Abstract: Autonomous communications systems often involve the use of separate solar cells and antennas, which necessitate a compromise in the utilization of the limited surface area available. These separate items may be combined,, provided that the antennas and solar cells are compatible. To show the compatibility of solar cells and antennas, the concept is used to create linearly polarized slot antenna, a circularly polarized shot antenna, a circularly polarized slot antenna and a slot array. The concept offers advantages in terms of surface coverage, volume, weight and electric performance. Slot antennas provide large metallic surfaces (the ground plane) on which solar cells can be directly grown. This yields high area coverage efficiency for the solar cells. In this, it is possible to nearly completely cover the ground plane with exception of a very small area close to the radiating edges of the slot antenna without degradation of the RF performance.