The zero-IF receiver architecture gains popularity in wireless applications because of its suitability to demodulate very wideband RF signals. This capability is important in digital pre-distortion (DPD) transmitters.
Realization of sufficient dynamic range is commonly known to be a major issue of
zero-IF architectures. DC offsets and second-order intermodulation products are both
co-located in frequency with the signal of interest and therewith reduce the receiver sensitivity.
Linear Technology’s new LTC®5584 and LTC5585 I/Q demodulators are capable of demodulating RF signals with more than 500MHz bandwidth, while maintain high receiver dynamic range. This is achieved though the unique capability of these demodulators to minimize DC offset and IM2 products in the baseband outputs through simple adjustment of a DC control voltage.