dB Gain

Apply decibel gain

Libraries:
DSP System Toolbox / Math Functions / Math Operations

Description

The dB Gain block multiplies the input by the decibel values specified in the Gain parameter. You can specify the input to be a power signal or a voltage signal.

For more information on how the block applies the decibel gain, see Algorithms.

Ports

Input

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Input — Input signal
scalar | vector | matrix

Specify the input signal as a scalar, vector, or a matrix of size M-by-N.

Output

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Output — Output after applying the decibel gain
scalar | vector | matrix

Output after applying the decibel gain, returned as a scalar, vector, or a matrix of the same size, data type, and complexity as the input signal.

For more information on how the block applies the decibel gain, see Algorithms.

Parameters

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Note

This block does not support tunability in generated code.

Gain, dB — Gain
`-40` (default) | scalar | matrix

Specify the dB gain to apply to the input as a scalar or a real matrix of the same size as the input matrix.

Tunable: Yes

Input signal — Input signal
`Amplitude` (default) | `Power`

Specify the type of input signal as one of these:

Power –– The block treats the signal as the power signal.
Amplitude –– The block treats the signal as the voltage signal.

Tunable: Yes

Block Characteristics

Data Types	`double` \| `fixed point` \| `integer` \| `single`
Direct Feedthrough	`no`
Multidimensional Signals	`no`
Variable-Size Signals	`no`
Zero-Crossing Detection	`no`

More About

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Fixed-Point Data Types

The following diagram shows the data types used within the dB Gain subsystem block for fixed-point signals.

The settings for the fixed-point parameters of the Gain block in the diagram above are as follows:

Integer rounding mode –– Floor
Saturate on integer overflow — unselected
Parameter data type mode — Inherit via internal rule
Output data type mode — Inherit via internal rule

See the Gain (Simulink) reference page for more information.

Algorithms

For an M-by-N input matrix u with elements u_ij, the Gain parameter can be a real M-by-N matrix with elements g_ij to be multiplied element-wise with the input, or a real scalar.

$y_{i j} = u_{i j} 10^{(g_{i j} / k)}$

The value of k is 10 for power signals (select Power as the Input signal parameter) and 20 for voltage signals (select Amplitude as the Input signal parameter).

The value of the equivalent linear gain

$g_{i j}^{l i n} = 10^{(g_{i j} / k)}$

is displayed in the block icon below the dB gain value.

Extended Capabilities

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

This block does not support tunability in generated code.

Version History

Introduced before R2006a

dB Gain

Description

Ports

Input

Input — Input signal
scalar | vector | matrix

Output

Output — Output after applying the decibel gain
scalar | vector | matrix

Parameters

Gain, dB — Gain
`-40` (default) | scalar | matrix

Input signal — Input signal
`Amplitude` (default) | `Power`

Block Characteristics

More About

Fixed-Point Data Types

Algorithms

Extended Capabilities

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

Version History

See Also

Functions

Blocks

dB Gain

Description

Ports

Input

Input — Input signal scalar | vector | matrix

Output

Output — Output after applying the decibel gain scalar | vector | matrix

Parameters

Gain, dB — Gain -40 (default) | scalar | matrix

Input signal — Input signal Amplitude (default) | Power

Block Characteristics

More About

Fixed-Point Data Types

Algorithms

Extended Capabilities

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

Version History

See Also

Functions

Blocks

Input — Input signal
scalar | vector | matrix

Output — Output after applying the decibel gain
scalar | vector | matrix

Gain, dB — Gain
`-40` (default) | scalar | matrix

Input signal — Input signal
`Amplitude` (default) | `Power`

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