Wideband radial line slot array antenna

An antenna comprising:

• a waveguide configured to transmit a transmit-beam of radiation and receive a receive-beam of radiation, the waveguide comprising:
• a backplane comprising radial support ribs;
• a feed pin comprising a teardrop shape and disposed at a center of the backplane and configured to interact with a wave of radiation;
• a foam spacer disposed on the backplane, wherein an effective refractive index of the waveguide with the foam spacer is greater than approximately 1.0 and less than approximately 1.5;
• a facesheet disposed on the foam spacer and opposite to the backplane 104 to allow the wave of radiation to propagate between the backplane and the facesheet and through the foam spacer, the facesheet comprising:
• thermal paint disposed on an outward-facing side of the facesheet;
• and
• pairs of through-hole slots configured to release portions of the wave of radiation to generate the transmit-beam or to receive the receive-beam to generate the wave of radiation, wherein the pairs are disposed as a spiral array about a center of the facesheet and each of the pairs comprises:
• a first slot having a length and a width;
• and
• a second slot having a length and a width, wherein the length of the second slot is oriented approximately perpendicular to a length of the first slot,
• wherein dispositions of the pairs of through-hole slots are set by a computer process using spline interpolation of parameters of the antenna and are configured to optimize or maximize trade-off between transmit and receive gains associated with the transmit-beam and receive-beam.