LCX_UserManual_en_08_1.pdf - 第77页

Instrument functions R&S ® LCX Series 77 User Manual 1 179.2260.02 ─ 08 measurement result. The cable length correction compensates these parasitic transmission characteristics. As a rule, make sure to keep the conne…

Instrument functions

R&S

LCX Series

76User Manual 1179.2260.02 ─ 08

[Auto].............................................................................................................................76

[Hold].............................................................................................................................76

[Trig.]............................................................................................................................. 76

[Auto]

Selects measurement function and the related default measurement pairs automati-

cally, according to the connected sample component.

For an overview of the impedance measurement parameters the R&S LCX provides,

see Section 5.2, "Impedance measurement parameters of the R&S LCX", on page 50.

Remote command:

FUNCtion:MEASurement:AUToselect on page 213

[Hold]

Freezes the currently set range.

When enabled, the R&S LCX displays the prefix "Hold:" at the range value.

Remote command:

FUNCtion:IMPedance:RANGe:HOLD on page 211

[Trig.]

Triggers one measurement cycle manually.

Remote command:

*TRG on page 185

TRIGger[:IMMediate] on page 243

8.6 Measurement parameters

The settings described in this section refer to parameters that you can configure for

your specific measurement in addition to the test signal, measurement mode, or mea-

surement functions.

About measurement parameters

Aspects on the measurement parameters:

●

Speed

The measurement speed defines the number of measurements in one second

when triggered continuously.

Impact of measurement speed and accuracy:

The measurement accuracy decreases with increasing speed, i.e. the higher the

number of measurements per second you perform, the lower the measurement

accuracy you can expect.

At low test signal frequencies, the R&S LCX reduces the measurement speed

automatically.

See "Speed" on page 80.

●

Cable length

Any cable covers inductive and capacitive parts, which depend in particular on the

cable length. As these characteristics are considered as parasitics, they distort a

Measurement parameters

Instrument functions

R&S

LCX Series

77User Manual 1179.2260.02 ─ 08

measurement result. The cable length correction compensates these parasitic

transmission characteristics.

As a rule, make sure to keep the connection between the R&S LCX and the com-

ponent under test as short as possible, even more, the length must not exceed

1 m.

When using test fixtures with cables, the cable length correction function reduces

the impact of cable losses to a minimum, and thus compensates the parasitic

transmission characteristics. See "Cable Length" on page 80 for the correspond-

ing setting.

●

Test signal type

The R&S LCX provides either the signal voltage or the signal current for setting the

test signal level, see "Test Signal Type" on page 80. If the signal current is

defined, the set value corresponds to the maximum current that flows when short-

circuited.

●

External voltage bias

See "Voltage Bias" on page 81.

●

Source impedance

By default, the R&S LCX measures with an output impedance of 100 Ω over the

entire measurement range ("High Z"). For certain applications, e.g., the measure-

ment of low-impedance components, you can set the output impedance to 10 Ω

("Low Z").

See "Source Impedance" on page 80.

●

Open/Short/Load correction

The numerous types of passive components with a wide variety of shapes require

suitable test fixtures, which in turn are equipped with or without test leads, clips or

probes, etc. As a result, measurement errors due to the test setup and used equip-

ment can occur. In particular, residual impedance, admittance, stray capacities or

environmental factors can impact the measurement.

Using the open/short/load correction technique, the R&S LCX compensates such

impacts.

For example, the open/short correction offsets residuals of test fixtures. For com-

plex errors, you can use the load correction function, which refers to a reference

component, e.g., a reference resistor. We recommend that you perform Open/Short

and Load correction when the measurement setup covers cable lengths other than

standard cables, user-specific test fixtures or additional passive circuits or compo-

nents, etc.

Open/Short/Spot corrections are always performed with the current measurement

settings (frequency, voltage, range, low Z/high Z, etc.). The measurement settings

are not changed for the measurement.

●

Spot correction

Note: To achieve the most accurate spot correction, we recommend that you per-

form all spot corrections in the "Auto" measurement range. The "Auto" range set-

ting selects the best measurement range for reading spot correction data with the

connected DUT. Running a spot correction with a manually selected measurement

range, or "Auto" range and "Hold", requires that you know the best measurement

range. Selecting an incorrect measurement range results in inaccurate correction

data and distorts the measurement results.

Measurement parameters

Instrument functions

R&S

LCX Series

78User Manual 1179.2260.02 ─ 08

In certain applications, you can apply the adjustment data of a spot correction to a

measurement with different settings. In this case, the R&S LCX displays the state

in different colors, see "Measurement status bar" on page 41.

Spot correction data is not applied, when you change the frequency, the cable

length, low Z/high Z or the voltage between ≤2 V and >2 V. The correction data of

the last spot correction remains persistent until a new adjustment is performed.

However, they are reset by default settings (reset), factory reset, or an instrument

restart.

●

Save/Restore correction data

The instrument provides internal memory slots to store and retrieve up to 10 cor-

rection data sets. You can save the data of all fully performed corrections (open/

short), i.e. spot and load correction data are excluded. The correction data remains

in the internal memory permanently. You can overwrite it by saving a new correc-

tion data set. A factory preset deletes the memory slots. However, correction data

sets of full corrections that are not saved explicitly remain persistent and are

restored with an instrument restart.

●

Auto function

The R&S LCX determines the component type of the DUT automatically, based on

the measured impedance and phase angle. The auto function allows you to set the

threshold values for the phase angle and the serial or parallel separation point.

The measurement principle distinguishes between pure and mixed measurement

pairs, i.e. measurement pairs with only real values (Rs-X,...), and measurement

pairs with additional imaginary components (LS-R).

Figure 5-1 under Measurement basics illustrates the relations.

See "Auto Function" on page 81.

8.6.1 Measurement parameter settings

The "Measurement" parameters define additional settings that relate, e.g., to the mea-

surement conditions.

Access:

1. Press the [settings] key at the front panel.

Measurement parameters