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Constant Output Power Control Block: CONSTPOUT

Symbol

Summary

CONSTPOUT allows you to set up a schematic such that the measurements are calculated normally, but the output power is constant for each sweep point. CONSTPOUT changes the input power (DC or RF) in order to achieve the specified output power. You need to specify the power measurement component and frequency indices. This element only works with the APLAC Harmonic Balance simulator.

Parameters

Name Description Unit Type Default
ID Element ID   PO1
IN ID of the source element   PORT_P1
OUT ID of the power measurement element   PORT_P2
POUT Target output level dBm -30
MEAS Target power type   Function of Harmonics
SOURCE_TYPE Source harmonic component that is allowed to change   HB
ERR Maximum allowed error in output power   0.01
*MAX_ITER Maximum number of iterations   100
*MIN Lower limit for the source value (relative to the normal value)   0
*MAX Upper limit for the source value (relative to the normal value)   10000
RESET Reset source nominal value at each sweep point   No

* indicates a secondary parameter

Parameter Details

IN: Specifies the ID of the input (source) element(s), the amplitude of which is modified. It is limited to sources and port elements. You can specify multiple sources by using a comma separated list (for example, {Port_P1, Port_P2}).

OUT: Specifies the ID of the output measurement element. The output measurement element can be a Port or P_METER3 element.

MEAS: Specifies the output power measurement function.

  • Function of Harmonics: Measures the power at the harmonic(s) specified in the FUNC parameter.

    • In APLAC syntax, "f1" means tone 1, "f2" means tone 2, and "f3" means tone 3, etc. Additionally, "2f1" means the second harmonic of tone 1, and "3f1" means the third harmonic of tone 1, etc.

    • The "P()" function means power at the specified tone. For instance, "P(f1)" means the power at tone 1 and P("f1")+P("f2") means the sum of power at tone 1 and tone 2.

    • Adding quotes around the tone specification is optional (i.e. P("f1") vs. P(f1)).

  • All Harmonics in Band: Measures the total power in a user-specified bandwidth in the LOWERFREQ and UPPERFREQ parameters.

MAXITER: Specifies the maximum number of optimization iterations for each sweep point that is used to achieve the constant output power.

MIN: Specifies the minimum scale factor applied to the source. The default value is 0; the same as -800 dBm, 0 W or 0 V based on the source.

MAX: Specifies the maximum scale factor applied to the source. The default value is 10 which is 10x the nominal voltage or 10x the nominal power based on the source.

NOTE: The Pout parameter can be swept, allowing you to measure the circuit characteristics at several constant output power levels simultaneously.

Dynamic Parameters

Dynamic parameters are parameters whose existence depends on the settings of the static parameters. The following is a list of all possible CONSTPOUT parameters, depending on the settings of MEAS.

Name Description Unit Type Default
LOWERFREQ Lower limit for frequency Frequency 0 GHz
UPPERFREQ Upper limit for frequency Frequency 1000 GHz
FUNC Target output power function, e. g. P("f1")+P("f2")   P("f1")

Layout

This element does not have an assigned layout cell. You can assign artwork cells to any element. See “Assigning Artwork Cells to Layout of Schematic Elements” for details.

Examples

SINGLE-TONE ANALYSIS, VARY SINGLE DC SOURCE

The following figure depicts a CONSTPOUT block set up to vary a DC source in a single-tone Harmonic Balance analysis. SOURCE_TYPE is set to DC, therefore CONSTPOUT only varies the DC component of the input power (the V1 source) to achieve the specified output power.

SINGLE-TONE ANALYSIS, VARY SINGLE AC SOURCE

The following figure depicts CONSTPOUT set up to vary an AC source in a single-tone Harmonic Balance analysis. SOURCE_TYPE is set to HB, therefore CONSTPOUT only varies the AC component of the input power (the PORT_P1 source) to achieve the specified output power.

TWO-TONE ANALYSIS, VARY SINGLE DC SOURCE

The following figure depicts CONSTPOUT set up to vary a DC source in a two-tone Harmonic Balance analysis. SOURCE_TYPE is set to DC, therefore CONSTPOUT only varies the DC component of the input power to achieve the specified output power. There are two fundamental tones in the circuit. Their total power is measured as shown in the following figure.

TWO-TONE ANALYSIS, VARY SINGLE AC SOURCE

The following figure depicts CONSTPOUT set up to vary an AC source in a two-tone Harmonic Balance analysis. SOURCE_TYPE is set to HB, therefore CONSTPOUT only varies the AC component of the input power to achieve the specified output power. There are two fundamental tones in the circuit. The total power of these tones is measured as shown in the following figure.

TWO-TONE ANALYSIS, VARY MULTIPLE AC SOURCES

The following figure depicts CONSTPOUT set up to vary multiple input AC sources in a two-tone Harmonic Balance analysis. SOURCE_TYPE is set to HB, therefore CONSTPOUT only varies the AC component of the two input power sources (Port_P1 and PORT_P2) to achieve the specified output power.

Examples

The following figure shows how to use the CONSTPOUT element in a schematic. In this example, the CONSTPOUT element is set up for 38 dBm constant output power. The PWRSMP element is connected in the schematic to measure the incident input power.

The following figure shows the power and efficiency for the previous schematic. Because the CONSTPOUT element is present in the schematic, the output power is held constant at 38 dBm. The input power and PAE are calculated at this output power.

If the same schematic is simulated without the CONSTPOUT element, it results in the following figure. In this case, the output power varies over the range of frequency and the input power is constant.

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