This reference voltage allows the selection of the nine different, required RF power levels. The APC loop transient behavior and compensation for output power variations across frequency bands and under environmental conditions should also be considered. Several sometimes-conflicting requirements must be considered in the selection of both the architecture and parts of the transmitter. Of course, PCB space and cost are always important considerations. This requirement will impact the new wireless data terminal's battery life, and attention must be paid to the packaging and related thermal issues.
Many factors determine the handset receiver and transmitter optimum frequency plan.
This strategy leads to simpler front-end filters with lower insertion loss, reduced cost, and smaller size. A higher first IF simplifies the 1 st and Half-IF image rejection problem, but a larger and more expensive IF SAW filter might be required. The frequency plan also affects the level of transmitter output spurious products and the associated filtering requirements. Also, lower-risk development cycles are achieved. Clearly, further integration requires solving the passive parts integration problem in a cost-effective manner that is compatible with today's extremely short development schedules.