IQE, the producer of silicon wafers for electrical products, expects a revenue increase of 20% in dollar terms in 2011, although the actual increase has been affected by currency exchange rates.The group forecasts first half revenues of £38m and earnings before interest, tax, depreciation and amortisation (EBITDA) of £6m.Dr Drew Nelson, IQE's chief executive, said:"The continued growth in demand for our wireless products and accelerated growth for our optoelectronic wafers have enabled us to maintain our rapid growth."IQE shares were down 0.6% in afternoon trading.BS