Power- conserving drive-modulation method for envelope-elimination-and-restoration (EER) transmitters

Claim 2

A transmitter, comprising: a) a first amplifier, said first amplifier having a signal input, a first supply-voltage input, and a first amplifier output; b) a driver having a second supply-voltage input and a driver output; and c) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a third supply-voltage input, and said first amplifier being coupled to said third supply-voltage input of said final amplifier for modulating said final amplifier, said transmitter being characterized in that: said first amplifier is also coupled to said second supply-voltage input of said driver for modulating said driver, whereby said first amplifier performs as a first modulator and said transmitter being further characterized in that said drive level of said final amplifier is controlled by a DC offset voltage applied to said driver for setting said minimum drive level for ensuring linear modulation of said final amplifier.

Claim 3

A transmitter as recited in claim 1 , wherein said transmitter is of the envelope-elimination-and-restoration type.

Claim 4

A transmitter as recited in claim 1 , wherein said transmitter is of the envelope-tracking type.

Claim 5

A transmitter as recited in claim 1 , further comprising a first filter for filtering said first amplifier output.

Claim 6

A transmitter as recited in claim 1 , further comprising a second filter for filtering said final amplifier output.

Claim 7

A transmitter as in claim 1 , wherein said first amplifier comprises an amplifier selected from the group consisting of Class S, Class G, pulse step, and split band amplifiers, and combinations thereof.

Claim 8

A transmitter as in claim 1 , wherein said final amplifier comprises an amplifier selected from the group consisting of Class A, Class B, Class C, Class D, Class E, and Class F amplifiers, and combinations thereof.

Claim 9

A transmitter comprising: a) a first modulator, said first modulator having a first signal input, a first supply-voltage input, and a first modulator output; b) a second modulator separate from said first modulator, said second modulator having a second signal input, a second supply-voltage input, and a second modulator output; c) a driver having a third supply-voltage input and a driver output, said second modulator output being coupled to said third supply-voltage input of said driver for modulating said driver; and d) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a fourth supply-voltage input, said first modulator output being coupled to said fourth supply-voltage input of said final amplifier for modulating said final amplifier.

Claim 10

A transmitter comprising: a) a first modulator, said first modulator having a first signal input, a first supply-voltage input, and a first modulator output; b) a second modulator separate from said first modulator, said second modulator having a second signal input, a second supply-voltage input, and a second modulator output; c) a driver having a third supply-voltage input and a driver output, said second modulator output being coupled to said third supply-voltage input of said driver for modulating said driver; and d) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a fourth supply-voltage input, said first modulator output being coupled to said fourth supply-voltage input of said final amplifier for modulating said final amplifier.

Claim 11

A transmitter as recited in claim 8 , wherein said transmitter is of the envelope-elimination-and-restoration type.

Claim 12

A transmitter as recited in claim 8 , wherein said transmitter is of the envelope-tracking type.

Claim 13

A transmitter as recited in claim 8 , said final amplifier having a drive level, wherein said drive level of said final amplifier is controlled to maintain a minimum drive level for ensuring linear modulation of said final amplifier.

Claim 14

A transmitter as recited in claim 8 , further comprising a first filter for filtering said first modulator output.

Claim 15

A transmitter as recited in claim 8 , further comprising a second filter for filtering said final amplifier output.

Claim 16

A transmitter as recited in claim 8 , further comprising a third filter for filtering said second modulator output.

Claim 17

A transmitter as in claim 8 wherein said first modulator comprises an amplifier selected from the group consisting of Class S, Class G, pulse step, and split band amplifiers, and combinations thereof.

Claim 18

A transmitter as in claim 8 wherein said second modulator comprises an amplifier selected from the group consisting of Class S, Class G, pulse step, and split band amplifiers, and combinations thereof.

Claim 19

A transmitter as in claim 8 , further comprising an envelope detector whose envelope output is coupled to said signal input of said first modulator.

Claim 20

A transmitter as in claim 17 further comprising a summing circuit coupled between said envelope detector and said driver.

Claim 21

A transmitter as in claim 18 , wherein said summing circuit comprises: i) a variable gain control device; ii) a summing device, said variable gain control device being coupled between said envelope detector and said summing device; and iii) a variable DC bias control device coupled to said summing device for controlling said drive level of said final amplifier to maintain a minimum drive level for ensuring linear modulation of said final amplifier.

Claim 22

A transmitter having a signal input, said transmitter comprising: a) an envelope detector for forming an envelope signal; b) a delay module, said signal input being coupled to both said envelope detector and said delay module; c) a limiter coupled to said delay module; d) a first modulator, said first modulator having a first supply-voltage input and a first modulator output; e) a second modulator separate from said first modulator, said second modulator having a second supply-voltage input and a second modulator output, said envelope detector being coupled to both said first and second modulators; f) a local oscillator and a mixer coupled to said limiter for providing a delayed phase-modulated signal; g) a driver accepting said delayed phase-modulated signal, said driver having a third supply-voltage input and a driver output, said second modulator output being coupled to said third supply-voltage input of said driver for modulating said driver; and h) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a fourth supply-voltage input, said first modulator output being coupled to said fourth supply-voltage input of said final amplifier for modulating said final amplifier.

