Steerable phased array antenna

A system comprising:

• a steerable phased array antenna and a controller therefor, wherein the steerable phased array antenna comprises:
• a plurality of antenna elements disposed in a predetermined number of rows, M, and a predetermined number of columns, N, wherein M and N are positive integers;
• a M number of first beamformer components comprising phase tapers, wherein each first beamformer component corresponds to a row of antenna elements, and wherein each first beamformer component is operatively connected to the N number of antenna elements in the corresponding row;
• and
• a N number of second beamformer components comprising phase tapers, wherein each second beamformer component corresponds to a column of antenna elements, and wherein each second beamformer component is operatively connected to the M number of antenna elements in the corresponding column,
• wherein each of the antenna elements comprise:
• a plurality of combiners each having a first input, a second input, and an output, wherein each input being operatively connected to a corresponding beamformer component and configured to combine a first phase tapered RF signal from the first beamformer component corresponding to a row of a corresponding antenna element with a second phase tapered RF signal from the second beamformer component corresponding to a column of a corresponding antenna element;
• a variable gain amplifier to adjust the amplitude of an RF signal;
• an antenna radiating element for radiating the RF signal into free space;
• and
• a phase corrector to add a π radian phase delay to the output from a combiner when cos(ωt+(mα+nβ)) and (cos(ωt+2 mα)+cos(ωt+2β)) are substantially 180 degrees out of phase with each other, wherein t is time variance and ω is the frequency of the RF signal, wherein a phase taper applied to the first beamformer component is 2×mα, wherein the phase taper applied to the second beamformer component is 2×nβ;
• m is the row number of a corresponding antenna element ≥1 and ≤M;
• n is the column number of the corresponding antenna element ≥1 and ≤N;
• α=K dx sin(θ)cos(φ), K=2π/λ, λ is wavelength of the RF signal;
• dx is antenna element spacing in the row direction;
• dy is antenna element spacing in the column direction;
• and (θ, φ) is the spherical coordinate pointing angle of the steerable phased array antenna,
• wherein the controller, being responsive to commands to steer the steerable phased array antenna, receives the pointing angle (θ, φ) and generates phase taper values to be applied to the first and second beamformer components.

In an electronically steerable phased array antenna comprising rows and columns of antenna elements and RF signal paths connected thereto, a method comprising:

• receiving a predetermined pointing angle (θ, φ) to steer the steerable phased array antenna;
• generating first and second phase taper values for each of M rows and N columns of antenna elements comprising the steerable phased array antenna corresponding to the predetermined pointing angle (θ, φ), wherein M and N are positive integers;
• applying the phase tapers to signals corresponding to each of the M rows and N columns of antenna elements;
• combining phase tapered signals at each corresponding antenna element;
• adjusting a phase of the combined phase tapered signals upon the occurrence of the predetermined condition that cos(ωt+(mα+nβ)) and (cos(ωt+2mα)+cos(ωt+2nβ)) are substantially 180 degrees out of phase with each other, wherein t is time variance and ω is RF signal frequency;
• and
• adjusting a gain of the combined phase tapered signals to equalize an amplitude of output signals of all the antenna elements.