friisrxpow

R2026b

Received power estimation using Friis equation

Since R2026b

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    Syntax

    Pr = friisrxpow(lambda,R,Pt)
    Pr = friisrxpow(lambda,R,Pt,name=value)

    Description

    Pr = friisrxpow(lambda,R,Pt) returns the received power Pr at a receiver located a distance R away from a transmitter. Pt is the transmitted power and lambda is the wavelength.

    example

    Pr = friisrxpow(lambda,R,Pt,name=value) specifies additional options using one or more name-value arguments in addition to the input arguments of the previous syntax.

    Examples

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    Open Live Script

    Use the Friis equation to compute the received power at a receiver located 10 km away from a transmitter. The transmitted power is 0.5 W and the frequency is 437 MHz. The path loss exponent is 2.

    Pt = 0.5;
f = 437*1e6;
lambda = physconst("LightSpeed")/f;
R = 10e3;
Pr = friisrxpow(lambda,R,Pt,"PathLossExponent",2)
    Pr = 
1.4901e-11

    Input Arguments

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    Signal wavelength, specified as a positive scalar or a positive-valued 1-by-N row vector. If more than one input is a vector, the size N must be the same for all inputs. Units are in meters.

    Example: 3.0e8

    Data Types: double

    Distance to the radar receiver from the transmitter, specified as a positive scalar or a positive-valued 1-by-N row vector. If more than one input is a vector, the size N must be the same for all inputs. Units are in meters.

    Example: 1500

    Data Types: double

    Transmitted power, specified as a positive scalar or a positive-valued 1-by-N row vector. Units are in Watts.

    Pt and R can be scalars or row vectors. If both inputs are vectors, the size N must be the same for all inputs.

    Example: 1000.0

    Data Types: double

    Name-Value Arguments

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    Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

    Example: PathLossExponent=2.5

    Receive and transmit antenna gains, specified as a real-valued row vector or real-valued 2-column matrix. Units are in dBi.

    • When Gain is a row vector, the transmit and receive antennas have the same gain. The number of columns must either equal 1 or be equal to the number of columns in Pt or R if any one of them is a vector.

    • When Gain is a 2-row matrix, the first row specifies the gain of the transmit antenna and the second row specifies the gain of the receive antenna.

    Example: Gain=[10,20]

    Data Types: double

    Additional system loss, specified as a row vector. System losses include transmitter, receiver, or atmospheric losses. The number of columns in the Loss property must either be 1 or match the number of columns in the Pt and R input arguments or the Gain if any one of them is a vector. Units are in dB.

    Example: Loss=[5 10]

    Data Types: double

    Path loss exponent, specified as a real-valued row vector. The number of columns must either equal 1 or match the number of columns in Pt, R, or Gain. Units are dimensionless.

    Example: PathLossExponent = 2.1

    Data Types: double

    Output Arguments

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    Received power, returned as a positive-valued row vector. The received power is computed from the corresponding lambda, Pt, and R pairs. Units are in Watts.

    Data Types: double

    Extended Capabilities

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

    Version History

    Introduced in R2026b

    See Also

    External Websites