Design of narrow-width Fermi antenna with circular radiation pattern

The design of the Fermi antenna as a receiving element of PMMW imaging is presented. Using the FDTD analysis, it has been found that the beamwidth of the E-plane and the H-plane of the Fermi antenna can be controlled by changing the width of the aperture and the position of the inflection point of the Fermi-Dirac taper profile respectively. Using these characteristics, a Fermi antenna with circular radiation pattern having a beamwidth of 52/spl deg/ and geometrical width of 0.58/spl lambda//sub 0/ which fits to the f/D=1 optics have been obtained.