Linearization of broadband power amplifiers

A linearizer for a power amplifier receiving a baseband input signal, comprising:

• a baseband analog predistorter for predistorting the baseband input signal comprising one or more polynomial circuits, the polynomial circuits each comprising analog multipliers, summers and one or more complex multipliers and each implementing a polynomial function in the form of
• f
• ⁡
• (
• x
• )
• =
• ∑
• k
• =
• 1
• n
• ⁢
• a
• k
• ⁢
• x
• k
• ,
• where n is an integer greater than one;
• and
• an up-converter for up-converting the predistorted baseband input signal to a frequency designated for transmission by the power amplifier.

A method for linearizing a power amplifier, comprising:

• up-converting a baseband input signal that is to be transmitted by the power amplifier;
• predistorting the up-converted input signal in an RF analog predistorter controlled by a set of coefficients;
• down-converting an output signal of the power amplifier;
• obtaining an error signal that is a difference between the down-converted output signal and the input signal;
• and
• monitoring the error signal in a signal analyzer, the signal analyzer using an out-of-band power spectrum of the error signal to optimize the set of coefficients.

A method for linearizing a power amplifier, comprising:

• receiving a baseband input signal;
• predistorting the baseband input signal in a baseband analog predistorter that comprises one or more polynomial circuits, the polynomial circuits each comprising analog multipliers, summers and one or more complex multipliers and each implementing a polynomial function in the form of
• f
• ⁡
• (
• x
• )
• =
• ∑
• k
• =
• 1
• n
• ⁢
• a
• k
• ⁢
• x
• k
• ,
• where n is an integer greater than one;
• and
• up-converting the predistorted baseband input signal to a frequency designated for transmission by the power amplifier.