A Simple Reconfigurable Antenna

摘要

When a semiconductor is irradiated with light or electrons of sufficient energy, the irradiated part will become conducting. This well-known mechanism can be used to create antennas with conducting parts controlled by the irradiating source, and structures reconfigurable by changing the irradiation patterns. We have analyzed the practicality of this method of antenna reconfiguration, and come to the conclusion that for whole-area reconfigurable antennas (all of whose conducting parts are irradiated), the most practical method is with an incoherent optical source. In this paper, we will present both our analysis, and our experiment on a simple reconfigurable antenna which is summarized below.rnA simple reconfigurable is illustrated in Fig. 1. A camera flash, whose output light energy was measured to be about 1 joule, illuminated a 4"-diameter, undoped silicon wafer through a mask which transmitted a bow-tie pattern. The illuminated pattern on the silicon served as the antenna and was connected through a transmission line to a signal source. On a second silicon wafer, gold was deposited to create the same bow-tie pattern which serves as the receiving antenna and was connected to a spectrum analyzer. A continuous signal from 1 GHz to 3 GHz was fed to the transmitting antenna, and the signal levels received by the reconfigurable antenna were recorded (Fig. 1) . The reconfigurable antenna then was replaced with a third antenna which was identical to the receiving, metallic antenna. The measurements were repeated. The efficiency of the reconfigurable antenna relative to the metallic antenna was determined by the relative signal levels received by the two antennas.