Phased Array Antennas
Phased array antennas are one of the easiest ways to achieve beamforming
and beam-steering. A phased array antenna can be understood using the
analogy of an N -slit diffraction experiment where the overall
beam from the array is a result of coherent constructive interference ofN sources (or independent antenna elements in an array). Each
antenna element in the array is fed with a phase shift, introducing a
time delay in the radiated beam. The constructive interference of these
time-delayed beams from each radiating element enables directional
control. A simple representation of the beam tilt because of the phase
shift in different elements using an array of six open-ended waveguides
is shown in Figure 3. The radiation pattern and tilt angle for such
antennas can be estimated using the array factor. Detailed mathematics
for the calculation of tilt angle is provided within the Supplementary
Information.