The Mode menu defines the properties of the physical and logical (balanced) test ports, configures the source signals and the receiver, and provides special measurement modes.
The items in the submenu depend on the analyzer type and on the installed options.
Port Config... opens a dialog to define the properties of the test ports, the source and the receiver.
ZVAX Path Config configures the RF signal paths in the Extension Unit R&S ZVAXxx and the installed hardware modules. The command is unavailable if no RZS ZVAXxx unit is connected.
Harmonics provides arbitrary harmonic distortion measurements including power calibration.
Scalar Mixer Meas measures the mixing products generated by an external mixer that is supplied with two independent RF signals.
Mixer Delay Meas gives access to the measurement of the absolute or relative group delay of a mixer.
Noise Figure Meas configures and activates the measurement of the noise figure of a DUT.
Virtual Transform defines the parameters of a virtual matching network to be used for embedding/deembedding a DUT with single ended or balanced ports.
Alternating Sweeps activates or deactivates the operating mode where the analyzer performs only one partial measurement per sweep.
Pulse Generator turns the pulse generator on or off.
Def Pulse Generator defines the properties of the pulse generator signals.
Spurious Avoidance defines the relative position of the local oscillator (LO) relative to the RF input signal.
ALC (All Chans) enables or disables the Automatic Level Control for all channels.
Low Phase Noise reduces the phase noise of the source signals.
The Port Configuration dialog defines the properties of the test ports and configures the source signals and the receiver.
The table in the Port Configuration dialog contains the individual test port properties. Each table row corresponds to one logical or physical port; the number of rows is equal to the number of test ports of the analyzer.
Many measurement tasks can be performed with default port settings. Consequently the Port Configuration dialog does not show all columns in its default configuration. Use the Displayed Columns button to customize the table and display or hide columns.
Measured Ports (Meas/Group)
The ports that can be used for the measurement (as selected in the Balanced Ports and Port Groupsdialog) are indicated in the first column of the Port Configuration table (Meas). The selected ports are used for the calculation of derived (mixed mode, Z, Y) parameters; they can be source ports and/or receive ports.
After an n-port (automatic or manual) system error correction, only the calibrated ports are enabled. It is possible though to re-enable uncalibrated ports manually in order to obtain additional (uncalibrated) measurement results. Loading a set of calibration data does not affect the selection of measured ports.
A measured port can be configured as a pure receive port by selecting RF Off in the Source section.
If one or more port groups to be measured are defined in the Define Measured Portstab of the Balanced Ports and Port Groups dialog, then the column header changes from Meas. to Group and the column shows the group names (capital letters).
The settings are grouped together in four sections:
Logical Port shows the properties of the balanced ports after they have been defined in the Balanced Port and Port Groups dialog. This section is hidden if no balanced ports are defined.
Physical Port shows and/or defines the properties of the physical (unbalanced) ports of the analyzer.
Source shows and/or defines the generator settings at each physical port of the analyzer.
Receiver defines the receiver settings at each physical port of the analyzer.
Below the table, three buttons open additional dialogs:
Displayed Columns... customizes the port configuration table by displaying or hiding columns.
Balanced Ports and Port Groups... selects a balanced port configuration and defines the reference impedances at the ports.
Stimulus modifies all sweep frequencies and powers in the active channel, based on an arbitrary frequency and power reference.
The dialog contains the following additional controls:
If Same Connector Type at All Ports is active, the connector types at all ports (but not necessarily their gender) are always adjusted to the current selection in the Connector column.
If Same Gender at All Ports is active, the connector genders at all ports (but not necessarily their types) are always adjusted to the current selection in the Connector column.
Measure Source Port Waves at qualifies whether the waves at each source port are measured at the selected receiver or source frequency. The setting affects both the reference receiver (waves an) and the measurement receiver (waves bn) while port n is used as a source port. Adjust the setting to the test setup and the measured quantity.
Freq Conv Off disables all power and frequency-converting modes, i.e. it disables frequency-converting measurements such as the Harmonics and the Mixer measurements (with option R&S ZVB-K3).
Remote control:
[SENSe<Ch>:]CORRection:COLLect:CONNection:PORTs ALL | SINGle [SENSe<Ch>:]CORRection:COLLect:CONNection:GENDers ALL | SINGle [SENSe<Ch>:]FREQuency:CONVersion:AWReceiver[:STATe]
Defines the properties of the logical (balanced) ports defined in the Balanced Port and Port Groups dialog. To display this section, at least one balanced port configuration must be defined and Logical Ports – Ref Impedance must be selected in the Displayed Columns dialog.
# is the port number of the logical port. This number is independent of the physical port numbers and of the ports that are combined to form a balanced port.
Ref Impedance shows the complex reference impedances of the ports.