Claim 23

A transmitter having a signal input, said transmitter comprising: a) an envelope detector for forming an envelope signal; b) a delay module, said signal input being coupled to both said envelope detector and said delay module; c) a limiter coupled to said delay module; d) a first modulator, said first modulator having a first supply-voltage input and a first modulator output; e) a second modulator separate from said first modulator, said second modulator having a second supply-voltage input and a second modulator output, said envelope detector being coupled to both said first and second modulators; f) a local oscillator and a mixer coupled to said limiter for providing a delayed phase-modulated signal; g) a driver accepting said delayed phase-modulated signal, said driver having a third supply-voltage input and a driver output, said second modulator output being coupled to said third supply-voltage input of said driver for modulating said driver; and h) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a fourth supply-voltage input, said first modulator output being coupled to said fourth supply-voltage input of said final amplifier for modulating said final amplifier.

Claim 24

A transmitter as recited in claim 20 , wherein said signal input of said transmitter is provided by a modulator producing an analog RF signal at the desired frequency of said RF output of said final amplifier or at a suitable intermediate frequency.

Claim 25

A transmitter as recited in claim 20 , wherein said drive level of said final amplifier is controlled to maintain a minimum drive level for ensuring linear modulation of said final amplifier.

Claim 26

A transmitter as in claim 20 further comprising a summing circuit coupled between said envelope detector and said driver.

Claim 27

A transmitter as in claim 23 , wherein said summing circuit comprises: i) a variable gain control device; ii) a summing device, said variable gain control device being coupled between said envelope detector and said summing device; and iii) a variable DC bias control device coupled to said summing device for controlling said drive level of said final amplifier to maintain a minimum drive level for ensuring linear modulation of said final amplifier.

Claim 28

A transmitter having an RF signal input, said transmitter comprising: a) a modulator, said modulator having an envelope signal input, a first supply-voltage input, and a modulator output; b) a driver having a driver input, a second supply-voltage input, and a driver output; c) an envelope detector operating on said signal input of said transmitter and whose envelope output is coupled to said envelope signal input of said modulator; d) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a third supply-voltage input, said modulator output being coupled to said third supply-voltage input of said final amplifier for modulating said final amplifier; and e) a first variable gain control device operating on said RF signal input and coupled to said driver input.

Claim 29

A transmitter having an RF signal input, said transmitter comprising: a) a modulator, said modulator having an envelope signal input, a first supply-voltage input, and a modulator output; b) a driver having a driver input, a second supply-voltage input, and a driver output; c) an envelope detector operating on said signal input of said transmitter and whose envelope output is coupled to said envelope signal input of said modulator; d) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a third supply-voltage input, said modulator output being coupled to said third supply-voltage input of said final amplifier for modulating said final amplifier; and e) a first variable gain control device operating on said RF signal input and coupled to said driver input.

Claim 30

A transmitter as recited in claim 25 , further comprising: f) a delay module operating on said signal input of said transmitter; g) a limiter coupled to said delay module; and h) a local oscillator and a mixer coupled to said limiter for providing a delayed phase-modulated signal.

Claim 31

A transmitter as recited in claim 25 , further comprising a summing circuit coupled between said envelope detector and said first variable gain control device.

Claim 32

A transmitter as recited in claim 27 , wherein said summing circuit comprises: i) a second variable gain control device; ii) a summing device, said second variable gain control device being coupled between said envelope detector and said summing device; and iii) a variable DC bias control device coupled to said summing device for controlling said drive level of said final amplifier to maintain a minimum drive level for ensuring linear modulation of said final amplifier.

Claim 33

A transmitter as recited in claim 25 , wherein said RF signal input of said transmitter is provided by a modulator producing an analog RF signal at the desired frequency of said RF output of said final amplifier or at a suitable intermediate frequency.

Claim 34

A transmitter having a baseband or other input, comprising: a) a first modulator, said first modulator having a first signal input, a first supply-voltage input, and a first modulator output; b) a second modulator separate from said first modulator, said second modulator having a second signal input, a second supply-voltage input, and a second modulator output; c) a driver having a third supply-voltage input and a driver output, said second modulator output being coupled to said third supply-voltage input of said driver for modulating said driver; d) a digital signal processor and digital-to-analog converter circuit, said digital signal processor operating on said baseband or other input of the transmitter and said circuit having a first analog or digital envelope output coupled to said first modulator, and a second analog or digital output coupled to said second modulator, said second analog or digital output including both gain and DC-offset adjustments to said envelope; and e) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a fourth supply-voltage input, said first modulator output being coupled to said fourth supply-voltage input of said final amplifier for modulating said final amplifier.

Claim 35

A transmitter having a baseband or other input, comprising: a) a first modulator, said first modulator having a first signal input, a first supply-voltage input, and a first modulator output; b) a second modulator separate from said first modulator, said second modulator having a second signal input, a second supply-voltage input, and a second modulator output; c) a driver having a third supply-voltage input and a driver output, said second modulator output being coupled to said third supply-voltage input of said driver for modulating said driver; d) a digital signal processor and digital-to-analog converter circuit, said digital signal processor operating on said baseband or other input of the transmitter and said circuit having a first analog or digital envelope output coupled to said first modulator, and a second analog or digital output coupled to said second modulator, said second analog or digital output including both gain and DC-offset adjustments to said envelope; and e) a final amplifier having a final amplifier input coupled to said driver output, said final amplifier having a drive level, an RF output, and a fourth supply-voltage input, said first modulator output being coupled to said fourth supply-voltage input of said final amplifier for modulating said final amplifier.

Claim 36

A transmitter as in claim 30 , further comprising: a quadrature modulator circuit coupled between said digital signal processor and digital-to-analog converter circuit and said driver.

Claim 37

A transmitter as in claim 30 , further comprising: i) a quadrature modulator circuit; ii) a frequency source; and iii) a mixer, said quadrature modulator circuit being coupled between said digital signal processor and digital-to-analog converter circuit and said mixer; said frequency source being coupled to said mixer, and said mixer being coupled to said driver input.