Efficient linear power amplification

Claim 1

A method for producing amplified signals for communications having reduced adjacent channel energy, said method comprising the steps of: generating a first signal having an undesired amount of adjacent channel energy; generating a second signal corresponding to the undesired amount of adjacent channel energy; and subtracting said second signal from said first signal to remove said undesired amount of adjacent channel energy.

Claim 2

A method for producing amplified signals for communications having reduced adjacent channel energy, said method comprising the steps of: generating a first signal having an undesired amount of adjacent channel energy; generating a second signal corresponding to the undesired amount of adjacent channel energy; and subtracting said second signal from said first signal to remove said undesired amount of adjacent channel energy.

Claim 10

A method for amplifying communications signals exhibiting reduced adjacent channel energy, said method comprising the steps of: generating I, Q modulation signals wherein a sum of the squares of instantaneous I and Q signals is a constant; applying said I, Q signals to a quadrature modulator operating on sine and cosine carrier frequency signals to obtain a constant-envelope signal; amplifying said constant envelope signal using a power amplifier designed to yield high efficiency with constant-envelope signals; high-pass filtering said I and Q signals and applying said high-pass filtered signals to a second quadrature modulator to obtain an error signal; amplifying said error signal using a linear amplifier adapted to effectively amplify varying amplitude signals; and adding an output of said power amplifier to an output of said linear amplifier in order to obtain a signal having reduced adjacent channel energy.

Claim 11

A method for amplifying communications signals exhibiting reduced adjacent channel energy, said method comprising the steps of: generating I, Q modulation signals wherein a sum of the squares of instantaneous I and Q signals is a constant; applying said I, Q signals to a quadrature modulator operating on sine and cosine carrier frequency signals to obtain a constant-envelope signal; amplifying said constant envelope signal using a power amplifier designed to yield high efficiency with constant-envelope signals; high-pass filtering said I and Q signals and applying said high-pass filtered signals to a second quadrature modulator to obtain an error signal; amplifying said error signal using a linear amplifier adapted to effectively amplify varying amplitude signals; and adding an output of said power amplifier to an output of said linear amplifier in order to obtain a signal having reduced adjacent channel energy.

Claim 13

A method of generating amplified, digital data-modulated signals exhibiting reduced adjacent channel energy, said method comprising the steps of: generating I, Q modulated signals representing digital data, said signals having greater than desired adjacent channel energy; applying said I, Q signals to a quadrature modulator operating on sine and cosine carrier frequency signals to obtain a first signal; high-pass filtering said I, Q modulation signals to obtain high-pass filtered I, Q signals; applying said high-pass filtered I, Q signals to a second quadrature modulator to obtain a second signal; and amplifying and adding said first and second signals to obtain a signal having reduced adjacent channel energy.

Claim 14

A method of generating amplified, digital data-modulated signals exhibiting reduced adjacent channel energy, said method comprising the steps of: generating I, Q modulated signals representing digital data, said signals having greater than desired adjacent channel energy; applying said I, Q signals to a quadrature modulator operating on sine and cosine carrier frequency signals to obtain a first signal; high-pass filtering said I, Q modulation signals to obtain high-pass filtered I, Q signals; applying said high-pass filtered I, Q signals to a second quadrature modulator to obtain a second signal; and amplifying and adding said first and second signals to obtain a signal having reduced adjacent channel energy.

Claim 15

A method for generating amplified, digital data modulated to obtain signals reduced adjacent channel energy, said method comprising the steps of: generating I, Q signals corresponding to a constant-envelope digital data modulation; applying said I, Q signals to a quadrature modulator operating on sine and cosine carrier frequency signals to obtain a constant-envelope signal; amplifying said constant envelope signal using a power amplifier designed to yield high efficiency with constant-envelope signals; high-pass filtering said I, Q signals and applying the resulting high-pass filtered signals to a second quadrature modulator to obtain an error signal; amplifying said error signal using a linear amplifier adapted to varying amplitude signals; and adding output of said power amplifier to output of said linear amplifier to obtain a signal having reduced adjacent channel energy.