Reference impedance settings
The default reference impedance for a physical port is equal to the reference impedance of the connector type assigned to the port but can be defined as an arbitrary complex value (renormalization of port impedances). By changing the reference impedance, it is possible to convert the measured values at 50 Ω (75 Ω) into values at arbitrary port impedances. For details refer to Virtual Transform –Reference Impedances.
For balanced ports it is possible to define separate complex reference impedances for differential and for common mode.
The default values for the balanced port reference impedances are derived from the default reference impedance of the physical analyzer ports (Z0 = 50 >Ω):
The default value for the differential mode is Z0d = 100 Ω = 2*Z0.
The default value for the common mode is Z0c = 25 Ω = Z0/2.
SENSe:PORT<phys_port>:ZREFerence <real> [,<imaginary] SENSe:LPORT<log_port>:ZCOMmon <real> [,<imaginary] SENSe:LPORT<log_port>:ZDIFferent <real> [,<imaginary] CALCulate<Chn>:TRANsform:IMPedance:RNORmal TWAVes | PWAVes
Shows and/or defines the properties of the physical (unbalanced) ports of the analyzer.
# is the test port number of the analyzer as shown on the front panel. External generators and power meters configured in the System Configuration dialog are also shown in the list of physical ports.
Instrum. shows the network analyzer type (e.g. ZVA8, ZVA24). The types of external generators and power meters are also displayed in this column.
Connector opens a drop-down list to select the connector type An (f) behind the connector type denotes female connectors, an (m) denotes male connectors. Symmetric (sexless) connectors (e.g. PC7) are not labeled. User-defined connectors can be added or removed in the Available Connector Types dialog, which is opened from the Channel –Calibration –Calibration Kits dialog. at the port and its gender. If Same Connector at All Ports is active, the connector types at all ports (but not their gender) are always adjusted to the current selection.
Ref. Impedance shows the adjustable complex reference impedances of the physical port. For background information refer to Reference Impedances. If a balanced port configuration is active the reference impedance settings for all ports are displayed in the Logical Port section. For external generators and frequency converters, no reference impedance settings are available. The reference impedance for external power meters must be real; no wave theory selection is required. If a value Re(Z0) other than 50 Ω is entered, the power result from the power meter is multiplied by the factor 50 Ω / Re(Z0) (conversion of the reported power to a voltage at 50 Ω, then re-conversion to a power using Re(Z0)).
To perform a system error correction, the physical port must be available as a source and receive port. This condition is met if it is selected as a measured port in the Balanced Ports and Port Groups dialog (Meas is on).
To perform a system error correction, it is necessary that:
the physical port is available as a source port
both the measurement and the reference channel at the port can be measured
These conditions are met with the Port Configuration settings listed below.
Section
Parameter
Value
Meas
On
on
Source
Perm
off
Receiver
LO a
LO b
[SENSe<Ch>:]CORRection:COLLect:CONNection<port_no> [SENSe<Ch>:]CORRection:COLLect:SCONnection<port_no> [SENSe<Ch>:]CORRection:COLLect:CONNection:PORTs ALL | SINGle SENSe:PORT<phys_port>:ZREFerence <real> [,<imaginary]
Shows and/or defines the RF generator settings for each physical port of the analyzer and for each external generator. No source settings are provided for external power meters.
RF Off switches the RF signal source at the port off (box checked) or on. Dependencies: The column is disabled (grayed) while the RF power is switched off globally for the active channel. The settings are restored as soon as the RF power is switched on again. RF Off and Meas are independent from each other: While the RF power is switched off, the port is not necessarily excluded from the measurement, it can still be used as a receive port. On the other hand, an excluded port (Meas = Off) can still be used as an RF signal source. The exact behavior of RF Off is part of the system configuration; refer to the description of the Power tab.
The source must be switched on to perform a system error correction or a source power calibration for the source port.
Frequency Result displays the current frequency range (for frequency sweeps) or CW frequency (for power, time and CW Mode sweeps); see stimulus parameters.
Power Result displays the current power range (for power sweeps) or fixed internal source power (for frequency, time and CW Mode sweeps); see stimulus parameters.
PCor Off enables or disables a source power calibration for an individual port. This function is available only for ports where a source power calibration is available. It is identical with Source Power Correction Off in the Source Power Cal menu.
Slope defines a linear factor to modify the port-specific source power as a function of the stimulus frequency. The Slope factor increases the power at each sweep point by the following amount: Power --> Power + <Slope>*<Stimulus Frequency>. Slope is valid for all sweep types.
ALC defines port-specific Automatic Level Control (ALC) settings (entries a1, a2 ...) or general ALC settings (entries Off).
Impact of the Slope
The channel base power pb is defined by the following sweep settings:
For a power sweep, the channel base power is equal to the stimulus range.
