General Amplifier

Model nonlinear amplifier described by object or file data

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Libraries:
RF Blockset / Equivalent Baseband / Amplifiers

Description

The General Amplifier block models the nonlinear amplifier described by a data source. The data source consists of either an RF Toolbox™ data (rfdata.data) object or data from a file.

Parameters

Main

Data source — Data source that describes the amplifier behavior

Data file (default) | RFDATA object

Data source that describes the amplifier behavior, specified as a Data file or an RFDATA object.

Data file — Name of file that contains amplifier data

default.s2d (default) | string | character vector

Name of file that contains the amplifier data, specified as a string or a character vector. The file name must include the extension. If the file is not in your MATLAB^® path, specify the full path to the file or click the Browse button to find the file.

Dependencies

To enable this parameter, choose Data file in Data source.

RFDATA object — RF data object that contains amplifier data

read(rfdata.data, 'default.amp') (default) | rfdata.data object

RF data object that contains the amplifier data, specified as an RF Toolbox rfdata.data object, an RF toolbox command that creates the rfdata.data object, or a MATLAB expression that generates such an object.

Interpolation method — Method to interpolate network parameters

Linear (default) | Spline | Cubic

Method to interpolate the network parameters, specified as one of the following:

Method	Description
Linear	Linear interpolation
Spline	Cubic spline interpolation
Cubic	Piecewise cubic Hermite interpolation

Noise Data

Noise type — Type of noise data

Noise figure (default) | Spot noise data | Noise factor | Noise temperature

Type of noise data, specified as one of the following:

• Noise figure

• Spot noise data

• Noise factor

• Noise temperature

This parameter is disabled if the data source contains noise data.

Noise figure (dB) — Available signal-to-noise ratio at the input to available signal-to-noise ratio at the output

0 (default) | scalar ratio | vector of ratios

Available signal-to-noise ratio at the input to available signal-to-noise ratio at the output, specified as a scalar ratio or a vector of ratios.

Dependencies

To enable this parameter, select Noise figure in Noise type.

Minimum noise figure — Minimum ratio of available signal-to-noise ratio at input to available signal-to-noise ratio at output

0 (default) | scalar ratio | vector of ratios

Minimum ratio of available signal-to-noise ratio at the input to available signal-to-noise ratio at the output, specified as a scalar ratio or a vector of ratios.

Dependencies

To enable this parameter, select Spot noise data in Noise type.

Optimal reflection coefficient — Optimal source impedance

1+0i (default) | complex scalar | complex vector

Optimal source impedance, specified as a complex scalar or a complex vector.

Dependencies

To enable this parameter, select Spot noise data in Noise type.

Equivalent normalized noise resistance — Normalized resistance values used to take noise measurement

1 (default) | positive scalar | positive vector

Normalized resistance values used to take noise measurement, specified as a positive scalar or a positive vector.

Dependencies

To enable this parameter, select Spot noise data in Noise type.

Noise factor — Ratio of available signal-to-noise power at input to available signal-to-noise power at output

1 (default) | scalar ratio | vector of ratios

Ratio of available signal-to-noise power at the input to available signal-to-noise power at the output, specified as a scalar ratio or a vector of ratios.

Dependencies

To enable this parameter, select Noise factor in Noise type.

Noise temperature (K) — Equivalent temperature that produces the same amount of noise as amplifier

0 (default) | nonnegative scalar | nonnegative vector

Equivalent temperature that produces the same amount of noise as the amplifier, specified as a nonnegative scalar in kelvins or nonnegative vector with each element unit in kelvins.

Dependencies

To enable this parameter, select Noise temperature in Noise type.

Frequency (Hz) — Domain of frequencies to express noise data

2.0e9 (default) | nonnegative scalar | nonnegative vector

Domain of frequencies to express noise data, specified as a nonnegative scalar in hertz or nonnegative vector with each element unit in hertz. If you provide a scalar value for your noise data, the block ignores the Frequency (Hz) parameter and uses the same noise data for all frequencies. If you provide a vector of values for your noise data, it must be the same size as the vector of frequencies. The block uses the Interpolation method specified in the Main tab to interpolate noise data.

