Patent ID: 6230031
Filing Date: 2001-05-08
Classification: H01Q,H03F,H04B

Abstract:
A power amplifying circuit comprising:a first means for amplifying, coupled to a first voltage source, for amplifying a radio frequency (RF) signal from a hand held radio transmitter to produce an output RF signal; anda first means for maintaining the magnitude of said output RF signal at a selected one of a first set of levels,wherein said power amplifying circuit is couplable to a second means for amplifying, coupled to a second voltage source, for amplifying said output RF signal to form an amplified output RF signal, and a second means for maintaining said amplified output RF signal at a fixed gain level, said second voltage source providing a voltage having a magnitude greater than the magnitude of the voltage provided by said first voltage source, said power amplifying circuit further comprising:a means for detecting the presence of said second amplifying means;a means for adding, upon detection of said second amplifying means, two levels to the first set of levels, the two levels being lower in magnitude than a lowest level in the first set of levels, the first set of levels and the two levels lower in magnitude together defining a second set of levels;a means for selecting a predetermined one of the second set of levels when said second amplifying means is detected; anda means for applying said fixed gain level, said fixed gain level having a magnitude greater than the magnitude of any level of the first set of levels and the second set of levels, to said second maintaining means.