Electromagnetic compatibility of wireless devices a preliminary investigation

The objective of this investigation is to demonstrate the importance of a thorough electromagnetic compatibility (EMC) analysis of wireless devices operating in complex and uncontrolled electromagnetic environments. A fundamental requirement for the successful deployment of a wireless service is that it should neither suffer interference (based on immunity of the wireless device) from, nor cause interference (emission from the device) to, other electrical products when operated near by. The immunity of the wireless device is determined by estimating the receiving noise level of a typical handset operating dose to another electrical device. Emission from a wireless device is estimated by modeling the antenna and handset body using the Numerical Electromagnetic Code (NEC). Preliminary analyses show that under the present FCC emissions limit (FCC part 15.109), a handset may suffer interference when operated close to electrical devices "leaking" radiated emissions. The analyses also concluded that a handset radiating at a power of 250 mW may affect the operation of nearby electrical equipment if the equipment does not have significant radiation immunity per ANSI C63 guidelines. Therefore, it is highly recommended that the above EMC issues be studied in detail to quantify the effects.