#### [SENSe<Ch>:]FREQuency...

This subsystem sets frequency-related parameters, especially the measurement and display ranges for the different sweep types, and controls the frequency-converting measurement modes (harmonic distortion
, mixer mode
, etc.).

The frequency ranges for the different instrument models are listed below:

| ZVA8 | ZVA24
Start, Stop | 300 kHz to 8 GHz | 300 kHz to 24 GHz
Center | > 300 kHz to < 8 GHz | > 300 kHz to < 24 GHz
Span | 10 mHz to 7,9997 GHz | 10 mHz to 23,9997 GHz

Command tree: [SENSe<Ch>:]FREQuency

:CENTer

:CONVersion

:ARBitrary

:AWReceiver

[:STATe]

:HARMonic

:ORDer

:RELative

:RPORt

:SPORt

:MIXer...

:CW|FIXed

:LPNoise

:MODE

:SBANd

:SPAN

:STARt

:STOP

Note: For a frequency sweep the range can be defined alternatively by a combination of Start/Stop frequencies or a Center frequency and Span. In fixed frequency mode (power sweep or Time/CW Mode; see [SENSe<Chn>:]FUNCtion[:ON]
) the measurement frequency is set by means of [SENSe<Ch>:]FREQuency:CW|FIXed
.

##### [SENSe<Ch>:]FREQuency:CENTer <center_frequency>

Defines the center of the measurement and display range for a frequency sweep.

<Ch> | Channel number. If unspecified the numeric suffix is set to 1.
<center_frequency> | Center frequency of the sweep.
Range [def. unit] | Depending on the instrument model [Hz]. The increment (parameters UP or DOWN) is 0.1 kHz.
*RST value | Center of the analyzer's maximum frequency range: (fMIN + fMAX)/2
SCPI, Command Types | Confirmed, command or query.
Example: | FUNC "XFR:POW:RAT B1, A2" Activate a frequency sweep and select the ratio B1/A2 as measured parameter for channel and trace no. 1. `FREQ:CENT 100MHz` Set center frequency to 100 MHz. `FREQ:SPAN 50000` Set frequency span to 50 kHz.

The measurement range defined by means of the center frequency and the current span ([SENSe<Ch>:]FREQuency:SPAN
) must not exceed the allowed frequency range of the analyzer. If necessary, the span is reduced to min (Center – fMIN, fMAX – Center).

##### [SENSe<Ch>:]FREQuency:CONVersion
FUNDamental | HARMonic | SHARmonic | THARmonic | MIXer

Enables the measurement of a harmonic or the fundamental signal for channel <Ch>.

Enabling a harmonics measurement also resets the measured quantity; see program example below.

<Ch> | Channel number.
FUNDamental | Measurement of the fundamental signal (no frequency-converting mode).
HARMonic | Harmonics measurement. The order of the measured harmonic, the source port, and the receive port must be selected using the [SENSe<Ch>:]FREQuency:CONVersion:HARMonic... commands; see example below.
SHARmonic | THARmonic | Measurement of the 2nd or 3rd harmonic with source port 1 and receive port 2. These parameters have been introduced for compatibilty with the ZVR. While they are active, a query returns HARM.
MIXer | Mixer mode. The mixer mode is configured using the [SENSe<Ch>:]FREQuency:CONVersion:MIXer... commands.
*RST value | FUNDamental
SCPI, Command Types | Device-specific, command or query. Returned values: FUND or HARM.
Example: | *RST; FREQ:STAR 0.5E+9; STOP 1E+9 Reset the analyzer (activating a frequency sweep) and set the sweep range between 1 GHz and 1.1 GHz. FREQ:CONV:HARM:ORD 4; SPOR 1; RPOR 2 Configure a 4th harmonic measurement with source port 1 and receive port 2. The measurement is still not enabled. FREQ:CONV HARM Enable the configured harmonic measurement. CALC:PAR:MEAS? "TRC1" Query the measured quantity. The analyzer measures the wave quantity b2, the response is 'B2D1SAM'. FREQ:CONV:HARM:RELative ON Enable the relative harmonic measurement, creating a new channel and a new trace Trc2. CALC2:PAR:MEAS? "TRC2" Query the measured quantity in the new channel no. 2. The analyzer still measures the wave quantity b2, the response is 'B2D1SAM'. CALC2:MATH:STAT? Check whether the active trace in channel no. 2 (i.e. Trc2) is a mathematical trace: the response is 1.