Nonlinearity Data

IP3 type — Type of third order intercept

OIP3 (default) | IIP3

Type of third order intercept, specified as OIP3 (output intercept point) or IIP3 (input intercept point). This parameter is disabled if the data source contains power data or IP3 data.

IP3 (dBm) — IP3 value

inf (default) | scalar | vector

IP3 value, specified as a scalar in dBm for frequency independent nonlinear data or a vector with each element unit in dBm for frequency dependent nonlinear data. This parameter is disabled if the data source contains power data or IP3 data.

1dB gain compression power (dBm) — Output power value at which gain has decreased by 1 dB

inf (default) | scalar | vector

Output power value ($$P_{1dB,out}$$) at which the gain has decreased by 1 dB, specified as a scalar in dBm for frequency independent nonlinear data or vector with each element unit in dBm for frequency dependent nonlinear data. This parameter is disabled if the data source contains power data or IP3 data.

Output saturation power (dBm) — Output power value that amplifier produces when fully saturated

inf (default) | scalar | vector

Output power value ($$P_{sat,out}$$) that the amplifier produces when fully saturated, specified as a scalar in dBm for frequency independent nonlinear data or a vector with each element unit in dBm for frequency dependent nonlinear data. This parameter is disabled if the data source contains output saturation power data.

Gain compression at saturation (dB) — Decrease in gain value

3 (default) | scalar | vector

Decrease in gain value ($$G{C}_{sat}$$) when the power is fully saturated, specified as a scalar in dB for frequency independent nonlinear data or a vector with each element unit in dB for frequency dependent nonlinear data.

Frequency (Hz) — Frequency points corresponding to third-order intercept or power data

2.0e9 (default) | positive scalar | positive vector

Frequency points corresponding to third-order intercept or power data, specified as a positive scalar or positive vector in units of hertz. This parameter is disabled if the data source contains power data or IP3 data.

Dependencies

• If you specify the frequency as a scalar, then the IP3 (dBm), 1 dB gain compression power (dBm), and Output saturation power (dBm) parameters must all be scalars.

• If you specify the frequency as a vector, then or more of the IP3 (dBm), 1 dB gain compression power (dBm), and Output saturation power (dBm) parameters must also be a vector.

Visualization

Source of frequency data — Frequency data source

Extracted from data source (default) | User-specified

Frequency data source, specified as Extracted from data source or User-specified.

Frequency data (Hz) — Frequency data range

[1e9:1e8:2.9e9] (default) | vector

Frequency data range, specified as a vector with each element unit in hertz.

Dependencies

To enable this parameter, set Source of frequency data to User specified.

Source of input power — Input power source

User-specified (default) | Extracted from data source

Input power source, specified as Extracted from data source or User-specified. This parameter is disabled if the data source contains power data.

Input power data (dBm) — Input power data range

[0:19] (default) | vector

Input power data range, specified as a vector with each element unit in dBm. This parameter is disabled if the data source contains power data.

Reference impedance (ohms) — Reference impedance

50 (default) | nonnegative scalar

Reference impedance, specified as a nonnegative scalar in ohms.

Plot type — Type of data plot

X-Y plane (default) | Composite data | Polar plane | Z Smith chart | Y Smith chart | ZY Smith chart

Type of data plot to visualize using the given data, specified as one of the following:

• X-Y plane — Generate a Cartesian plot of the data versus frequency. To create linear, semilog, or log-log plots, set the Y-axis scale and X-axis scale accordingly.

• Composite data — Plot the composite data. For more information, see Create Plots Using Equivalent Baseband Library Blocks.

• Polar plane — Generate a polar plot of the data. The block plots only the range of data corresponding to the specified frequencies.

