Hi Allison,
That is a handy summation of the gains needed. If switching the pre-driver to a mosfet (or better bipolar transistors, if they provide the same gain advantage) could provide enough additional gain to relax the gain needed in the previous stages, then there would be room to tailor the gain (lower it at the lower frequencies). Before the design change of passing the TX signal through an additional 45Mhz filter that may have been possible. With the additional filter and the newly discovered IMD issues, more gain headroom may be needed than the gain than can be had by improving the pre-driver.?
Tom, wb6b
