Can you please suggest some of the best suppliers?
That depends, to some extent, on whether you need a passive low-frequency (LF), high-frequency (HF) or ultrahigh-frequency (UHF) reader. Plus, keep in mind that there are many different form factors from which to choose. Some readers are designed for shelves, some for dock doors and others for hanging overhead in retail stores. Without knowing more about what you need, it would be difficult to point you in the right direction. But some of the companies that manufacture passive readers are listed below:
This, of course, is not an exhaustive list—there are many others. These companies are all exhibiting at this week's RFID Journal LIVE! 2014 conference and exhibition, taking place in Orlando, Fla.
—Mark Roberti, Founder and Editor, RFID Journal