• Z smith chart, Y smith chart, and ZY smith chart — Generate a Smith^® chart. The block plots only the range of data corresponding to the specified frequencies.

Y parameter1 — Type of parameters to plot

S11 (default) | S12 | S21 | S22 | GroupDelay | OIP3 | IIP3 | NF | ...

Type of parameters to plot based on the Plot type you set, specified as one of the following.

Plot type	Y parameter1
X-Y plane	For X-Y plane data plot, Y parameter1 varies based on Data source you select. For more information, see Parameters to plot in X-Y pane.
Composite data	No Y parameter1 to set.
Polar plane	S11, S12, S21, and S22
Z Smith chart	S11 and S22.
Y Smith chart	S11 and S22.
ZY smith chart	S11 and S22.

Y parameter2 — Type of parameters to plot

S11 (default) | S12 | S21 | S22 | GroupDelay | OIP3 | IIP3 | NF | ...

Type of parameters to plot based on the Plot type you set, specified as one of the following.

Plot type	Y parameter2
X-Y plane	For X-Y plane data plot, Y parameter2 varies based on Data source you select. For more information, see Parameters to plot in X-Y pane.
Composite data	No Y parameter1 to set.
Polar plane	S11, S12, S21, and S22
Z Smith chart	S11 and S22.
Y Smith chart	S11 and S22.
ZY smith chart	S11 and S22.

Y format1 — Plot format

Magnitude (decibels) (default) | Mag | Magnitude (linear) | Angle | Real | Imaginary | ...

Plot format, specified as one of the following.

Y parameter1	Y format1
S11, S12, S21, S22, GammaIn, GammaOut, GammaOPT, TF1, TF2, TF3, GammaMS, GammaML, and Delta.	dB, Magnitude (decibels), Abs, Mag, Magnitude (linear), Angle, Angle(degrees), Angle(radians), Real, Imag, and Imaginary.
GroupDelay	ns, us, ms, s, and ps.
AM/AM, VSWRIn, and VSWROut.	dB, Magnitude (decibels), and None.
Pout, OIP3, and IIP3.	dBm, dBW, W, and mW.
NF	dB and Magnitude (decibels).
RN, NFactor, K, Mu, and MuPrime.	None
NTemp	Kelvin
Fmin, Gt, Ga, Gp, Gmag, and Gmsg.	dB, Magnitude (decibels), and None.
Phase and AM/PM	Angle, Angle(degrees) , and Angle(radians).

Dependencies

To enable Y format1, set Plot type to X-Y plane.

Y format2 — Plot format

Magnitude (decibels) (default) | Mag | Magnitude (linear) | Angle | Real | Imaginary | ...

Plot format, specified as one of the following.

Y parameter2	Y format2
S11, S12, S21, S22, GammaIn, GammaOut, GammaOPT, TF1, TF2, TF3, GammaMS, GammaML, and Delta.	dB, Magnitude (decibels), Abs, Mag, Magnitude (linear), Angle, Angle(degrees), Angle(radians), Real, Imag, and Imaginary.
GroupDelay	ns, us, ms, s, and ps.
AM/AM, VSWRIn, and VSWROut.	dB, Magnitude (decibels), and None.
Pout, OIP3, and IIP3.	dBm, dBW, W, and mW.
NF	dB and Magnitude (decibels).
RN, NFactor, K, Mu, and MuPrime.	None
NTemp	Kelvin
Fmin, Gt, Ga, Gp, Gmag, and Gmsg.	dB, Magnitude (decibels), and None.
Phase and AM/PM	Angle, Angle(degrees) , and Angle(radians).

Dependencies

To enable Y format2, set Plot type to X-Y plane.

X parameter — Frequency plot

Freq (default) | AM

Frequency plot, specified as Freq or AM.

Dependencies

To set X parameter to AM, you must set Y parameter1 to AM/AM or AM/PM.

