 
 <prompt> Which one of di following no dey use to calculate di standing wave ratio: maximum power, impedance or minimum power? Based on di previous question, write a context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: ```As electro-magnetic wave dey waka through different parts of antenna system (radio, feed line, antenna, free space), e fit jam impedance differences (E/H, V/I, etc.). For each interface wey e reach, based on how the impedance match dey, some part of the wave energy fit bounce back to the source, come form standing wave for the feed line. The ratio of maximum power to minimum power for the wave fit be measured and e dey called standing wave ratio (SWR). SWR of 1:1 na ideal. SWR of 1.5:1 dey okay small for low power applications where power loss dey important, although SWR as high as 6:1 still fit work with the right equipment. To reduce SWR and make power transfer pass through each part of the antenna system well well, e dey important to minimize impedance differences for each interface (impedance matching).``` 