Talk:Polar modulation

From Wikipedia, the free encyclopedia

[edit] Linearity issues

It is unclear whether a linear PA is vital to implement a polar modulator or not. The first part of the article says it's absolutely vital, whereas the second suggests that acutally a highly non-linear PA can be used. --Romanski 08:54, 19 July 2006 (UTC)

A linear PA can be used, it's sufficient but not necessary. The value in choosing a non-linear PA over a linear PA is that the non-linear PA provides better efficiency. Theoretically, the maximum efficiency of a perfectly linear Class A PA is 25%; so for every 4 watts consumed from the battery only 1 watt is available at the output. The rest is lost to heat. Whereas a highly non-linear (for example Class E) PA has been shown to have over 80% efficiency; for every 4 watts of battery consumption only 0.8 watts is lost to heat and 3.2 watts is available at the output. --Dtwitkowski 06:52, 20 July 2006 (UTC)

I see now, thanks for clarifying this. In fact I misread the article and thought that the second paragraph was referring to a polar modulator, whereas it clearly states at the start that it's talking about quadrature modulator. --Romanski 08:54, 20 July 2006 (UTC)