##### [SENSe<Ch>:]FREQuency:CONVersion:ARBitrary
<numerator>, <denominator>, <offset>, CW | FIXed | SWEep

Defines the receiver frequency for frequency-converting measurements. The receiver frequency is either a range (for frequency sweeps) or a CW frequency (for power, time and CW Mode sweeps). The receiver frequency is valid for all ports.

<Ch> | Channel number.
<numerator> <denominator> <offset> | Parameters of the frequency formula. The receiver frequency fr is calculated according to fr = <numerator>/<denominator>*fb. + <offset> where fb represents the sweep range (for frequency sweeps, parameter SWEep). For power, time and CW Mode sweeps (parameters CW or FIXed), fb = 0. The conversion formula for fr is ZVR-compatible but differs from manual control where the ratio <numerator>/<denominator> also multiplies the <offset>.
Range [def. unit] | The converted frequency or frequency range must be within the analyzer's frequency range, depending on the instrument model [Hz]. In addition the following restrictions apply: <numerator> – Values are rounded to positive or negative integer numbers; zero is not allowed [1] <denominator> – Values are rounded to positive integer numbers [1] <offset> – Values are rounded to (positive or negative) multiples of 1 Hz [Hz].
*RST value | The default frequency/frequency range corresponds to the sweep range or CW frequency of the analyzer, i.e. <numerator> = <denominator> = 1 <offset> = 0 Hz
Sweep type Parameters | SWEep – A frequency sweep is active, the command defines a frequency range. CW | FIXed – A power, time or CW Mode sweeps is active, the command defines a fixed frequency.
*RST value | SWEep
SCPI, Command Types | Device-specific, command or query.
Example: | *RST; FREQ:STAR 1E+9; STOP 1.1E+9 Reset the analyzer (activating a frequency sweep) and set the sweep range between 1 GHz and 1.1 GHz. SENS:FREQ:CONV:ARB 2, 1, 1E+9, SWE Convert the receiver frequency to the range between 3 GHz and 3.2 GHz.

##### [SENSe<Ch>:]FREQuency:CONVersion:AWReceiver[:STATe] <Boolean>

Qualifies whether a waves are measured at the source or at the receiver frequency. The setting is relevant for all frequency-converting measurements.

<Ch> | Channel number.
<Boolean> | OFF - Measurement at source frequency ON - Measurement at receiver frequency
*RST value | OFF
SCPI, Command Types | Device-specific, command or query.
Example: | FREQ:CONV:AWR ON Measure a waves at the receiver frequency.

##### [SENSe<Ch>:]FREQuency:CONVersion:HARMonic:ORDer <order>

Selects the order of the harmonic measured if a harmonic measurement is enabled ([SENSe<Ch>:]FREQuency:CONVersion HARMonic
).

<Ch> | Channel number.
<order> | Order of the harmonic, integer multiple of the fundamental frequency measured.
Range [def. unit] | 2 to 100 [–].
*RST value | 2
SCPI, Command Types | Device-specific, command or query.
Example: | `See [SENSe<Ch>:]FREQuency:CONVersion`

##### [SENSe<Ch>:]FREQuency:CONVersion:HARMonic:RELative <Boolean>

Enables or disables the relative harmonic measurement where the harmonic is divided by the fundamental wave.

With enabled relative measurement the analyzer creates a new channel and a new (mathematical) trace; see program example for `[SENSe<Ch>:]FREQuency:CONVersion
`.

<Ch> | Channel number.
<Boolean> | Enable (ON) or disable (OFF) the relative harmonic measurement.
*RST value | OFF
SCPI, Command Types | Device-specific, command or query.
Example: | `See [SENSe<Ch>:]FREQuency:CONVersion`

##### [SENSe<Ch>:]FREQuency:CONVersion:HARMonic:RPORt <port_no>

Selects the receive port for the harmonic measurement.

<Ch> | Channel number.
<port_no> | Integer port number.
Range [def. unit] | Depending on the analyzer model [–].
*RST value | 2
SCPI, Command Types | Device-specific, command or query.
Example: | `See [SENSe<Ch>:]FREQuency:CONVersion`

##### [SENSe<Ch>:]FREQuency:CONVersion:HARMonic:SPORt <port_no>

Selects the source port for the harmonic measurement.

<Ch> | Channel number.
<port_no> | Integer port number.
Range [def. unit] | Depending on the analyzer model [–].
*RST value | 1
SCPI, Command Types | Device-specific, command or query.
Example: | `See [SENSe<Ch>:]FREQuency:CONVersion`