class Measurement(MeasurementBase):
params = {
'Vdss': Sweep([0.0]),
'Vg1s': Sweep([0.0]),
'Vg2s': Sweep([0.0]),
'commongate': Boolean(False),
'Rg1': 100e3,
'Rg2': 100e3,
'Rds': 22e3,
'stabilise_time': 0.05,
'comment': String(''),
'data_dir':
Folder(r'D:\MeasurementJANIS\Holger\KTW H5 2x3\2017-11-09 LHe')
}
observables = [
'Vg1', 'Vg1m', 'Ileak1', 'Vg2', 'Vg2m', 'Ileak2', 'Vds', 'Vdsm', 'Rs'
]
alarms = [
['np.abs(Ileak1) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Ileak2) > 1e-8', MeasurementBase.ALARM_CALLCOPS],
['np.abs(Vg1-Vg2)', MeasurementBase.ALARM_SHOWVALUE
] # useful if we just want to know how much voltage
# is applied between the two gates
]
def measure(self, data_dir, comment, Vdss, Vg1s, Vg2s, commongate, Rg1,
Rg2, Rds, stabilise_time, **kwargs):
print("===================================")
print("Starting acquisition script...")
# initialise instruments
try:
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
self.sourceVds = sourceVds = BiltVoltageSource(bilt,
"I1",
initialise=False)
self.sourceVg1 = sourceVg1 = BiltVoltageSource(bilt,
"I2",
initialise=False)
self.sourceVg2 = sourceVg2 = BiltVoltageSource(bilt,
"I3",
initialise=False)
self.meterVds = meterVds = BiltVoltMeter(bilt, "I5;C1", "2",
"Vdsm")
self.meterVg1 = meterVg1 = BiltVoltMeter(bilt, "I5;C2", "2",
"Vg1m")
self.meterVg2 = meterVg2 = BiltVoltMeter(bilt, "I5;C3", "2",
"Vg2m")
print("DC sources and voltmeters are set up.")
except:
print(
"There has been an error setting up DC sources and voltmeters."
)
raise
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
# prepare saving data
filename = timestamp + '_' + (comment if comment else '') + '.txt'
self.prepare_saving(os.path.join(data_dir, filename))
# loops
for Vds in Vdss:
sourceVds.set_voltage(Vds)
for Vg2 in Vg2s:
if not commongate:
sourceVg2.set_voltage(Vg2)
for Vg1 in Vg1s:
if self.flags['quit_requested']:
return locals()
sourceVg1.set_voltage(Vg1)
if commongate:
Vg2 = Vg1
sourceVg2.set_voltage(Vg1)
# stabilise
time.sleep(stabilise_time)
# measure
Vdsm = meterVds.get_voltage()
Vg1m = meterVg1.get_voltage()
Vg2m = meterVg2.get_voltage()
# do calculations
Ileak1 = (Vg1 - Vg1m) / Rg1
Ileak2 = (Vg2 - Vg2m) / Rg2
Rs = Rds * Vdsm / (Vds - Vdsm)
# save data
self.save_row(locals())
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVds.set_voltage(0.)
self.sourceVg1.set_voltage(0.)
self.sourceVg2.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'Vgs': Sweep([0.]),
'Vg0': 0.,
'Vchuck0': 10.,
'Vchuckmax': 30.,
'CapaRatio': 10.,
'Rg': 100e3,
'stabilise_time': 0.3,
'comment': String(''),
'data_dir': Folder(r''),
'use_vna': Boolean(True),
'init_bilt': Boolean(False),
'init_yoko': Boolean(False)
}
observables = ['Vg', 'Vgm', 'Vchuck', 'Ileak']
alarms = [
['np.abs(Ileak) > 1e-8', MeasurementBase.ALARM_CALLCOPS]
]
def measure(self, data_dir, Vgs, Vg0, Vchuck0, Vchuckmax, CapaRatio, Rg,
comment, stabilise_time, use_vna, init_bilt, init_yoko,
**kwargs):
print("===================================")
print("Starting acquisition script...")
