Abstract-A reconfigurable microstrip antenna is proposed for low-cost adaptive beam-switching applications. A small patch-slotring structure is used as the radiating element where an asymmetrical arrangement of p-i-n diodes is employed to switch the pattern in four directions. The antenna provides pattern switching of 65 and 45 in its fundamental mode for the elevation and azimuth planes, respectively. By maintaining the resonant frequency and beamwidth as relatively constant, beam switching is realized using a single feed point.Index Terms-Beam steering, p-i-n diodes, reconfigurable antenna.

A micelle-vesicle transition induced by n-octanol C(8)OH was observed in an aqueous cetyltrimethylammonium bromide (CTAB)/potassium bromide (KBr) system. This transition was investigated by viscosity, rheology, dynamic light scattering (DLS), and direct imaging technique, cryo-transmission electron microscopy (cryo-TEM). Viscometry shows that the system underwent several morphological transitions with the increase in concentration of C(8)OH (regions I-IV). At low octanol concentration (region I), DLS analysis showed an increase in the apparent hydrodynamic diameter of the micelles with the addition of C(8)OH which was supported by cryo-TEM and rheology. With further addition of C(8)OH, transition of the elongated micelles occurred to a viscoelastic fluid comprising entangled wormlike micelles (region II), for which rheological data can be described by the Maxwell model. Further, the wormlike micelles transform to vesicles at [C(8)OH] ≈ 0.020 M (region III). This transition and the consequent changes in the fluid response can be explained in terms of vesicle formation caused by further addition of C(8)OH. Beyond this concentration (region IV), vesicles are the predominant microstructures in the system which shows unusual temperature response.