Amplifier

Complex baseband model of amplifier with noise and nonlinearities

Since R2020a

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Libraries:
RF Blockset / Idealized Baseband

Description

The Amplifier block generates a complex baseband model of an amplifier with thermal noise. This block provides four nonlinearity models and three options to specify noise representation.

Examples

Idealized Baseband Amplifier with Nonlinearity and Noise

The example shows how to use the idealized baseband library Amplifier block to amplify a signal with nonlinearity and noise. The Amplifier uses the Cubic Polynomial model with a Linear power gain of 10 dB, an Input IP3 nonlinearity of 30 dBm, and a Noise figure of 3 dB.

Open Script

Ports

Input

Port_1 — Input baseband signal

real scalar | real column | complex scalar | complex column

Input baseband signal, specified as a real scalar, real column, complex scalar, or complex column.

Data Types: double | single

Output

Port_1 — Output baseband signal

real scalar | real column | complex scalar | complex column

Output baseband signal, specified as a real scalar, real column, complex scalar, or complex column. The output port mimics the properties of the input port. For example, if the input baseband signal is specified as a real scalar with a data type double, then the output baseband signal is also specified as a real signal with the data type double.

Data Types: double | single

Parameters

Main Tab

Model — Amplifier nonlinearity model

Cubic polynomial (default) | AM/AM - AM/PM | Modified Rapp | Saleh

Specify the amplifier nonlinearity model as one of the following:

• Cubic polynomial

• AM/AM - AM/PM

• Modified Rapp

• Saleh

For more information, see Nonlinearity Models in Idealized Amplifier Block.

Linear power gain (dB) — Linear gain of amplifier

0 (default) | real scalar

Linear gain, specified as a scalar in dB.

Type of Non-Linearity — Third - order nonlinearity type

IIP3 (default) | OIP3 | IP1dB | OP1dB | IPsat | OPsat

Third order nonlinearity type, specified as IIP3, OIP3, IP1dB, OP1dB, IPsat, or OPsat.

IIP3 (dBm) — Input third-order intercept point

Inf (default) | real positive number

Input third-order intercept point, specified as a real positive number in dBm.

Dependencies

To enable this parameter, set Model to Cubic polynomial and Type of Non-Linearity to IIP3.

OIP3 (dBm) — Output third-order intercept point

Inf (default) | real positive number

Output third-order intercept point, specified as a real positive number in dBm.

Dependencies

To enable this parameter, set Model to Cubic polynomial and Type of Non-Linearity to OIP3.

IP1dB (dBm) — Input 1 dB compression point

Inf (default) | real positive number

Input 1 dB compression point, specified as a real positive number in dBm.

Dependencies

To enable this parameter, set Model to Cubic polynomial and Type of Non-Linearity to IP1dB.

OP1dB (dBm) — Output 1 dB compression point

Inf (default) | real positive number

Output 1 dB compression point, specified as a real positive number in dBm.

Dependencies

To enable this parameter, set Model to Cubic polynomial and Type of Non-Linearity to OP1dB.

IPsat (dBm) — Input saturation point

Inf (default) | real positive number

Input saturation point, specified as a real positive number in dBm.

Dependencies

To enable this parameter, set Model to Cubic polynomial and Type of Non-Linearity to IPsat.

OPsat (dBm) — Output saturation point

Inf (default) | real positive number

Output saturation point, specified as a positive real number in dBm.

Dependencies

To enable this parameter, set Model to Cubic polynomial and Type of Non-Linearity to OPsat.

Reference load (ohm) — Reference load

1 (default) | positive scalar

Reference load value in ohms, specified as a positive scalar. This value is used to convert between the voltage levels and the signal and noise power levels.

Tunable: Yes

Simulate using — Specify type of simulation to run

Code generation (default) | Interpreted execution

• Code generation – Simulate model using generated C code. The first time you run a simulation, Simulink^® generates C code for the block. The C code is reused for subsequent simulations, as long as the model does not change. This option requires additional startup time, but the speed of the subsequent simulations is faster than Interpreted execution.

• Interpreted execution – Simulate model using the MATLAB^® interpreter. This option shortens startup time speed, but the speed of the subsequent simulations is slower than Code generation. In this mode, you can debug the source code of the block.

Plot power characteristics — Plot power characteristics

button (default)

This button plots the power characteristics based on the parameters specified on the Main tab.

For more information, see Plot Power Characteristics.

Lookup table (Pin(dBm), Pout(dBm), deg) — Lookup table

[ -25, 5, -1; -10, 20, -2; 0, 27, 5; 5, 28, 12 ] (default) | M-by-3 real matrix

Table lookup entries specified as a real M-by-3 matrix. This table expresses the model output power dBm level in matrix column 2 and the model phase change in degrees in matrix column 3 as related to the absolute value of the input signal power of matrix column 1 for the AM/AM - AM/PM model. The column 1 input power must increase monotonically.

Dependencies

To enable this parameter, set Model to AM/AM - AM/PM.

Output saturation level (V) — Output saturation level

1 (default) | real positive number

Voltage output saturation level, specified as a real positive number in dBm.

Dependencies

To enable this parameter, set Model to Modified Rapp.

