Analysis of Cellular Antennas for Hearing-Aid Compatible Mobile Phones

The Federal Communications Commission ensures that a certain portion of mobile phones sold in the United States are hearing-aid compatible. When the phone is tested for compatibility, the spatial near-field distribution generated by the phone in the vicinity of its acoustic output is used as the assessment criteria. Certain types of cellular antennas are known partial solutions for the radio-frequency related challenges of hearing-aid compatibility. We briefly summarize the characteristics of these antennas, introducing a new figure-of-merit based on a radiating and balanced mode analysis. We then introduce a class of dual-feed, dual-radiator cellular antennas as promising new candidates for enabling hearing-aid compatibility. It is shown that the proposed antennas, utilized with proper matching circuits, have inherent characteristics that make them attractive solutions for hearing-aid compatible mobile phones.