stub impedance

Hi
I design a Single-Stub Impedance Matching circuit operating at 2.6GHz. But the bandwidth is narrow. How can I improve the bandwidth?

Thanks in anticipation!

You might need to apply a resonator composed of short and open shunt stubs. If you have access to ieeexplore, search for keywords: wideband tuning, alfred lopez or wheeler, wideband tuning

If not, let me know and I might be able to upload the article for you.

Thanks for your help. I really want that article. Could you upload it if you have time?