Method and apparatus for controlling gain of an amplifier by comparing a detected output envelope and a reference signal

Claim 2

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is raised from a value lower than a rest value of said detector to a value higher than said rest value of said detector at a leading edge of the transmission output and is maintained at the value higher than the rest value of said detector and subsequently said level of the reference signal is smoothly raised.

Claim 3

The circuit according to claim 1, wherein a waveform of said reference signal which is smoothly raised is a cosine square waveform.

Claim 4

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is smoothly reduced to a value near a rest value of said detector at a trailing edge of the transmission output and is maintained at the value near the rest value of said detector and subsequently said level of the reference signal is reduced to the rest value of said detector or less.

Claim 5

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is smoothly reduced to a value near a rest value of said detector at a trailing edge of the transmission output and is maintained at the value near the rest value of said detector and subsequently said level of the reference signal is reduced to the rest value of said detector or less.

Claim 6

The circuit according to claim 3, wherein a waveform of said reference signal which is smoothly reduced is a cosine square waveform.

Claim 7

A power amplifying method comprising the step of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and raising a level of the reference signal from said reference signal generator from a value lower than a rest value of said detector to a value higher than the rest value of said detector at a leading edge of a transmission output from said variable gain power amplifier, maintaining said level at the value higher than the rest value of said detector and subsequently smoothly raising said level of the reference signal.

Claim 8

A power amplifying method comprising the step of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and raising a level of the reference signal from said reference signal generator from a value lower than a rest value of said detector to a value higher than the rest value of said detector at a leading edge of a transmission output from said variable gain power amplifier, maintaining said level at the value higher than the rest value of said detector and subsequently smoothly raising said level of the reference signal.

Claim 9

The method according claim 5, wherein a waveform of said reference signal which is smoothly raised is a cosine square waveform.

Claim 10

A power amplifying method comprising the steps of: detecting and envelope level of a output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and smoothly reducing a level of the reference signal from said reference signal generator to a value near a rest value of said detector at a trailing edge of a transmission output from said variable gain power amplifier, maintaining said level at the value near the rest value of said detector and subsequently reducing said level of the reference signal to rest value of said detector or less.

Claim 11

A power amplifying method comprising the steps of: detecting and envelope level of a output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and smoothly reducing a level of the reference signal from said reference signal generator to a value near a rest value of said detector at a trailing edge of a transmission output from said variable gain power amplifier, maintaining said level at the value near the rest value of said detector and subsequently reducing said level of the reference signal to rest value of said detector or less.

Claim 12

The method according to claim 7, wherein a waveform of said reference signal which is smoothly reduced is a cosine square waveform.

Claim 13

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator including an address generator receiving a transmission control signal for addressing a read only memory and a digital to analog convertor for converting an output of said read only memory for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is raised from a value lower than a rest value of said detector to a value higher than said rest value of said detector at a leading edge of the transmission output and is maintained at the value higher than the rest value of said detector, for a period of time during which said negative feedback loop operates and subsequently said level of the reference signal is smoothly raised.

Claim 14

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator including an address generator receiving a transmission control signal for addressing a read only memory and a digital to analog convertor for converting an output of said read only memory for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is raised from a value lower than a rest value of said detector to a value higher than said rest value of said detector at a leading edge of the transmission output and is maintained at the value higher than the rest value of said detector, for a period of time during which said negative feedback loop operates and subsequently said level of the reference signal is smoothly raised.

Claim 15

The circuit according to claim 9, wherein a waveform of said reference signal which is smoothly raised is a cosine square waveform.

Claim 16

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is smoothly reduced to a value near a rest value of said detector at a trailing edge of the transmission output and is maintained at the value near the rest value of said detector for a period of time during which said negative feedback loop operates and subsequently said level of the reference signal is reduced to the rest value of said detector or less.

Claim 17

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is smoothly reduced to a value near a rest value of said detector at a trailing edge of the transmission output and is maintained at the value near the rest value of said detector for a period of time during which said negative feedback loop operates and subsequently said level of the reference signal is reduced to the rest value of said detector or less.

