ake it easier to add new bands for example, and it can be easier to add bands with more discrete solutions. It is certainly easier and cheaper to fix mistakes in less highly integrated designs. As integration levels increase, the number of RF components reduces, the RF bill of materials (RF BOM) goes down and production costs go down. However, moving to a higher level of integration implies an increase in nonrecurring engineering costs. The cost of design mistakes becomes higher. An increase in nonrecurring RF engineering and design costs also implies that higher market volumes are needed to achieve RF economies of scale. NRE costs can be reduced by adopting lower levels of device integration but the RF BOM will increase and the form factor of the phone will increase. RF performance may or may not decrease but will be more variable from phone to phone (handset to handset, batch to batch variations from the production line). Although handsets are becoming more integrated over time, the practical implementation of a single-chip software-definable phone remains elusive. It is relatively easy to count at least 100 separate components in a phone, including modules that themselves contain multiple 1 http://www.rttonline.com/resources.html Telecommunications Economies of Scale functions on separate parts of a common substrate. About 75% of these components in present cellular phones are passive, inductors, capacitors and filters. These devices are frequency specific. Supporting additional frequencies in a handset implies an increase in the number of passive components. This implies higher material and manufacturing costs. Active devices such as the power amplifier can be designed to cover relatively wide frequency bands but become harder to match and lose overall efficiency. Nonstandard frequency allocations therefore have an impact on passive and active device requirements. New MEMS (microelectrical mechanical system) -based technologies offer the potential opportunity to integrate many of these functions onto an RFIC,