so I have a question regarding reflections/characteristic impedance and there relation with a quarter wave transformer and its feed line.
Now I have found this video very useful for visualising what is happening with standing waves https://www.youtube.com/watch?v=M1PgCOTDjvI&t=70s coupled with the the recommended wiki link from this video. https://en.wikipedia.org/wiki/Standing_wave_ratio
I have two questions which can be applied to the following picture 1. For a quarter wave transformer it is (relatively) easy to calculate the length of the quarter wave transformer to allow for the voltage or current to be at their maximum or minimum, BUT what happens if the length of the feedline to this quarter wavelength transformer starts with the RF wave being not at a perfect division of the wave, e.g. 1/4, 1/2, 3/4 ? Does the length of the feedline to the quarter wave length transformer need to be a certain length too?
- Slightly related but if I am feeding a dipole antenna, do I similarly need to make sure that the feed line length is the correct length to allow for the current distribution to be at the correct points be nulls by adjusting the FEEDLINE LENGTH?
Another example from http://colinkarpfinger.com/blog/2010/the-dropouts-guide-to-antenna-design/ - surely the length of the feeline should be specified for antenna design or am I missing something about it not effecting design if it is under a certain length.