Claim 16

A method for generating amplified, digital data modulated to obtain signals reduced adjacent channel energy, said method comprising the steps of: generating I, Q signals corresponding to a constant-envelope digital data modulation; applying said I, Q signals to a quadrature modulator operating on sine and cosine carrier frequency signals to obtain a constant-envelope signal; amplifying said constant envelope signal using a power amplifier designed to yield high efficiency with constant-envelope signals; high-pass filtering said I, Q signals and applying the resulting high-pass filtered signals to a second quadrature modulator to obtain an error signal; amplifying said error signal using a linear amplifier adapted to varying amplitude signals; and adding output of said power amplifier to output of said linear amplifier to obtain a signal having reduced adjacent channel energy.

Claim 18

A method of generating amplified, digital data modulated signals to provide reduced adjacent channel energy, said method comprising the steps of: feeding digital data signals through a shift register of N stages; coupling N signals from said shift register corresponding to the last N data bits of said digital data signals to address input lines of a read only memory; connecting address lines of said read only memory to the digit lines of a counter; incrementing said counter to obtain sequentially a number of sets of four output values from said read only memory; digital-to-analog converting said four output values to obtain a first I, Q signal and a second I, Q signal; applying said first I, Q signal to a first quadrature modulator to obtain a first signal of higher than desired adjacent channel energy; applying said second I, Q signal to a second quadrature modulator to obtain a second signal; and adding said first signal to said second signal in an optimum ratio to obtain a signal of reduced adjacent channel energy.

Claim 19

A method of generating amplified, digital data modulated signals to provide reduced adjacent channel energy, said method comprising the steps of: feeding digital data signals through a shift register of N stages; coupling N signals from said shift register corresponding to the last N data bits of said digital data signals to address input lines of a read only memory; connecting address lines of said read only memory to the digit lines of a counter; incrementing said counter to obtain sequentially a number of sets of four output values from said read only memory; digital-to-analog converting said four output values to obtain a first I, Q signal and a second I, Q signal; applying said first I, Q signal to a first quadrature modulator to obtain a first signal of higher than desired adjacent channel energy; applying said second I, Q signal to a second quadrature modulator to obtain a second signal; and adding said first signal to said second signal in an optimum ratio to obtain a signal of reduced adjacent channel energy.

Claim 20

An apparatus for producing amplified signals for communications having reduced adjacent channel energy, said apparatus comprising: means for generating a first signal having an undesired amount of adjacent channel energy; means for generating a second signal corresponding to the undesired amount of adjacent channel energy; and means for subtracting said second signal from said first signal to remove said undesired amount of adjacent channel energy.

Claim 21

An apparatus for producing amplified signals for communications having reduced adjacent channel energy, said apparatus comprising: means for generating a first signal having an undesired amount of adjacent channel energy; means for generating a second signal corresponding to the undesired amount of adjacent channel energy; and means for subtracting said second signal from said first signal to remove said undesired amount of adjacent channel energy.

Claim 29

An apparatus for producing amplified communications signals with reduced adjacent channel energy, said apparatus comprising: means for generating I, Q modulation signals wherein a sum of the squares of instantaneous I and Q signals is a constant; a first quadrature modulator for applying sine and cosine carrier frequency signals to said I, Q signals to obtain a constant-envelope signal; a power amplifier designed to yield high efficiency with constant-envelope signals for amplifying said constant envelope signal; a high-pass filter for high-pass filtering said I and Q signals; a second quadrature modulator for applying sine and cosine carrier frequency signals to said high-pass filtered signals to obtain an error signal; a linear amplifier adapted to effectively amplify varying amplitude signals for amplifying said error signal; and an adder for adding an output of said power amplifier to an output of said linear amplifier in order to obtain a signal having reduced adjacent channel energy.

Claim 30

An apparatus for producing amplified communications signals with reduced adjacent channel energy, said apparatus comprising: means for generating I, Q modulation signals wherein a sum of the squares of instantaneous I and Q signals is a constant; a first quadrature modulator for applying sine and cosine carrier frequency signals to said I, Q signals to obtain a constant-envelope signal; a power amplifier designed to yield high efficiency with constant-envelope signals for amplifying said constant envelope signal; a high-pass filter for high-pass filtering said I and Q signals; a second quadrature modulator for applying sine and cosine carrier frequency signals to said high-pass filtered signals to obtain an error signal; a linear amplifier adapted to effectively amplify varying amplitude signals for amplifying said error signal; and an adder for adding an output of said power amplifier to an output of said linear amplifier in order to obtain a signal having reduced adjacent channel energy.