For a frequency or CW sweep, the channel base power is a fixed Powervalue.
The slope modifies the channel power pb so that the following source power ps is obtained at the ports:
ps = pb + <Slope> * f
In the formula above, f denotes the (current) source port frequency.
Examples:
1. Select a frequency sweep with a sweep range between 1 GHz and 4 GHz and set <Power> = 0 dBm, <Slope> = 2 dB/GHz. Across the sweep range, the stimulus power increases linearly between 2 dBm and 8 dBm.
2. Maintain the <Slope> setting and select a power sweep with a CW frequency of 1 GHz and a power sweep range between –25 dBm and 0 dBm. Due to the slope factor, the actual stimulus power varies between –23 dBm and +2 dBm.
[SENSe<Ch>:]FREQuency:STARt? [SENSe<Ch>:]FREQuency:STOP? [SENSe<Ch>:]SWEep:CW|FIXed? SOURce<Ch>:POWer[:LEVel][:IMMediate][:AMPlitude]? SOURce<Ch>:POWer<Pt>:CORRection[:STATe] SOURce<Ch>:POWer<Pt>[:LEVel][:IMMediate]:SLOPe
Shows and/or defines the receiver settings for each physical port of the analyzer and each external power meter. No receiver settings are provided for external generators.
PCor Off enables or disables a receiver power calibration for an individual port. This function is available only for ports where a receiver power calibration is available. It is identical with Receiver Power Correction Off in the Receiver Power Cal menu.
IF Gain b selects the IF gain in the measurement receiver path.
Receiver path settings and AGC
The IF Gain settings are valid for all ports:
Auto means that the analyzer adapts the IF gain to the RF input level (Automatic or Adaptive Gain Control, AGC). The A/D converter is always operated at optimum input level.
The following settings accelerate the measurement:
Low Dist(ortion) corresponds to a small IF gain(i.e. a lower internal A/D converter input level). This setting allows for a high RF overdrive reserve and is appropriate for high RF input levels.
Low Noise corresponds to a large IF gain(i.e. a higher internal A/D converter input level). This setting increases the dynamic range and is appropriate for low RF input levels.
The Low Dist or Low Noise settings are appropriate whenever the characteristics of the input path must be constant, e.g. because:
Interfering signal contributions originating from the receiver (noise, nonlinear contributions) must not change during the measurement.
A large interfering signal in the vicinity of the measured signal must not overdrive the receiver.
[SENSe<Ch>:]FREQuency:STARt? [SENSe<Ch>:]FREQuency:STOP? [SENSe<Ch>:]SWEep:CW|FIXed? [SENSe<Ch>:]CORRection:POWer[:STATe] [SENSe<Ch>:]POWer:IFGain:MEASure
The Port <n> Power dialog defines the target power for the calibrated source port.
The port-specific source power can be set to either the channel base power pb plus an offset or to a constant value. The coefficients of the linear relation between pb and the actual source power are entered in a dialog.
The Port <n> Power settings serve different purposes:
Port Power Offset defines a port-specific offset to the channel power, to be added to the step attenuator settings. The actual output power at the port is equal to the channel power Pb (Channel – Stimulus – Power) plus the Port Power Offset minus the Attenuator setting. It is equal to the Port Power Offset (in dBm) minus the Attenuator setting if 0 dBm is selected instead of Pb. For power sweep and the selection Pb, the actual port power varies across the sweep, for other configurations the port power is constant.
Attenuator defines the source step attenuator setting (with options R&S ZVABxx-B21); see Step Attenuators. If Auto is selected, the step attenuator is set such that it doesn't have to be switched over the entire sweep. The input field is unavailable and shows 0 dB if no generator step attenuator is installed.
Cal Power Offset is relevant for source power calibrations; see background information below. The parameter specifies a gain (positive values) or an attenuation (negative values) in the signal path between the source port and the calibrated reference plane. With a Cal Power Offset of n dB, the target power at the reference plane is equal to the actual output power at the port plus n dB. The Cal Power Offset has no impact on the source power.
Port <n> Power Result is the power at the reference plane of the power calibration (if available), considering all dialog settings, including the Cal Power Offset.
Use of an amplifier in the signal path
Assume that a DUT requires a constant input power of +35 dBm, and that the measurement path contains an amplifier with a 30 dB gain.
After a reset of the analyzer the channel power Pb is zero dBm. With a Port Power Offset of +5 dB at the calibrated source port and a Cal Power Offset of +30 dB, the source power calibration ensures that the constant input power of +35 dBm is maintained across the entire sweep range. The actual output power of the analyzer is +5 dBm.
Note that a power calibration with an appropriate Cal Power Offset will automatically prevent excess input levels at the DUT.
