Compact multifunctional antennas for wireless systems

Chapter 6

Solar-Cell-Integrated Antennas

6.1 Integration of Antennas with Solar Cells

A solar cell is also known as a photovoltaic or photoelectric cell. It is a device that converts sunlight into electricity. The photovoltaic effect was found by a French physicist, A. E. Becquerel, in 1839, and the phenomenon was later explained by A. Einstein, in 1905. Materials used for modern photovoltaic cells include monocrystalline and polycrystalline silicon, amorphous silicon, cadmium telluride, copper indium selenide/sulfide, and many others. In the past two decades, some work has been reported on the integration of different antennas with solar cell panels (1, 10). Most solar-cell-integrated antennas were used for space-related applications. Figure 6.1 is a photograph showing a satellite bearing antennas and solar cells on different parts of its body. As can be seen from the figure, the two components usually constitute a large surface area. This is very undesirable, as size and weight are among the scarcest resources on a satellite! In 1995, Tanaka et al. (1) covered the resonator and ground surfaces of a microstrip patch antenna with photovoltaic panels. The solar-cell-loaded microstrip antennas were then used in designing a microsatellite. Later, Vaccaro et al. (2, 3) proposed etching slot antennas on a solar cell panel, at the expense of reducing the effective illumination area. The configuration of Vaccaro's solar-cell-loaded antenna, which is called Solant, is shown in Fig. 6.2 ...