Claim 33

An apparatus for generating amplified, digital data modulated signals exhibiting with adjacent channel energy, said apparatus comprising: means for generating I, Q signals representing digital data modulation, said signals having greater than desired adjacent channel energy; a first quadrature modulator to which said I, Q signals are applied and operating on sine and cosine carrier frequency signals to obtain a first signal; means for high-pass filtering said I, Q modulation signals to obtain high-pass filtered I, Q signals; a second quadrature modulator to which said high-pass filtered I, Q signals are applied to obtain a second signal; and an adder for adding said first and second signals to obtain a signal having reduced adjacent channel energy.

Claim 34

An apparatus for generating amplified, digital data modulated signals exhibiting with adjacent channel energy, said apparatus comprising: means for generating I, Q signals representing digital data modulation, said signals having greater than desired adjacent channel energy; a first quadrature modulator to which said I, Q signals are applied and operating on sine and cosine carrier frequency signals to obtain a first signal; means for high-pass filtering said I, Q modulation signals to obtain high-pass filtered I, Q signals; a second quadrature modulator to which said high-pass filtered I, Q signals are applied to obtain a second signal; and an adder for adding said first and second signals to obtain a signal having reduced adjacent channel energy.

Claim 35

An apparatus for generating amplified, digital data modulated signals with reduced adjacent channel energy, said apparatus comprising: means for generating I, Q signals corresponding to a constant-envelope digital data modulation; a first quadrature modulator to which said I, Q signals are applied and operating on sine and cosine carrier frequency signals to obtain a constant-envelope signal; a power amplifier designed to yield high efficiency with constant-envelope signals for amplifying said constant envelope signal; means for high-pass filtering said I, Q signals; a second quadrature modulator to which said high-pass filtered signals to obtain an error signal; a linear amplifier adapted to varying amplitude signals for amplifying said error signal; and an adder for adding output of said power amplifier to output of said linear amplifier to obtain a signal having reduced adjacent channel energy.

Claim 36

An apparatus for generating amplified, digital data modulated signals with reduced adjacent channel energy, said apparatus comprising: means for generating I, Q signals corresponding to a constant-envelope digital data modulation; a first quadrature modulator to which said I, Q signals are applied and operating on sine and cosine carrier frequency signals to obtain a constant-envelope signal; a power amplifier designed to yield high efficiency with constant-envelope signals for amplifying said constant envelope signal; means for high-pass filtering said I, Q signals; a second quadrature modulator to which said high-pass filtered signals to obtain an error signal; a linear amplifier adapted to varying amplitude signals for amplifying said error signal; and an adder for adding output of said power amplifier to output of said linear amplifier to obtain a signal having reduced adjacent channel energy.

Claim 38

An apparatus for generating amplified, digital data modulated signals with reduced adjacent channel energy, said apparatus comprising: a shift register of N stages to which digital data input signals are input; a read only memory having address input lines to which are coupled to N signals from said shift register corresponding to the last N data bits of said digital data signals; a counter having digit lines to which are connected to address lines of said read only memory; means for incrementing said counter to obtain sequentially a number of sets of four output values from said read only memory; digital-to-analog convertor for converting said four output values to obtain a first I, Q signal and a second I, Q signal; a first quadrature modulator to which said first I, Q signal is applied to obtain a first signal of higher than desired adjacent channel energy; a second quadrature modulator to which said second I, Q signal is applied to obtain a second signal; and an adder for adding said first signal to said second signal in an optimum ratio to obtain a signal of reduced adjacent channel energy.

Claim 39

An apparatus for generating amplified, digital data modulated signals with reduced adjacent channel energy, said apparatus comprising: a shift register of N stages to which digital data input signals are input; a read only memory having address input lines to which are coupled to N signals from said shift register corresponding to the last N data bits of said digital data signals; a counter having digit lines to which are connected to address lines of said read only memory; means for incrementing said counter to obtain sequentially a number of sets of four output values from said read only memory; digital-to-analog convertor for converting said four output values to obtain a first I, Q signal and a second I, Q signal; a first quadrature modulator to which said first I, Q signal is applied to obtain a first signal of higher than desired adjacent channel energy; a second quadrature modulator to which said second I, Q signal is applied to obtain a second signal; and an adder for adding said first signal to said second signal in an optimum ratio to obtain a signal of reduced adjacent channel energy.