A singlestub tuner see figure below is applied to match a lo

A single-stub tuner (see figure below) is applied to match a load, composed of R_load - 200 ohms and L = 79.6 nH, to a 100 ohm transmission line. The frequency of circuit operation is 300 MHz. Assume open space conditions (e relative = 1).

Solution

1) Convert the load to a normalized admittance: yL=g+jb

2) Transform yL along constant towards generator until yA = 1 + jbA

– This matches the network’s conductance to that of the transmission line and determines dstub.

3) Find ystub = -jbA on Smith Chart

4) Transform ySTUB along constant towards load until we reach PSC (for short-circuit stub) or POC (for open-circuit stub)

– This cancels susceptance from (2) and determines LSTUB.