X format — Frequency plot format

Hz (default) | Auto | kHz | MHz | GHz | THz | ...

Frequency plot format, specified as one of the following.

X parameter	X format
Freq	Auto, Hz, kHz, MHz, GHz, and THz.
AM	Magnitude (decibels), Magnitude (linear), dB, Mag, and None.

Y scale — Y-axis scale

Linear (default) | Log

Y-axis scale, specified as Linear or Log.

Dependencies

To enable this parameter, set Plot type to X-Y plane.

X scale — X-axis scale

Linear (default) | Log

X-axis scale, specified as Linear or Log.

Dependencies

To enable this parameter, set Plot type to X-Y plane.

Plot — Plot specified data

button

Plot specified data using the plot button.

Operating Conditions

Agilent^® P2D and S2D files define block parameters for several operating conditions. Operating conditions are the independent parameter settings that are used when creating the file data. By default, RF Blockset™ Equivalent Baseband software defines the block behavior using the parameter values that correspond to the operating conditions that appear first in the file. To use other property values, you must select a different operating condition in the General Amplifier block dialog box.

Bias — Amplifier bias

1.9 (default) | scalar

Amplifier bias, specified as a scalar in volts. This parameter is set to 1.9 volts when the Data file is default.s2p.

More About

Network Parameters

If network parameter data and corresponding frequencies exist as S-parameters in the data source, the General Amplifier block interpolates the S-parameters to determine their values at the modeling frequencies. If the network parameters are Y- or Z-parameters, the block first converts them to S-parameters. For more information, see Map Network Parameters to Modeling Frequencies.

Nonlinearity

If power data exists in the data source, the block extracts the AMAM/AMPM nonlinearities from the power data.

If the data source contains no power data, then you can introduce nonlinearities into your model by specifying parameters in the Nonlinearity Data tab of the General Amplifier block dialog box. Depending on which of these parameters you specify, the block computes up to four of the coefficients $$c_1$$, $$c_3$$, $$c_5$$, and $$c_7$$ of the polynomial

$$F_{AM/AM}(s)=c_{1}s+c_3{\left|s\right|}^{2}s+c_5{\left|s\right|}^{4}s+c_7{\left|s\right|}^{6}s$$

that determines the AM/AM conversion for the input signal $$s$$. The block automatically calculates $$c_1$$, the linear gain term. If you do not specify additional nonlinearity data, the block operates as a linear amplifier. If you do, the block calculates one or more of the remaining coefficients as the solution to a system of linear equations, determined by the following method.

1. The block checks whether you have specified a value other than Inf for:

   • The third-order intercept point ($$OIP3$$ or $$IIP3$$).

   • The output power at the 1-dB compression point ($$P_{1dB,out}$$).

   • The output power at saturation ($$P_{sat,out}$$).

   In addition, if you have specified $$P_{sat,out}$$, the block uses the value for the gain compression at saturation ($$G{C}_{sat}$$). Otherwise, $$G{C}_{sat}$$ is not used. You define each of these parameters in the block dialog box, on the Nonlinearity Data tab.

2. The block calculates a corresponding input or output value for the parameters you have specified. In units of dB and dBm,

   $$\begin{array}{c}{P}_{sat,out}+G{C}_{sat}=P_{sat,in}+G_{lin}\\ P_{1dB,out}+1=P_{1dB,in}+G_{lin}\\ OIP3=IIP3+G_{lin}\end{array}$$

   where $$G_{lin}$$ is $$c_1$$ in units of dB.

