Designing less expensive RF wireless transceivers that can operate effectively and efficiently in the crowded wireless spectrum is a major challenge that must be met by today's designers. To reduce silicon costs, the chip dies must be as small as possible. To reduce the cost and size of batteries in mobile wireless devices, the amount of power consumed by the chip must be as little as possible. External components such as filters and their matching components, which are bulky and expensive, must be integrated on the chip to the greatest extent possible.

To address the issue of operating effectively in a crowded wireless spectrum, cognitive radios have been introduced. Cognitive radios are smart devices that can search for any available spectrum (even ones that are outside of what is specified by the standard) and take advantage of that free spectrum. Additionally, over the last decade, researchers have been exploring the possibility of using a universal radio that can be programmed and reconfigured through software to operate on any band, channel bandwidth, and modulation scheme. Such a universal radio is called a software-defined radio (SDR).

For a wireless device to support SDR, it must be capable of broadband operation, which raises a few unique challenges. The receiver of such a broadband device is open to any in-band or out-of-band interferences and must be able to tolerate them while maintaining good sensitivity.