San Diego-based Qualcomm said this morning that it is in a definitive agreement to buy Atheros Communications, in a deal worth $3.1 billion. Qualcomm said it would pay $45 per share in cash for Atheros, in an effort to accelerate the expansion of its technologies and platforms beyond the cellular market. Atheros is a developer of products for the wireless and wired local area network communications market. Qualcomm said the Atheros provides it access to "significant new growth opportunities."