Magnitude smoothness factor — Magnitude smoothness factor

2 (default) | real positive number

Magnitude smoothness factor for the Modified Rapp amplifier model AM/AM calculations, specified as a positive real number.

Dependencies

To enable this parameter, set Model to Modified Rapp.

Phase gain (rad) — Phase gain

-0.45 (default) | real scalar

Phase gain for the Modified Rapp amplifier model AM/PM calculations, specified as a real scalar in radians.

Dependencies

To enable this parameter, set Model to Modified Rapp.

Phase saturation — Phase saturation

0.88 (default) | real positive number

Phase saturation for the Modified Rapp amplifier model AM/PM calculations, specified as a positive real number.

Dependencies

To enable this parameter, set Model to Modified Rapp.

Phase smoothness factor — Phase smoothness factor

3.43 (default) | real positive number

Phase smoothness factor for the Modified Rapp amplifier model AM/PM calculations, specified as a positive real number.

Dependencies

To enable this parameter, set Model to Modified Rapp.

Input scaling (dB) — Scaling factor for input signal level

0 (default) | nonnegative real number

Scaling factor for input signal level for the Saleh amplifier model, specified as a nonnegative real number in dB.

Dependencies

To enable this parameter, set Model to Saleh.

AM / AM parameters [alpha beta] — AM/AM conversion parameters

[ 2.1587, 1.1517 ] (default) | two-element vector

AM/AM two-tuple conversion parameters for Saleh amplifier model, specified as a two-element vector of nonnegative real numbers.

Dependencies

To enable this parameter, set Model to Saleh.

AM / PM parameters [alpha beta] — AM/PM conversion parameters

[ 4.0033, 9.1040 ] (default) | two-element vector

AM/PM two-tuple conversion parameters for Saleh amplifier model, specified as a two-element vector of nonnegative real numbers.

Dependencies

To enable this parameter, set Model to Saleh.

Output scaling (dB) — Scaling factor for output signal level

0 (default) | nonnegative real number

Scaling factor for output signal level for Saleh amplifier model, specified as nonnegative real number in dB.

Dependencies

To enable this parameter, set Model to Saleh.

Noise Tab

Include Noise — Add noise to system

off (default) | on

Select this parameter to add system noise to the input signal. Once you select this parameter, the parameters associated with the Noise tab are displayed.

Specify noise type — Noise representation

Noise temperature (default) | Noise figure | Noise factor

Noise descriptive type, specified as Noise temperature, Noise figure, or Noise factor.

For more information, see Thermal Noise Simulations in Idealized Amplifier Block.

Dependencies

To enable this parameter, select Include Noise.

Noise temperature (K) — Noise temperature to model noises in amplifier

290 (default) | nonnegative real number

Noise temperature to model noise in the amplifier, specified as a nonnegative real number in degrees (K).

Dependencies

To enable this parameter, select Include Noise and set Specify noise type to Noise temperature.

Noise figure (dB) — Noise figure to model noise in amplifier

10 * log10( 2 ) (default) | nonnegative real number

Noise figure to model noise in the amplifier, specified as a nonnegative real number in dB.

Dependencies

To enable this parameter, select Include Noise and set Specify noise type to Noise figure.

Noise factor — Noise factor to model noise in amplifier

2 (default) | positive integer scalar greater than or equal to 1

Noise factor to model noise in the amplifier, specified as a positive integer scalar greater than or equal to 1.

Dependencies

To enable this parameter, select Include Noise and set Specify noise type to Noise factor.

Seed source — Source of initial seed

Auto (default) | User specified

Source of initial seed used to prepare the Gaussian random number noise generator, specified as one of the following:

• Auto - When Seed source is set to Auto, seeds for each amplifier instance are generated using a random number generator. The reset method of the instance has no effect.

• User specified - When Seed source is set to User specified, the value provided in the Seed is used to initialize the random number generator and the reset method resets the random number generator using the Seed property value.

Seed — Seed for random number generator

67987 (default) | nonnegative integer

Seed for the random number generator, specified as a nonnegative integer less than 2³². Use this value to initialize the random number generator.

Dependencies

To enable this parameter, click Include Noise check box and choose User specified in the Seed source parameter.

References

[1] Razavi, Behzad. “Basic Concepts “ in RF Microelectronics, 2nd edition, Prentice Hall, 2012.

[2] Rapp, C., “Effects of HPA-Nonlinearity on a 4-DPSK/OFDM-Signal for a Digital Sound Broadcasting System.” Proceedings of the Second European Conference on Satellite Communications, Liege, Belgium, Oct. 22-24, 1991, pp. 179-184.

[3] Saleh, A.A.M., “Frequency-independent and frequency-dependent nonlinear models of TWT amplifiers.” IEEE Trans. Communications, vol. COM-29, pp.1715-1720, November 1981.

[4] IEEE 802.11-09/0296r16. “TGad Evaluation Methodology.“ Institute of Electrical and Electronics Engineers.https://www.ieee.org/

[5] Kundert, Ken.“ Accurate and Rapid Measurement of IP₂ and IP₃,“ The Designer Guide Community, May 22, 2002.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2020a

R2022b: Reference load parameter added to the block

You can now specify load resistance in ohms using the Reference load parameter.