Methods and apparatus for reducing modulation signal bandwidth in polar modulation transmitters

A polar modulation transmitter comprising:

• a phase path configured to receive a phase difference modulation signal;
• and
• a phase difference reduction circuit comprises a linear-phase filter configured to generate a phase-difference-adjusted phase difference modulation signal from said phase difference modulation signal, and a peak detector operable to detect occurrences in said phase difference modulation signal having phase difference values that exceed a phase difference threshold, wherein filtering is performed on the phase difference modulation signals that exceed the phase difference threshold.

An apparatus for reducing the bandwidth of modulation signals in a phase path of a polar modulation transmitter, comprising:

• means for generating a phase difference modulation signal;
• and
• means for filtering said phase difference modulation signal to produce a phase-difference-adjusted phase difference modulation signal that is linearly related to said phase difference modulation signal, wherein said means for filtering said phase difference modulation signal includes means for detecting occurrences in said phase difference modulation signal having phase difference values that exceed a phase difference threshold and filtering is performed on the phase difference modulation signals that exceed the phase difference threshold.