Absfracf-The radiation properties of a spherical phased-array antenna with circularly polarized elements are studied. Each antenna element is assumed to have a cosine @pe of field pattern. It is found that such an array is capable of providing complete hemispherical coverage without appreciable loss of gain. The radiation produced by the array stays circularly polarized in all directions, and the state of polarization is independent of beam steering. A special distribution of elements on a spherical surface is developed. This considerably suppresses the grating lobes in the pattern and thereby makes the antenna array broadband. Numerical calculations are made to determine the directivity and halfpower beamwidth for the radiation patterns produced under various situations.

Three separate laser modalities were investigated in the treatment of superficial varicosities/telangiectasias of the lower extremities. Sixteen patients were treated and followed for 12 months. The superpulse CO2, the pulsed focally specific CO2, and the Nd:YAG laser transmitted through a diffusing sapphire tip were able to produce cosmetically satisfactory permanent obliteration of vessels after a 12-month follow-up interval. These results were a significant improvement over six-month results indicating a long fading time for laser treatment of leg veins.

Thirty-four patients with 57 cutaneous lesions have been treated with the Nd:YAG laser under an experimental protocol over a year of study. The majority of treatments were done on an outpatient basis under local anesthesia. Capillary/cavernous hemangiomas of the oral cavity responded well, but hemangiomas of infancy responded poorly. Hypertrophic scars and keloids responded well only in conjunction with steroid treatment. Epistaxis in patients with hereditary hemorrhagic telangiectasia responded well for 4-5 months and then recurred. Areas with thin skin or mucosa have the potential for full-thickness injury with complications of scar, bony exposure, or septal perforation.

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