# initialise instruments
try:
print("Setting up DC sources and voltmeters...")
bilt = Bilt('TCPIP0::192.168.0.2::5025::SOCKET')
if init_bilt:
# source (bilt, channel, range, filter, slope in V/ms, label):
self.sourceVg = sourceVg = BiltVoltageSource(bilt, "I1", "12", "1", 0.005, "Vg")
else:
self.sourceVg = sourceVg = BiltVoltageSource(bilt, "I1", initialise=False)
# voltmeter (bilt, channel, filt, label=None)
self.meterVg = meterVg = BiltVoltMeter(bilt, "I5;C1", "2", "Vgm")
# voltage source for chuck
self.yoko = yoko = Yoko7651("GPIB::3::INSTR", func="VOLT",
rang=30., slope=1.,
initialise=init_yoko, verbose=True)
print("DC sources and voltmeters are set up.")
except:
print("There has been an error setting up DC sources and voltmeters:")
raise
try:
print("Setting up VNA...")
vna = AnritsuVNA('GPIB::6::INSTR')
sweeptime = vna.get_sweep_time()
print("VNA is set up.")
except:
print("There has been an error setting up the VNA:")
raise
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
# prepare saving DC data
filename = timestamp + ('_'+comment if comment else '')
self.prepare_saving(os.path.join(data_dir, filename+'.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
try:
os.makedirs(spectra_fol)
except OSError as e:
if e.errno != errno.EEXIST:
raise
if vna.get_sweep_type() == 'FSEGM':
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
vna.dump_freq_segments(f)
for Vg in Vgs:
if self.flags['quit_requested']:
print("Stopping acquisition.")
return locals()
print("Setting Vg = {}".format(Vg))
# calculate new chuck voltage to keep field constant
# set Vg
sourceVg.set_voltage(Vg)
Vchuck = Vchuck0+CapaRatio*(Vg-Vg0)
if np.abs(Vchuck) <= Vchuckmax:
print("Set chuck voltage:", Vchuck)
yoko.set_voltage(Vchuck)
else:
print("Chuck voltage too high:", Vchuck)
print("Not changing chuck voltage.")
Vchuck = yoko.get_voltage()
# wait
time.sleep(stabilise_time)
# read voltages
Vgm = meterVg.get_voltage()
# do calculations
Ileak = (Vg-Vgm)/Rg
# save DC data
self.save_row(locals())
if use_vna:
# save VNA data
print("Getting VNA spectra...")
vna.single_sweep(wait=False)
# display sweep progress
progressbar_wait(sweeptime)
# make sure sweep is really done
while not vna.is_sweep_done():
time.sleep(0.5)
table = vna.get_table([1,2,3,4])
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp+'_Vg=%2.4f_Vchuck=%2.4f'%(Vg, Vchuck)+'.txt'
np.savetxt(os.path.join(spectra_fol, spectrum_file), np.transpose(table))
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)
self.yoko.set_voltage(0.)
class Measurement(MeasurementBase):
params = {
'sweep': Boolean(False),
'startpoint': 0.,
'direction': 1.,
'step': 1.,
'Ithresh': 3e-7,
'Vmax': 30,
'stabilise_time': 10,
'init': Boolean(True),
'use_vna': Boolean(True),
'comment': String(''),
'data_dir': Folder(r'D:\MeasurementJANIS\Holger\test')
}
observables = ['Vg', 'Vgm', 'Ileak']
alarms = []
def measure(self, step, startpoint, direction, Ithresh, Vmax, sweep,
stabilise_time, init, use_vna, data_dir, comment, **kwargs):
print("===================================")
print("Starting acquisition script...")
vna_string = ''
# initialise instruments
try:
print("----------------------------------------")
print("Setting up Keithley DC sources...")
