def corrections(self,frequency):
assert self.amplifier == 'None (86205A)'
forwardCorrection = bridgeInsertionTransferAt(frequency)
reflectedCorrection = 1 / bridgeCouplingFactorAt(frequency)
return (forwardCorrection,reflectedCorrection)
def measure(self):
assert self.switchPlatform.checkPreset(self.amplifiers[self.amplifier.value]),'The switch platform is not in the {position} position'.format(position=self.amplifier.value)
result = DictResult()
generatorPower = self.rfGenerator.getPower()
frequency = self.rfGenerator.getFrequency()
switchAttenuation = PowerRatio(sqrt(frequency/Frequency(170,'GHz')),'dB') # 2 switches - cable - cable - 2 switches
# in the incident path, these losses cancel (same loss for DUT and incident power meter)
# in the reflected path, these losses appear (the signal suffers from two cables and twice the switch platform)
if self.amplifier.value == 'None':
forwardPower = generatorPower * bridgeInsertionTransferAt(frequency)
reflectedPower = self.wattMeter.getPower(2) / bridgeCouplingFactorAt(frequency)
# insertionLoss = PowerRatio(1.5,'dB') * switchAttenuation
# reflectedAttenuation = PowerRatio(16.0 + 0.6*sin(2*pi*frequency/Frequency(12,'GHz')),'dB')
#
# forwardPower = generatorPower / insertionLoss
# reflectedPower = self.wattMeter.getPower(2) * reflectedAttenuation * switchAttenuation
else:
if self.amplifier.value == 'Prana':
forwardAttenuation = PowerRatio(48.7 - 0.4*sin(2*pi*frequency/Frequency(1,'GHz')),'dB')
reflectedAttenuation = forwardAttenuation / PowerRatio(0.1,'dB')
elif self.amplifier.value == 'Milmega 1':
forwardAttenuation = PowerRatio(44.9 - 0.6*sin(2*pi*(frequency-Frequency(900,'MHz'))/Frequency(2,'GHz')),'dB')
reflectedAttenuation = forwardAttenuation * PowerRatio(0.4,'dB')
elif self.amplifier.value == 'Milmega 2':
forwardAttenuation = PowerRatio(43.6 - 0.6*sin(2*pi*(frequency-Frequency(1.9,'GHz'))/Frequency(4,'GHz')),'dB')
reflectedAttenuation = PowerRatio(44.4 - 1.1*sin(2*pi*(frequency-Frequency(1.9,'GHz'))/Frequency(4,'GHz')),'dB')
else:
raise ValueError, 'The switch platform is in an unsupported position.'
abPowers = self.wattMeter.getPower()
forwardPower = abPowers(1) * forwardAttenuation
reflectedPower = abPowers(2) * reflectedAttenuation * switchAttenuation
result.data = {'generator power':generatorPower,
'transmitted power':forwardPower-reflectedPower,
'forward power':forwardPower,
'reflected power':reflectedPower}
self.emitResult(result)
return result
def reflectedPower():
assert switchPlatform.preset == 'bridge'
return incidentPower() * PowerRatio(-6,'dB') * bridgeCouplingFactorAt(rfGenerator.getFrequency())
