RF Sweep Signals

In an RF sweep measurement there is a requirement to estimate the current power of the different active sensors to support he feedback loop for power levelling, and to shut down in the event of unsafe power levels. To do this, the configuration for an RF sweep measurement requires you to define power signals. Power signals associate a type of power sensor with their associated instruments, data columns, and additional data required to estimate RF power like thermoelectric fit coefficients for thermo electric sensors, bias resistance for bolometers, or the AM modulation sensitivity for RF sources.

These signal configurations are used by both the measurement runner and the parser to identify which instruments and data columns are associated with what type of sensors.

Bolometers require a dc bias resistance to be specified, along with a bias_monitor instrument and its associated voltage column. This example shows the specification of a bolometer sensor as the DUT operating at 200 Ohms. A bolometer power signal requires input from a vdc (dc voltage) signal, voltage signal, which has it’s instrument,units, and data column specified.

Bolometer Signal

key_0	key_1	key_2	key_3	value	type	comment
signal_config	DUT_power	type		bolometer	str	sensor type of the DUT
signal_config	DUT_power	units		W	str	units should be W
signal_config	DUT_power	can_level		TRUE	bool	whether or not sensor can level
signal_config	DUT_power	resistance		200	float	resistance of the DUT
signal_config	DUT_power	input_signals		vdc	str	data signals used to estimat power
signal_config	DUT_power	vdc	units	V	str	units of input voltage
signal_config	DUT_power	vdc	column	DVM_volts	str	column name corresponding to voltage
signal_config	DUT_power	vdc	instrument	DVM1	str	instrument associated with this column

Thermoelectric sensors in a calorimeter or sensor require a voltage signal to process data. For thermoelectric signal, the coefficients are provided as an estimate of the linear sensitivity in units of \(\frac{\mathrm{V}}{\mathrm{W}}\) which is sufficient for the purposes of power levelling.

Thermoelectric Signal

key_0	key_1	key_2	key_3	value	type	comment
signal_config	calorimeter_power	type		thermoelectric	str	thermoelectric sensor of the calorimeter
signal_config	calorimeter_power	units		W	str	units produced from derived signal always W
signal_config	calorimeter_power	can_level		FALSE	bool	cant level to the calorimeter
signal_config	calorimeter_power	coeffs		0.033	float	voltage / W of the calorimeter’s thermopile (can be an estimate)
signal_config	calorimeter_power	input_signals		e	str	input signals from data record to derive calorimeter power estimate
signal_config	calorimeter_power	e	units	V	str	units of input signal
signal_config	calorimeter_power	e	column	NVM_volts	str	column corresponding to input signal
signal_config	calorimeter_power	e	instrument	NVM1	str	name of instrument associated with the signal

Some sensors may require multiple input quantities. For example, temperature dependent thermo electric sensors require a the voltage and current from a thermometer as an input, as well as tg voltage from a thermoelectric. Those can be specified as well.

Temperature Dependent Thermoelectric Signal

key_0	key_1	key_2	key_3	value	type	comment
signal_config	DUT_power	type		thermoelectric	str
signal_config	DUT_power	units		W	str
signal_config	DUT_power	can_level		TRUE	bool
signal_config	DUT_power	coeffs		0.2126	float
signal_config	DUT_power	input_signals		e	str
signal_config	DUT_power	input_signals		therm_i	str
signal_config	DUT_power	input_signals		therm_v	str
signal_config	DUT_power	e	units	V	str
signal_config	DUT_power	e	column	NVM_sensor_volts	str
signal_config	DUT_power	e	instrument	NVM1	str
signal_config	DUT_power	therm_i	units	A	str
signal_config	DUT_power	therm_i	column	therm_amps	str
signal_config	DUT_power	therm_i	instrument	SMU0	str
signal_config	DUT_power	therm_v	units	V	str
signal_config	DUT_power	therm_v	column	therm_volts	str
signal_config	DUT_power	therm_v	instrument	SMU0	str

RF Sources are commanded to output a power, but also may have there output power modulated by a Voltage Source acting as an rf_amplitude_adjuster.

RF Source with AM Signal

key_0	key_1	key_2	key_3	value	type	comment
signal_config	RF_source_power	type		RF_source	str	Type of signal for RF source is always RF source
signal_config	RF_source_power	units		W	str	units always W
signal_config	RF_source_power	can_level		FALSE	bool	whether signal can be levelled to
signal_config	RF_source_power	input_signals		vdc	str	input voltage signal from AM
signal_config	RF_source_power	input_signals		power	str	commanded power over GPIB
signal_config	RF_source_power	power	units	dBm	str	units of input power signal over GPIB always dBm
signal_config	RF_source_power	power	column	rf_power_setting	str	column where power originates
signal_config	RF_source_power	power	instrument	RF_source	str	instrument associated with column
signal_config	RF_source_power	vdc	units	V	str	units of input AM voltage signal
signal_config	RF_source_power	vdc	column	AM_voltage	str	column storing the AM voltage
signal_config	RF_source_power	vdc	instrument	RF_amplitude_adjuster	str	instrument associated with AM voltage signal