Apple Insider reports that Apple is expected by one Wall Street analyst to announce a completely redesigned "iPhone 5," with a new unibody aluminum design, as well as a low-end "iPhone 4S," geared toward the midrange smartphone market, in the coming weeks.

The two anticipated new iPhone models are expected by analyst Chris Whitmore with Deutsche Bank to push Apple's smartphone sales even higher. He sees the so-called "iPhone 4S" as a handset with a bill-of-material cost lower than $150, allowing Apple to sell it for between $300 and $350 without a carrier subsidy.

Whitmore sees a low-cost iPhone giving Apple even greater market penetration into the midrange smartphone market, where he estimates there are about 1 billion prepaid customers. Such a move would "drastically expand" the addressable smartphone market for Apple, he believes.

  Aluminum unibody iPhone 5, low-cost iPhone 4S seen propelling Apple's sales