are related to simulated and measured results, respectively; for each referenced paper, the empty markers indicate results given by the authors and the filled markers are results extracted from figures. is the focal distance normalized to the radius of the far-field region boundary ().