Claim 18

The circuit according to claim 11, wherein a waveform of said reference signal which is smoothly reduced is a cosine square waveform.

Claim 19

A power amplifying method comprising the steps of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and raising a level of the reference signal from said reference signal generator from a value lower than a rest value of said detector to a value higher than the rest value of said detector at a leading edge of a transmission output from said variable gain power amplifier, maintaining said level at the value higher than the rest value of said detector for a period of time during which a negative feedback loop operates and subsequently raising said level of the reference signal smoothly.

Claim 20

A power amplifying method comprising the steps of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and raising a level of the reference signal from said reference signal generator from a value lower than a rest value of said detector to a value higher than the rest value of said detector at a leading edge of a transmission output from said variable gain power amplifier, maintaining said level at the value higher than the rest value of said detector for a period of time during which a negative feedback loop operates and subsequently raising said level of the reference signal smoothly.

Claim 21

The method according to claim 13, wherein a waveform of said reference signal which is smoothly raised is a cosine square waveform.

Claim 22

A power amplifying method comprising the steps of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and smoothly reducing a level of the reference signal from said reference signal generator to a value near a rest value of said detector at a trailing edge of a transmission output from said variable gain power amplifier, maintaining said level at the value near the rest value of said detector for a period of time during which a negative feedback loop operates and subsequently reducing said level of the reference signal to the rest value of said detector or less.

Claim 23

A power amplifying method comprising the steps of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and smoothly reducing a level of the reference signal from said reference signal generator to a value near a rest value of said detector at a trailing edge of a transmission output from said variable gain power amplifier, maintaining said level at the value near the rest value of said detector for a period of time during which a negative feedback loop operates and subsequently reducing said level of the reference signal to the rest value of said detector or less.

Claim 24

The method according to claim 15, wherein a waveform of said reference signal which is smoothly reduced is a cosine square waveform.

Claim 25

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is raised from a value lower than a rest value of said detector to a value higher than said rest value of said detector at a leading edge of the transmission output and is maintained at the value higher than the rest value of said detector and subsequently said level of the reference signal is smoothly raised from the start of the operation of said negative feedback loop.

Claim 26

A power amplifying circuit comprising: a variable gain power amplifier receiving a transmission signal and producing a transmission output; a detector for detecting an envelope level of an output of said variable gain power amplifier; a reference signal generator for generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform; and a negative feedback loop including means for comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby producing a control signal for controlling a gain of said variable gain power amplifier in accordance with a comparison output, wherein a level of the reference signal from said reference signal generator is raised from a value lower than a rest value of said detector to a value higher than said rest value of said detector at a leading edge of the transmission output and is maintained at the value higher than the rest value of said detector and subsequently said level of the reference signal is smoothly raised from the start of the operation of said negative feedback loop.

Claim 27

The circuit according to claim 17, wherein a waveform of said reference signal which is smoothly raised is a cosine square waveform.

Claim 28

A power amplifying method comprising the steps of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and raising a level of the reference signal from said reference signal generator from a value lower than a rest value of said detector to a value higher than the rest value of said detector at a leading edge of a transmission output from said variable gain power amplifier, maintaining said level at the value higher than the rest value of said detector and subsequently smoothly raising said level of the reference signal from the start of the operation of a negative feedback loop.

Claim 29

A power amplifying method comprising the steps of: detecting an envelope level of an output of a variable gain power amplifier using a detector; generating a reference signal to convert the envelope level of the output of said variable gain power amplifier to a smooth waveform using a reference signal generator; comparing the envelope level of the output of said variable gain power amplifier detected by said detector with a waveform of the reference signal from said reference signal generator, thereby controlling a gain of said variable gain power amplifier in accordance with a comparison output; and raising a level of the reference signal from said reference signal generator from a value lower than a rest value of said detector to a value higher than the rest value of said detector at a leading edge of a transmission output from said variable gain power amplifier, maintaining said level at the value higher than the rest value of said detector and subsequently smoothly raising said level of the reference signal from the start of the operation of a negative feedback loop.

Claim 30

The method according to claim 19, wherein a waveform of said reference signal which is smoothly raised is a cosine square waveform.