Basic question: Quarterwave transformer

hi,

how does the Quarterwave(lambda/4) transmission line acts as a matching transformer between Source and load impedance?

why not half wave transmission line?

thanking in advance

Try here for an animated smith chart explanation

http://www.amanogawa.com/archive/Qua...rLambda-2.html

Another useful site is
http://www.microwaves101.com/encyclo...uarterwave.cfm

A half wave will not work because you do not change the impedance at the end of the line. You go round the Smith chart once and arrive back where you started.