Shielding cover effects on the RF performance of LDMOSFET power amplifier for WCDMA application
Shielding cover effects on the RF performance of LDMOSFET power amplifier (PA) is investigated. In our measurement, the PA cover is made of aluminum, with its height adjusted from 8.4 to 14.4mm which are widely used in current wireless communication application. The input-output responses of several PA samples with cover are measured and compared for different cover heights. Both experiment and simulation show that as the cover height is reduced, the PA performance is degraded, but its power efficiency and linearity are not varied approximately. Further, it is found that, even the cover height is decreased, but through careful optimizing of its internal impedance matching networks consisting of multiple bonding wires, the PA performance can be improved effectively. This research can provide some useful design guidance for the development of compact and miniaturized PA module with high performance.