3. The block formulates the coefficients $$c_3$$, $$c_5$$, and $$c_7$$, where applicable, as the solutions to a system of one, two, or three linear equations. The number of equations used is equal to the number of parameters you provide. For example, if you specify all three parameters, the block formulates the coefficients according to the following equations:

   $$\begin{array}{c}\sqrt{P_{sat,out}}=c_1\sqrt{P_{sat,in}}+c_3{\left(\sqrt{P_{sat,in}}\right)}^3+c_5{\left(\sqrt{P_{sat,in}}\right)}^5+c_7{\left(\sqrt{P_{sat,in}}\right)}^7\\ \sqrt{P_{1dB,out}}=c_1\sqrt{P_{1dB,in}}+c_3{\left(\sqrt{P_{1dB,in}}\right)}^3+c_5{\left(\sqrt{P_{1dB,in}}\right)}^5+c_7{\left(\sqrt{P_{1dB,in}}\right)}^7\\ 0=\frac{c_1}{IIP3}+c_3\end{array}$$

   The first two equations are the evaluation of the polynomial $$F_{AM/AM}(s)$$ at the points $$(\sqrt{P_{sat,in}},\sqrt{P_{sat,out}})$$ and $$(\sqrt{P_{1dB,in}},\sqrt{P_{1dB,out}})$$, expressed in linear units (such as W or mW) and normalized to a 1-Ω impedance. The third equation is the definition of the third-order intercept point.

   The calculation omits higher-order terms according to the available degrees of freedom of the system. If you specify only two of the three parameters, the block does not use the equation involving the parameter you did not specify, and eliminates any $$c_7$$ terms from the remaining equations. Similarly, if you provide only one of the parameters, the block uses only the solution to the equation involving that parameter and omits any $$c_5$$ or $$c_7$$ terms.

If you provide vectors of nonlinearity and frequency data, then the block calculates the polynomial coefficients using values for the parameters interpolated at the center frequency.

Active Noise

You can specify active block noise in one of the following ways:

• Spot noise data in the data source.

• Spot noise data in the block dialog box.

• Spot noise data object in the block dialog box.

• Noise figure, noise factor, or noise temperature value in the block dialog box.

• Frequency-dependent noise figure data (rfdata.nf) object in the block dialog box.

The latter four options are only available if noise data does not exist in the data source.

If you specify block noise as spot noise data, the block uses the data to calculate noise figure. The block first interpolates the noise data for the modeling frequencies, using the specified Interpolation method. It then calculates the noise figure using the resulting values.

Data Consistency

If the data source is a MathWorks™ AMP file or an Agilent S2D file that contains both network parameter data and power data, the blockset checks the data for consistency and reconciles it as necessary.

The blockset compares the small-signal amplifier gain defined by the network parameters, S₂₁, and by the power data, P_out-P_in. The discrepancy between the two is computed in dBm using the following equation:

$$\begin{array}{cc}\Delta P=S_{21}(f_P)-P_{out}(f_P)+P_{in}(f_P)& (dBm)\end{array}$$

where f_P is the lowest frequency for which power data is specified.

If ΔP is more than 0.4 dB, a warning appears, and the blockset adds ΔP to the output power values at each specified input power value to resolve the discrepancy for simulation. The following graph shows this discrepancy.

Parameters to plot in X-Y pane

When you select Data source to Data file, you can plot the parameters listed in this table in X-Y plane by selecting the Y parameters1 and Y parameters2 on the Visualization tab.

S11	S12	S21	S22
GroupDelay	GammaIn	GammaOut	VSWRIn
VSWROut	OIP3	IIP3	NF
NFactor	NTemp	TF1	TF2
TF3	Gt	Ga	Gp
Gmag	Gmsg	GammaMS	GammaML
K	Delta	Mu	MuPrime
Fmin	GammaOPT	RN	Pout
Phase	AM/AM	AM/PM

When you select Data source to RFDATA object, you can plot the parameters listed in this table in X-Y plane by selecting the Y parameters1 and Y parameters2 on the Visualization tab.

S11	S12	S21	S22
GroupDelay	OIP3	NF	NFactor
NTemp	Fmin	GammaOPT	RN
Pout	Phase	AM/AM	AM/PM

Version History

Introduced before R2006a