Tag antennas may be packed in close to one another on a shelf, in a crate, on a truck etc. This creates coupling effects that in turn affect the antenna gain, radiation pattern and polarization properties, and may reduce antenna performance. 

Some common concerns when designing an RFID antenna are antenna type, impedance, and RF performance when embedded to another object, or when there are other adjacent structures. RFID antenna designers must make sure that they maximize the transfer of power into and out of the device while embedded on the protected object. They also need to take the size and the shape of the readout antenna, the orientation of the transponder, and the other surrounding electronics into consideration as they impact antenna pattern.

RFxpert quickly measures the performance of an antenna design with far-field pattern data and radiated power levels. It also provides immediate insight into the root causes of performance challenges by visualizing resonances and surface currents. With the Circular Polarization (CP) option, the RFxpert calculates the right and left hand circularly polarized patterns and displays axial ratio patterns. RFxpert provides real-time assessment of the impact of design changes or component and packaging modifications right from your bench.