A system and method to optimize the efficiency of an amplifier device is provided by the including a non-linear amplifier in a mobile radio device. This may further include a front cable guard movably attached to the tray framework proximate the front end such that the guard is movable vertically downward from a guarding position to a downward position when the tray framework is in an outward position, and further wherein the guard is slidable rearward from the downward position to a downward retracted position. Furthermore, high power conversion efficiency can also be attained in a low-temperature thermal annealing process. Therefore, uniformity of the plasma process on the surface of the substrate is improved. Grouping can be carried out based on the telephone numbers of senders and the like during rearrangement of facsimile data. The polishing surface may have one or more pockets formed therein.