What's the correct form of use the real coded genetic algorithm?

I'm new to genetic algorithms, but I haven't found specific info about real-coded GA's. I want to do antenna array optimization by using the real values of antenna position, phase, and amplitude, but I've only found binary encodings. Although the binary encodings seem easier during crossover, but I would like to use real continuous values, but I don't know how to apply crossover.

In MATLAB, I've been using an error value as a fitness function obtaining a vector with all the error data and using this to select the new population. I'd also appreciate a source describing the real continuous encoding process.