Linear compensating circuit

A linear compensating circuit for maintaining a linearity of an input-output characteristic of an amplifying means comprising:

• first level detection means for detecting a level of an input signal to be inputted to said amplifying means;
• second level detection means for detecting a level of an output signal to be outputted from said amplifying means;
• amplitude compensating means for controlling an amplitude of said input signal in accordance with a difference between a signal level detected by said first detection means and a signal level detected by said second detection means to improve said linearity of said input-output characteristic of said amplifying means;
• and
• phase compensating means for controlling a phase of said input signal in accordance with a level of an output signal detected by said second level detection means;
• and
• wherein said phase compensating means has a characteristic that cancels a phase change of said output signal induced by amplitude compensation of said amplitude compensating means.

A linear compensating circuit for maintaining a linearity of an input-output characteristic of an amplifying means comprising:

• first level detection means for detecting a level of an input signal to be inputted to said amplifying means;
• second level detection means for detecting a level of an output signal to be outputted from said amplifying means;
• amplitude compensating means for controlling an amplitude of said input signal in accordance with a difference between a signal level detected by said first detection means and a signal level detected by said second detection means to improve said linearity of said input-output characteristic of said amplifying means;
• and
• phase compensating means for controlling a phase of said input signal in accordance with a level of an output signal detected by said second level detection means;
• wherein at least one of said input and output signals is provided through a branching circuit;
• and wherein said branching circuit has means for controlling the level of a signal to be provided.

An amplifier comprising:

• amplifier means;
• first level detection means for detecting a level of an input signal to be inputted to said amplifying means;
• second level detection means for detecting a level of an output signal to be inputted to said amplifying means;
• amplitude compensating means for controlling an amplitude of said input signal in accordance with a difference between a signal level detected by said first detection means and a signal level detected by said second detection means to improve a linearity of an input-output characteristic of said amplifying means;
• and
• phase compensating means for controlling a phase of said input signal in accordance with a level of an output signal detected by said second level detection means;
• and
• wherein said phase compensating means has a characteristic that cancels a phase change of said output signal induced by amplitude compensation of said amplitude compensating means.

An amplifier comprising:

• amplifier means;
• first level detection means for detecting a level of an input signal to be inputted to said amplifying means;
• second level detection means for detecting a level of an output signal to be inputted to said amplifying means;
• amplitude compensating means for controlling an amplitude of said input signal in accordance with a difference between a signal level detected by said first detection means and a signal level detected by said second detection means to improve a linearity of an input-output characteristic of said amplifying means;
• and
• phase compensating means for controlling a phase of said input signal in accordance with a level of an output signal detected by said second level detection means;
• and
• wherein at least one of said input and output signals is provided through a branching circuit and wherein said branching circuit includes means for controlling the level of a signal to be provided.

A linear compensating circuit for compensating a linearity of an input-output characteristic of amplifying means comprising:

• first level detection means for detecting a level of an input signal to be inputted to said amplifying means;
• second level detection means for detecting a level of an input signal to be inputted to said amplifying means;
• amplitude compensating means for controlling an amplitude of said input signal in accordance with a difference between a signal level detected by said first detection means and a signal level detected by said second detection means thereby improving a linearity of an input-output characteristic of said amplifying means;
• phase compensating means for controlling a phase of said input signal in accordance with a level of an output signal detected by said second level detection means;
• and
• a differential amplifier for amplifying a difference between an output of said first level detection means and an output of said second detection means to send it to said amplitude compensating means.

An amplifier comprising:

• amplifier means;
• first level detection means for detecting a level of an input signal to be inputted to said amplifying means;
• second level detection means for detecting a level of an output signal to be inputted to said amplifying means;
• amplitude compensating means for controlling an amplitude of said input signal in accordance with a difference between a signal level detected by said first detection means and a signal level detected by said second detection means to improve a linearity of an input-output characteristic of said amplifying means;
• phase compensating means for controlling a phase of said input signal in accordance with a level of an output signal detected by said second level detection means;
• and a differential amplifier for amplifying a difference between an output of said first level detection means and an output of said second detection means to send it to said amplitude compensating means.