In January, PC maker Lenovo announced it would expand its mobile efforts with the proposed acquisition of Google’s Motorola Mobility for $2.9 billion. Now the Chinese company plans to spend $100 million on patents related to 3G and 4G tech from U.S.-based Unwired Planet. Already one of the biggest smartphone vendors in China, Lenovo plans to use the 21 patent families from Unwired Planet to grow its smartphone and mobile business in new markets.

“In addition, Unwired Planet is licensing its patent portfolio to Lenovo for an unspecified number of years,” reports CIO.com. “The Nevada-based company develops mobile technologies in use by carriers including AT&T and Sprint. After its deal with Lenovo closes, Unwired Planet said it will have about 2,500 issued and pending international patents in its portfolio.”

With the proposed Motorola Mobility deal with Google, Lenovo will be able to enter the North American market. The company reportedly plans to keep Motorola Mobility intact.

“The Motorola deal will also help the Chinese company shield itself from patent-related lawsuits that have been used to try to stymie the businesses of other handset makers,” notes the post. “By buying Motorola, Lenovo will take ownership of over 2,000 patent assets and also gain access to Google’s own patent portfolio.”