Patch Fed Planar Dielectric Slab Extended Hemi-Elliptical Lens Antenna

Abstract

We present the results of a parametric study devised to allow us to optimally design a patch fed planar dielectric slab waveguide extended hemi-elliptical lens antenna. The lens antenna, 1113 in the lens plane and 0 6 thick, constructed from polystyrene and weighing only 90 g is fabricated and characterized at 28.5 GHz for both single and multiple operating configurations. The lens when optimized for single beam operation achieves 18.5 dB measured gain (85% aperture efficiency), 40 and 4.1 half power beamwidth for E plane and H plane respectively and 10%impedance bandwidth for 10 dB return loss. While for optimized for multiple beam operation it is shown that the lens can accommodate up to 9 feeds and that beam symmetry can be maintained over a scan angle of 27 with a gain of 14.9 to 17.7 dB, and first side lobe levels of 11 to 7 dB respectively. Over the frequency range 26 to 30 GHz the lens maintains a worst case return loss of 10 dB and port to port feed isolation of better than 25 dB. Further it is shown that residual leaked energy from the structure is less than 48 dBm at 1 cm, thus making a low profile enclosure possible. We also show that by simultaneous excitation of two adjacent ports we can obtain difference patterns with null depths of up to 36 dB.

Reflector and Lens Antennas

“…Xue and Fusco reported on their development of a planar dielectric slab extended hemi-elliptical lens antenna, which was fed by a microstrip patch [48]. The lens was designed to operate at a center frequency of 28.5 GHz and constructed from a polystyrene sheet (e r ¼ 2:2 and tan d ¼ 0:0005).…”

A New Derivation of the Upper Bounds for the Ratio of Gain to Q

“…Thus the inequality (2) applies. Combining (7) and (2), we obtain max G Q dir = 2k k 2 E = 1 n=1 2(2n + 1) Qn + Q 0 n ; (8) which is [2,Eq. (20)].…”

Millimeter-Wave Elliptical Lens Antenna for Fan-Beam Monopulse Applications

“…In this design, the minor axis of the elliptical lens is chosen to be a = 37.0 mm. The major axis and focal length are then calculated as b = 54.0 mm and c = 39.4 mm, respectively [11]. Two patch antennas, which are located at the back of the lens, are employed as feed antenna to launch a sum beam or a difference beam.…”

“…Dielectric lenses can be hemispherical [7], ellipsoidal [8], or flat-shaped [9]. Various planar feed antennas, such as slot-ring [10] and patch antennas [11], have been successfully utilized for dielectric lenses.…”