Foxconn, assembler of Apple's iPad and iPhone, has unveiled plans to upgrade its production capacity in mainland China, expanding the company's existing plant in Henan province, reports said.

The whole expansion plan, according to Apple Insider, will cost the Taiwanese firm some $1 billion and will double the size of its Zhengzhou factory, the site where many gadgets sold around the world are put together.

The planned expansion, Digital Trends said, will make the Zhengzhou facility as the largest smartphone factory in the world once the upgrade has been completed, construction of which will commence in 2012.

Foxconn's Zhengzhou expansion is seen by experts as the company's way of accommodating expected production spike in the run up for the anticipated release of new iPhone and iPad versions next year.

At present, Zhengzhou boasts 95 production lines that according to Digital Trends churn out an estimated 200,000 units of iPhone on a regular working day.

Those numbers are expected to soar dramatically as Apple ramps up efforts to issue new versions of its bestselling gadgets, which experts predicted would be unleashed between the first quarter and third quarter of the coming year.

Foxconn, at the same time, hopes to increase its sales revenue on 2012, aiming to gross more than $20 billion by next year not only on the back of brisk sales by Apple gadgets but also of rival devices.

Apart from Apple, the Taiwanese company also maintains contracts with Microsoft, Sony, Nintendo and Dell to manufacture their products, Digital Trends said.

Foxconn has yet to determine the exact date of when will the added production lines will become operational but it is understood that they will be online just in time for the expected debut of the new iPads and iPhones, also next year.

Fans are expecting the new Apple smartphone to hit the market early 2012 while the iPad should come later in the year, most likely to be manufactured by Foxconn's freshly constructed facilities.