 
 <prompt> Wetin dem dey observe for di behavior of di material wen dem dey determine di reciprocity property? Given di previous question, write a context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: ```One necessary condition for the reciprocity property wey we talk about be say the materials wey dey inside the antenna and transmission medium dey linear and reciprocal. Reciprocal (or bilateral) mean say the material get the same response to electric current or magnetic field wen e dey go one direction, as e get to the field or current wen e dey go the opposite direction. Most materials wey dem dey use for antennas dey meet these conditions, but some microwave antennas dey use high-tech components like isolators and circulators, wey dey made of nonreciprocal materials like ferrite. Dem fit use these ones give the antenna different behavior when e dey receive pass wetin e dey transmit, wey fit dey useful for applications like radar.``` 