results of tunable microstrip antenna

Hi all

i want to know how to find the following parameters for tunable patch antenna ( for example take attached papers)
(1) tuning range
2)size reduction factor as given in abstract of attched papers
3) % bandwith for the resonant frequency
regards
kartik

tuning range is the amount of resonant frequency shift could achieve by changing reactance.

% bw is{ [higher cutt off frequence (Fh) - Lower cutt off frequency (Fl)]/reasonant frequency of patch (Fc)} X100
(the Fh and Fl values are to be taken on return loss plot at -10dB .while Fc is frequency with min. return loss)

Designs for forecasting and are provided, the advantages of using metamaterial substrates are mentioned, and the outcomes in this antenna try things out are provided.