Relation between channel power and port powers
The actual output power at the ports (source power ps) is related to the channel power pb as follows:
ps = pb + c + <Slope> * f , if the pb radio button is selected ps = pb + <Slope> * f , if the 0 dBm radio button is selected
In the formulas above, f denotes the (current) source port frequency, c is the offset value entered in the Port <nr> Source Power dialog minus the Attenuator setting. The Slope parameter is set in the Sourcesection of the Port Configuration table.
Use the Stimulus dialog to change all port powers based on an arbitrary reference power. Use the ...Port Power Limits in the System Configuration – Power tab if you want to limit the source power at a physical port permanently.
The analyzer generates a warning if the power settings for one of the ports exceed the hardware limits. At the same time, bit no. 14 in the ...INTegrity:HARDware status register is set. Reduce or increase the power result until the warning disappears.
SOURce<Ch>:POWer<Pt>:CORRection:LEVel:OFFSet (for Cal Power Offset) SOURce<Ch>:POWer<Pt>:CORRection:GENerator<Gen>:LEVel:OFFSet (for Cal Power Offset)
This dialog enables individual Automatic Level Control (ALC) settings for the physical analyzer ports. The settings are a subset of the general ALC settings, accessed via Channel – Mode – ALC (All Chans).
The port-specific ALC settings overwrite the general ALC settings. E.g. with active ACL (All Chans), you can select Individual Settings for Physical Port 1 and uncheck ALC On. This disables the ALC at the physical analyzer port no. 1. The ALC at all other ports is still enabled.
SOURce<Ch>:POWer<Pt>:ALC:CONTrol SOURce<Ch>:POWer<Pt>:ALC[:STATe] SOURce<Ch>:POWer<Pt>:ALC:PIParameter SOURce<Ch>:POWer<Pt>:ALC:PIParameter:GAIN SOURce<Ch>:POWer<Pt>:ALC:PIParameter:ITIMe SOURce<Ch>:POWer<Pt>:ALC:CLAMp
This dialog customizes the Port Configuration table and displays or hides columns.
(Un)checking Logical Port, Source or Receiver displays (removes) the corresponding sections in (from) the Port Configuration table.
(Un)checking one of the second-level boxes displays (removes) the corresponding column in (from) the Port Configuration table.
The physical port number is always displayed. The logical port information is displayed only if a balanced port configuration is defined.
No command, display configuration only.
The Stimulus dialog modifies all sweep frequencies and powers in the active channel, based on an arbitrary frequency and power reference. The dialog is accessed from the Port Configuration dialog.
The Stimulus dialog can be opened from the context menu of the channel list.
The available sweep parameters depend on the Current Sweep Type (Channel – Sweep – Sweep Type) which is displayed below the title bar of the dialog.
Sweep Type
Frequency parameters
Power parameters
Lin. Frequency Log. Frequency
Start Stop
CW
Segmented Frequency
– (defined by the sweep segments)
Power
Time CW Mode
The frequencies and powers are displayed in two separate but analogous panels:
Enter & Display in the Frequency panel contains a list of the channel base frequency fb plus the source and receiver frequencies at all logical ports that depend on fb. The list includes the frequencies of external power meters and generators. Fixed source and receiver frequencies (see Converted Frequencies) are not in the list; they are not affected by the settings in the Stimulus dialog. For R&S ZVB analyzers, all frequencies and powers are coupled so that this selection has no effect.
Enter & Display in the Power panel contains a list of the channel base power pb plus the source and receiver powers at all logical ports that depend on pb. The list includes the powers of external power meters and generators. Fixed source and receiver powers (see Port-Specific Power) are not in the list; they are not affected by the settings in the Stimulus dialog. The selected stimulus axis appears in the channel list when the Port Configuration dialog is closed, e.g. Base Pwr. x dBm, Port 1 Pwr x dBm, Gen1 Pwr x dBm.
Start, Stop define the frequency/power sweep ranges; CW defines the fixed frequency/power.
Frequency and power definition in the Stimulus dialog
If the selected reference frequency or reference power is changed, the analyzer modifies all source and receiver frequencies/powers accordingly, leaving the frequency and power conversion formulas unchanged. The Stimulus dialog thus ensures that all system frequencies/powers can be modified consistently, based on an arbitrary reference frequency.
The power and frequency entries in the Stimulus dialog are unrestricted. A compatibility check is performed when the dialog is closed. Frequencies and powers beyond the analyzer's hardware limits are marked with a red input field in the calling Port Configuration dialog.
By default, all port frequencies/powers are referenced to the base frequency/power (Channel Base fb/Pb). If another port frequency or power, which was selected as a reference, becomes invalid (e.g. because it is set to a constant value), it is automatically replaced by the channel base frequency/power.
[SENSe<Ch>:]SWEep:AXIS:FREQuency [SENSe<Ch>:]SWEep:AXIS:POWer