Median frequency generator

Claim 1

A device for generating an output signal having a frequency which is the median of the frequencies of a pair of original input signals comprising; adder means for receiving said original input signals and for generating a sum signal having a frequency equal to said median frequency and phase reversal points occurring at a frequency equal to one-half the difference between the frequencies of said input signals; zero level detector means connected to the output of said adder means for detecting all of the zero level locations of said sum signals; phase reversal discriminating means connected to the output of said zero level detector means for detecting the locations of those zero levels in which a phase reversal occurs and for generating timing signals in response thereto; and transmitting means including phase reversal means responsive to said timing signal for selectively inverting the phase of said sum signal to remove said phase reversal points and for transmitting said sum signal at said median frequency.

Claim 2

A device for generating an output signal having a frequency which is the median of the frequencies of a pair of original input signals comprising; adder means for receiving said original input signals and for generating a sum signal having a frequency equal to said median frequency and phase reversal points occurring at a frequency equal to one-half the difference between the frequencies of said input signals; zero level detector means connected to the output of said adder means for detecting all of the zero level locations of said sum signals; phase reversal discriminating means connected to the output of said zero level detector means for detecting the locations of those zero levels in which a phase reversal occurs and for generating timing signals in response thereto; and transmitting means including phase reversal means responsive to said timing signal for selectively inverting the phase of said sum signal to remove said phase reversal points and for transmitting said sum signal at said median frequency.

Claim 4

A device for generating an output signal having a frequency which is the median of the frequencies of a pair of original input signals comprising; first adder means for receiving said original input signals and for generating a sum signal having a frequency equal to said median frequency and phase reversal points occurring at a frequency equal to one-half the difference between the frequencies of said input signals; rectangular wave generating means connected to the output of said first adder means for generating a rectangular wave having leading and trailing edges in phase with the zero levels of said sum signal and having polarities in phase and equal to the polarities of said sum signal; delay means connected to the output of said rectangular wave generating means for delaying one-half cycle the output thereof; second adder means for linearly adding the outputs of said rectangular wave generating means and said delay means for producing a series of timing pulses; bistable multivibrator means including trigger means and a two-state complementary output means; said trigger means including a positive clipper means and a negative clipper means the input of each connected to the output of said second adder means; the output of said negative clipper means connected to the input of a first inverter means; a third adder means having one input connected to the output of said positive clipper means and a second input connected to the output of said inverter means; the output of said second adder means connected to the input of said two state complementary output means for changing the state thereof; and transmitting means including phase reversal means responsive to the outputs of said two state complementary output means for selectively inverting portions of said rectangular wave for transmitting said rectangular wave at said median frequency.

Claim 5

A device for generating an output signal having a frequency which is the median of the frequencies of a pair of original input signals comprising; first adder means for receiving said original input signals and for generating a sum signal having a frequency equal to said median frequency and phase reversal points occurring at a frequency equal to one-half the difference between the frequencies of said input signals; rectangular wave generating means connected to the output of said first adder means for generating a rectangular wave having leading and trailing edges in phase with the zero levels of said sum signal and having polarities in phase and equal to the polarities of said sum signal; delay means connected to the output of said rectangular wave generating means for delaying one-half cycle the output thereof; second adder means for linearly adding the outputs of said rectangular wave generating means and said delay means for producing a series of timing pulses; bistable multivibrator means including trigger means and a two-state complementary output means; said trigger means including a positive clipper means and a negative clipper means the input of each connected to the output of said second adder means; the output of said negative clipper means connected to the input of a first inverter means; a third adder means having one input connected to the output of said positive clipper means and a second input connected to the output of said inverter means; the output of said second adder means connected to the input of said two state complementary output means for changing the state thereof; and transmitting means including phase reversal means responsive to the outputs of said two state complementary output means for selectively inverting portions of said rectangular wave for transmitting said rectangular wave at said median frequency.