Smith chart plot from simulation is opposite from experiment?
Always refer to clock for increasing frequency and for standing wave impedances on simple antennae , it should be clockwise increasing f  over the band of interest.

So it is showing as it should with many standing wave resonance points closest to the centre thru an octave in frequency.   

Except your impedance is mismatched and circling around and only achieves perfect Gamma=1 near 0.7GHz.  

(for a real measurement), this assumes your cables are calibrated with a fixed R to give a perfect dot at center, which may not be true if using cheap coax instead of semi-rigid copper tubing for the test.