self.sourceVg = sourceVg = K2400('GPIB::24::INSTR',
sourcemode='v',
vrang=200,
irang=10e-6,
slope=1,
initialise=init)
print("DC sources are set up.")
except:
print("There has been an error setting up DC sources.")
raise
if use_vna:
print("Setting up VNA...")
vna = AnritsuVNA('GPIB::6::INSTR')
sweeptime = vna.get_sweep_time()
if vna.get_sweep_type() != 'FSEGM':
raise Exception('Please use segmented frequency sweep')
# check if the RF power is the same on both ports and for all
# frequency segments
count = int(vna.query(':SENS:FSEGM:COUN?'))
vna_pow = None
for i in range(1, count + 1):
port1pow = float(
vna.query(':SENS:FSEGM{}:POW:PORT1?'.format(i)))
port2pow = float(
vna.query(':SENS:FSEGM{}:POW:PORT2?'.format(i)))
if vna_pow is None and port1pow == port2pow:
vna_pow = port1pow
elif vna_pow is not None and port1pow == port2pow and port1pow == vna_pow:
continue
else:
raise Exception(
"Please select the same power for all ports and frequency segments"
)
port1att = vna.get_source_att(1)
port2att = vna.get_source_att(2)
if port1att == port2att:
vna_pow -= port1att
else:
raise Exception(
"Please select the same attenuators for both ports")
vna_string = '_pwr={:.0f}'.format(vna_pow)
print("VNA is set up.")
# define name
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
filename = timestamp + vna_string + ('_' + comment if comment else '')
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# prepare saving DC data
self.prepare_saving(os.path.join(data_dir, filename + '.txt'))
if use_vna:
# prepare saving RF data
spectra_fol = os.path.join(data_dir, filename)
create_path(spectra_fol)
# save segmented frequency sweep data to file
with open(os.path.join(spectra_fol, 'VNAconfig'), 'w') as f:
vna.dump_freq_segments(f)
Vg = startpoint
def measure_point(Ithresh=np.inf):
print('Setting Vg=' + str(Vg) + ' V...')
sourceVg.set_voltage(Vg)
print('Stabilising...')
progressbar_wait(stabilise_time)
# measure
Vgm = sourceVg.get_voltage()
Ileak = sourceVg.get_current()
# save data
self.save_row(locals())
# save VNA data
if use_vna:
# save VNA data
print("Getting VNA spectra...")
vna.single_sweep(wait=False)
# display sweep progress
progressbar_wait(sweeptime)
# make sure sweep is really done
while not vna.is_sweep_done():
time.sleep(0.5)
table = vna.get_table([1, 2, 3, 4])
timestamp = time.strftime('%Y-%m-%d_%Hh%Mm%Ss')
spectrum_file = timestamp + '_Vg={:.3f}.txt'.format(Vg)
np.savetxt(os.path.join(spectra_fol, spectrum_file),
np.transpose(table))
return np.abs(Ileak) > Ithresh
# measure at 0 V
measure_point()
# sweep if requested
#╦direction = 1. # up
if direction not in [1., -1.]:
raise Exception("select valid direction 1. or -1.")
back_to_zero = False
decimals = int(max(1., -np.log10(step) + 1.))
while sweep:
if self.flags['quit_requested']:
return locals()
Vg = np.around(Vg + step * direction, decimals)
if np.abs(Vg) > Vmax:
print("Reached maximum voltage! Inverting sweep direction.")
if direction < 0. and Vg < 0.:
back_to_zero = True
direction = -direction
continue
leak = measure_point(Ithresh)
if leak:
if direction * Vg < 0.:
continue
if direction < 0. and Vg < 0.:
back_to_zero = True
direction = -direction
if np.abs(Vg) < 1e-12 and back_to_zero:
break
print("Acquisition done.")
return locals()
def tidy_up(self):
self.end_saving()
print("Driving all voltages back to zero...")
self.sourceVg.set_voltage(0.)