Ultra-wideband (UWB) residual sideband (RSB) calibration using bi-phase shift keying (BPSK) signal source

A method for radio frequency (RF) residual sideband (RSB) calibration, comprising:

• enabling a residual sideband (RSB) signal generation circuit;
• adjusting a first phase shifter in a signal generation circuit so that a receive (Rx) baseband (BB) in phase signal and a Rx BB quadrature signal have a similar amplitude;
• setting a second phase shifter to an initial code (dCT+/−Δ);
• selecting a first (in phase) local oscillator (LO) calibration signal (CAL_LO_I) at the RSB signal generation circuit;
• responsive to the in phase LO calibration signal (CAL_LO_I), measuring an Rx BB-I output of an in phase baseband filter (BBF I(t))(ITXIRX=Acos(θ)) and an Rx BB-Q output of a quadrature baseband filter (BBF Q(t))(ITXQRX=αAcos(θ−φ+90°));
• selecting a second (quadrature) local oscillator (LO) calibration signal (CAL_LO_Q) at the RSB signal generation circuit;
• responsive to the quadrature LO calibration signal (CAL_LO_Q), measuring the Rx BB-I signal output of the in phase baseband filter (BBF I(t))(QTXIRX=Acos(θ+ε−90°)) and the Rx BB-Q signal output of the quadrature baseband filter (BBF Q(t)) (QTXQRX=αAcos(θ+ε−φ));
• deriving an Rx I/Q phase error correction factor φc;
• deriving an Rx I/Q gain ratio αc;
• applying the Rx I/Q phase error correction factor φc and the Rx I/Q gain ratio αc to the Rx BB-I signal and to the Rx BB-Q signal to obtain a frequency independent compensation signal for input to a correction function (h(t));
• adjusting the second phase shifter to obtain an additional set of outputs from the in phase baseband filter (BBF I(t)) and the quadrature baseband filter (BBF Q(t));
• and
• combining an adjusted output of the in phase baseband filter (BBF I(t)) after the second phase shifter is adjusted to obtain an additional set of outputs from the in phase baseband filter (BBF I(t)) and the quadrature baseband filter (BBF Q(t)) with an output of the correction function (h(t)) to generate a frequency dependent compensated signal.

A device for performing radio frequency (RF) residual sideband (RSB) calibration, comprising:

• means for enabling a residual sideband (RSB) signal generation circuit;
• means for adjusting a first phase shifter in a signal generation circuit so that a receive (Rx) baseband (BB) in phase signal and a Rx BB quadrature signal have a similar amplitude;
• means for setting a second phase shifter to an initial code (dCT+/−Δ);
• means for selecting a first (in phase) local oscillator (LO) calibration signal (CAL_LO_I) at the RSB signal generation circuit;
• means responsive to the in phase LO calibration signal (CAL_LO_I) for measuring an Rx BB-I output of an in phase baseband filter (BBF I(t))(ITXIRX=Acos(θ)) and an Rx BB-Q output of a quadrature baseband filter (BBF Q(t))(ITXQRX=αAcos(θ−φ+90°));
• means for selecting a second (quadrature) local oscillator (LO) calibration signal (CAL_LO_Q) at the RSB signal generation circuit;
• means responsive to the quadrature LO calibration signal (CAL_LO_Q) for measuring the Rx BB-I output of the in phase baseband filter (BBF I(t)) (QTXIRX=Acos(θ+ε−90°)) and the Rx BB-Q output of the quadrature baseband filter (BBF Q(t))(QTXQRX=αAcos(θ+ε−φ));
• means for deriving an Rx I/Q phase error correction factor φc;
• means for deriving an Rx I/Q gain ratio αc;
• means for applying the Rx I/Q phase error correction factor φc and the Rx I/Q gain ratio αc to the Rx BB-I signal and to the Rx BB_Q signal to obtain a frequency independent compensation signal for input to a correction function (h(t));
• means for adjusting the second phase shifter to obtain an additional set of outputs from the in phase baseband filter (BBF I(t)) and the quadrature baseband filter (BBF Q(t));
• and
• means for combining an adjusted output of the in phase baseband filter (BBF I(t)) after the second phase shifter is adjusted to obtain an additional set of outputs from the in phase baseband filter (BBF I(t)) and the quadrature baseband filter (BBF Q(t)) with an output of the correction function (h(t)) to generate a frequency dependent compensated signal.

A system for radio frequency (RF) residual sideband (RSB) calibration, comprising:

• a complex (in phase/quadrature (I/Q)) signal receiver;
• a signal generator configured to generate a transmit (Tx) signal;
• a first phase shifter operably coupled to the signal generator, the first phase shifter configured to selectively process one of an in phase local oscillator (LO) signal and a quadrature LO signal to create an initial phase between receive in phase (I) and quadrature (Q) signals to create balanced I/Q signals;
• a first signal combiner configured to combine a receive (Rx) signal with the transmit (Tx) signal to generate a first combined signal;
• a second phase shifter configured to provide a selected phase shift to the first combined signal;
• and
• a complex downconverter configured to generate an in phase Rx signal and a quadrature Rx signal alternatively using the in phase LO signal and the quadrature LO signal to generate one or more signals indicative of relative Tx-Rx LO phase (θ), amplitude (A), Tx LO I/Q phase mismatch (ε), Rx I/Q amplitude mismatch (α), and Rx I/Q phase mismatch (φ) at the output of the complex receiver.