Single sideband double quadrature modulator
AssigneeLucent Technologies Inc.
InventorKirk Burton Ashby
Life of this patent
Estimating the term…
Abstract
A method of and apparatus for effecting single sideband modulation which mixes and sums the quadrature and in-phase components of a baseband signal with the in-phase and quadrature components of an intermediate frequency (IF) signal to form in-phase and quadrature components of a sum signal having a frequency equal to the sum of the frequencies of the baseband and intermediate frequency signals and which mixes and sums the quadrature and in-phase components of an RF carrier signal with the in-phase and quadrature components of the sum signal to form a single-sideband signal.
Claims11
A method of effecting single sideband modulation, comprising the steps of
- a. mixing in-phase components of baseband and intermediate frequency signals;
- b. mixing quadrature components of the baseband and intermediate frequency signals;
- c. summing the results of mixing steps a and b;
- d. mixing an in-phase component of the baseband signal with a quadrature component of the intermediate frequency signal;
- e. mixing a quadrature component of the baseband signal with an in-phase component of the intermediate frequency signal;
- f. summing the results of mixing steps d and e;
- and
- g. mixing and summing the results of steps c and f with the in-phase and quadrature components of an RF signal to produce a single sideband output signal.
A method of effecting single sideband modulation, comprising the steps of:
- a. mixing and summing the quadrature and in-phase components of a baseband signal with the in-phase and quadrature components of an intermediate frequency (IF) signal to form in-phase and quadrature components of a signal having a frequency equal to the sum and difference of the baseband and intermediate frequency signals;
- and
- b. mixing and summing the quadrature and in-phase components of an RF carrier signal with the in-phase and quadrature components of said sum and difference signals to form a single-sideband signal.
A method of effecting single sideband modulation, comprising the steps of:
- a. forming two single sideband intermediate frequency signals that are in quadrature;
- b. filtering to remove unwanted harmonics of the intermediate frequency;
- c. multiplying the filtered intermediate frequency single sideband signals with phase shifted quadrature radio frequency signals to form a pair of product signals;
- and
- d. adding or subtracting the product signals to select the desired single sideband output.
A single sideband modulator architecture for generating a desired output frequency as the sum or difference of an IF local oscillator frequency and an RF oscillator to drive an output buffer with a single sideband signal without employing a highly accurate phase shifter at RF, comprising:
- a. mixing an in-phase component of a baseband signal with the in-phase component of an IF signal;
- b. mixing a quadrature component of the baseband signal with the quadrature component of the IF signal;
- c. summing the results of mixing steps a and b;
- d. mixing an in-phase component of the baseband signal with a quadrature component of the IF signal;
- e. mixing a quadrature component of the baseband signal with an in-phase component of the IF signal;
- f. summing the results of mixing steps d and e;
- and
- g. mixing and summing the results of steps c and f with an in-phase and a quadrature component of an RF signal to produce a single sideband signal.
A method of modulating a radio frequency signal with a baseband signal having in-phase and quadrature components, comprising:
- a. mixing each component of the baseband signal with each of a pair of phase-shifted components of an intermediate frequency signal to form two pairs of product signals;
- b. separately summing each pair of product signals to form a pair of modulated intermediate frequency signals;
- c. mixing each of the modulated intermediate frequency signals with phase-shifted components of a radio frequency signal;
- and
- d. summing the products of the modulated intermediate frequency signals and the phase shifted components of the radio frequency signal.
Apparatus for effecting single sideband modulation, comprising:
- a circuit for mixing and summing the quadrature and in-phase components of a baseband signal with the in-phase and quadrature components of an intermediate frequency (IF) signal to form in-phase and quadrature components of a signal having a frequency equal to the sum and difference of the baseband and intermediate frequency signals;
- and
- a circuit for mixing and summing the quadrature and in-phase components of an RF carrier signal with the in-phase and quadrature components of said sum and difference signals to form a single-sideband signal.
Integrated circuit apparatus for effecting single sideband modulation, comprising:
- a first mixer circuit adapted to mix in-phase components of baseband and intermediate frequency signals;
- a second mixer circuit adapted to mix quadrature components of the baseband and intermediate frequency signals;
- a first summer for summing the outputs of said first and second mixer circuits;
- a third mixer circuit adapted to mix an in-phase component of the baseband signal with a quadrature component of the intermediate frequency signal;
- a fourth mixer circuit adapted to mix a quadrature component of the baseband signal with an in-phase component of the intermediate frequency signal;
- a second summer for summing the outputs of said third and fourth mixer circuits;
- a fifth mixer circuit adapted to mix the output of said first summer with the in-phase component of an RF signal;
- a sixth mixer circuit adapted to mix the output of said second summer with the quadrature component of said RF signal;
- and
- a third summer for summing the outputs of said fifth and sixth mixer circuits to produce a single sideband output signal.
Dependencies are inferred from the claim text.