 problem described above and related cost and implementation issues. RF Component Innovation 5.5.1 RF MEMS The application of radio-frequency microelectromechanical system microscale devices is being expanded to include MEMS switches, resonators, oscillators and tuneable capacitors and (in the longer term) inductors that potentially provide the basis for tuneable filters. RF MEMS are not a technical panacea and as with all physical devices have performance boundaries, particularly when used as filters. If any device is designed to tune over a large frequency range it will generally deliver a lower Q (and larger losses) than a device optimised for a narrow frequency band. An alternative approach is to exploit the inherent smallness of RF MEMS devices to package together multiple components, for example packaging multiple digital capacitors on one die. The purpose of these devices to date has been to produce adaptive matching to changing capacitance conditions within a band rather than to tune over extended multiband frequency ranges. In an ideal world additional switch paths would be avoided. They create loss and distortion and dissipate power. More bands and additional modes therefore add direct costs in terms of component costs and indirect costs in terms of a loss of sensitivity on the receive path and a loss of transmitted power on the transmit path. MEMS (microelectrical mechanical system) -based switches help to mitigate these effects. There is also a potential power handling and temperature cycling issue. The high voltages implicit in the GSM TX path can lead to the dielectric breakdown of small structures, a problem that occurred with early generations of SAW filters. Because MEMS devices are Wireless User Hardware mechanical, they will be inherently sensitive to temperature changes. This suggests a potential conflict between present ambitions to integrate the RF PA on to an RFIC and to integrate MEMS devices to reduce front-end component count and deliver a spectrally flexible phone. The combination of RF