| import numpy as np |
| from detune_coeff_calc import rf_waveforms |
|
|
|
|
| class decay_slope: |
| def __init__(self, waveforms, acq_dt, n_pts=50, max_pw=500, verbose=False): |
| self.FWD_CPX = waveforms.get_ch("FWD_I") + 1j*waveforms.get_ch("FWD_Q") |
| self.CAV_CPX = waveforms.get_ch("CAV_I") + 1j*waveforms.get_ch("CAV_Q") |
| self.acq_dt = acq_dt |
| self.n_pts = n_pts |
| self.max_pw = max_pw |
| self.verbose = verbose |
|
|
| def _find_decay(self): |
| fwd = self.FWD_CPX |
| fwd_mag = abs(fwd) |
| fwd_max = max(fwd_mag) |
| fwd_end = max(np.nonzero(fwd_mag > 0.5*fwd_max)[0]) |
| if self.verbose: |
| print("find_decay: magnitude %.5f, end of pulse at %d" % (fwd_max, fwd_end)) |
| return fwd_end |
|
|
| def _set_start(self): |
| start = self._find_decay()+4 |
| fwd_len = len(self.FWD_CPX) |
| if start+self.n_pts > fwd_len: |
| start = fwd_len - self.n_pts |
| if start < self.n_pts or start > self.max_pw: |
| print("Aborting due to lack of reasonable trailing edge (%d)" % start) |
| exit(1) |
| if self.verbose: |
| print("Starting trailing waveform analysis at %d" % start) |
| return start |
|
|
| """ |
| arange for amplitude printout |
| prange for phase fitting (frequency offset) |
| drange for log amplitude fitting (decay time) |
| """ |
| def _calc_slope(self, arange, prange, drange): |
| cav = self.CAV_CPX |
| phase = np.angle(cav) |
| phase_unw = np.unwrap(phase[prange]) |
| ix = range(len(phase_unw)) |
| poly_fit = np.polyfit(ix, phase_unw, 1) |
| delta_f = poly_fit[0]/self.acq_dt/(2.0*np.pi) |
|
|
| amp = np.abs(cav) |
| amp_log = np.log(amp[drange]) |
| ix = range(len(amp_log)) |
| poly_fit = np.polyfit(ix, amp_log, 1) |
| bw = -poly_fit[0]/self.acq_dt/(2.0*np.pi) |
| max_amp = max(amp[arange]) |
| tup = bw, delta_f, max_amp |
| print("Measured bandwidth %.6f Hz, detune %.6f Hz, max amp %.5f" % tup) |
|
|
| return (delta_f, bw, max_amp) |
|
|
| def find_slope(self): |
| s = self._set_start() |
| return self._calc_slope(range(0, s), range(s, s+self.n_pts), range(s, s+self.n_pts)) |
|
|
|
|
| if __name__ == "__main__": |
| from argparse import ArgumentParser |
|
|
| parser = ArgumentParser(description="Approximate bandwidth and detune from decay waveform") |
| parser.add_argument("-f", "--datafile", dest="datafile", default=None, required=True, |
| help="IQ data input file") |
| parser.add_argument("-v", "--verbose", action="store_true", dest="verbose", help="Verbose mode") |
|
|
| args = parser.parse_args() |
|
|
| |
| rf_wvf = rf_waveforms(args.datafile, data_format=["UN_I", "UN_Q", |
| "FWD_I", "FWD_Q", |
| "REV_I", "REV_Q", |
| "CAV_I", "CAV_Q"]) |
|
|
| adc_clk = 1320.0e6 / 14.0 |
|
|
| |
| wvform_dt = (255*2*33) / adc_clk |
|
|
| slp = decay_slope(rf_wvf, wvform_dt, verbose=args.verbose) |
| slp.find_slope() |
|
|
