TS/LTE 2.6 GHZ extension band) and Band 38 (LTE TDD in the Band VII duplex gap). A third module would cover the US and European DDR bands at 700 and 800 MHz. Option 3 would be as Option 2 but extended down to cover the 700- and 800-MHz DDR bands. Option 4 would be as option 3 but extended up to cover the 2.6-GHz band. Option 534 would be to have a PA module for bands below 1 GHz, a second module for bands up to and including Band I and a third module for frequencies above 2.1 GHz. However, this option would be significantly different from existing solutions available in the market. Option 6 would be one wideband power amplifier to cover all bands. 33 Source Peregrine July 2010. Based on conversations with Nujira 18 Feb 2009, though see earlier comments on LTE energy drain. Wireless User Hardware Option 6 would presently be ambitious both from a PA design perspective and would be dependent on implementing wideband phase-lock loop architectures with acceptable noise performance, availability of sufficiently efficient wideband adaptive matching and availability of sufficiently efficient wideband linearisation techniques. Note that PA bandwidth is limited not by the active device but by the bandwidth of the output matching circuit. An output matching circuit is necessary because of the inherent impedance difference between the antenna and the PA device. Five volts (or less) causes the RF output device to have an output impedance of well below 50 ohms. Devices following the PA for example directional couplers, filters, antennas and isolators have 50 ohm impedance and SO an impedance matching circuit (passive) is required. The realisation of this network will limit the bandwidth. Using a supply above five volts will enable the PA output transistor to be operated nearer to a 50-ohm output impedance thus relaxing but not entirely removing the requirements on the bandwidth-limiting impedance transformation network. By this means, PA bandwidths of an octave become possible. In order to linearise PA operation, some vendors 