Main Content

rfantenna

Create antenna element modeled as transmitter, receiver, or transmit-receive

Since R2021a

expand all in page

    Description

    Use the rfantenna object to create an antenna element that you can model as a transmitter, receiver, or transmit-receive configuration. If you design an RF system using an rfbudget object or the RF Budget Analyzer app you can model an RF antenna with the rfantenna object and add it to the RF system. You can export the element to RF Blockset™ or to an rfsystem System object™ for circuit envelope analysis.

    Creation

    Syntax

    ant = rfantenna
    ant = rfantenna(Name=Value)

    Description

    ant = rfantenna creates a default RF antenna object with a gain of 1 dBi.

    ant = rfantenna(Name=Value) sets the Properties of an rfantenna object using one or more name-value arguments. For example, ant = rfantenna(Gain=10) creates an RF antenna object with a 10 dBi gain. Properties you do not specify retain their default values.

    example

    Properties

    expand all

    Name of the RF antenna element, specified as a string scalar or a character vector.

    Example: rfantenna(Name='Antenna_20dB')

    Antenna gain, specified as either: nonnegative scalar (default value is 0) or two-element vector (default value is [0 0]) in dBi. Specify Gain as a two-element vector when you set the Type property to TransmitReceive. To control the effective isotropically radiated power (EIRP), vary the gain of the antenna element.

    Example: rfantenna(Gain=20)

    Input impedance of the RF antenna element, specified as either: positive scalar (default value is 50) or two-element vector (default value is [50 50]) in ohms. Specify Z as a two-element vector when you set the Type property to TransmitReceive.

    Example: rfantenna(Z=20)

    Type of the antenna element, specified as a 'Transmitter', 'Receiver', or 'TransmitReceive'. When you set Type to 'TransmitReceive', the transmitter and receiver antennas operate simultaneously.

    Example: rfantenna(Type='Receiver')

    EIRP value of the transmitting antenna that the receiver is tuned to, specified as a numerical scalar in dBm. You must set this property when you are designing a receiver antenna element.

    Example: rfantenna(TxEIRP=24)

    Loss encountered by a signal before reaching the receiver, specified as a nonnegative scalar in dB.

    Example: rfantenna(PathLoss=2)

    This property is read-only.

    Number of input and output ports in RF antenna element, specified as a positive scalar.

    This property is read-only.

    Terminals of RF antenna, specified as a cell array.

    Object Functions

    sparametersCalculate S-parameters for RF data, network, circuit, and matching network objects

    Examples

    collapse all

    Open Live Script

    Create an amplifier with the gain of 4 dB.

    a = amplifier(Gain=4);

    Create a modulator with OIP3 of 13 dBm.

    m = modulator(OIP3=13);

    Create an n-port element using passive.s2p.

    n = nport('passive.s2p');

    Create an RF antenna with the gain of 10 dB.

    ant = rfantenna(Gain=10);

    Calculate the RF budget of a series of RF elements at the input frequency of 2.1 GHz, available input power of –30 dBm, and bandwidth of 10 MHz. EIRP is computed under Analyzed Results of the rfbudget object.

    b = rfbudget([a m n ant],2.1e9,-30,10e6)
    b = 
  rfbudget with properties:

               Elements: [1x4 rf.internal.rfbudget.Element]
         InputFrequency: 2.1 GHz
    AvailableInputPower: -30 dBm
        SignalBandwidth:  10 MHz
                 Solver: Friis      
             AutoUpdate: true

   Analysis Results
        OutputFrequency: (GHz) [  2.1    3.1      3.1      3.1]
            OutputPower: (dBm) [  -26    -26    -30.6    -30.6]
         TransducerGain: (dB)  [    4      4  -0.5995  -0.5995]
                     NF: (dB)  [    0      0    1.224    1.224]
                   IIP2: (dBm) []                              
                   OIP2: (dBm) []                              
                   IIP3: (dBm) [  Inf      9        9        9]
                   OIP3: (dBm) [  Inf     13      8.4      8.4]
                    SNR: (dB)  [73.98  73.98    72.75    72.75]
                   EIRP: (dBm) [-20.6]                         
            Directivity: (dBi) [   10]
    Open Live Script

    Design an RF receiver antenna element given a transmitting antenna with an EIRP value of –35 dBm and a pathloss of 2 dB.

    antR = rfantenna(Type ='Receiver',TxEIRP =-35,PathLoss=2);

    Create an amplifier with a gain of 4 dB.

    a = amplifier(Gain=4);

    Create a modulator with an OIP3 value of 13 dBm.

    m = modulator(OIP3=13);

    Create an n-port element using passive.s2p.

    n = nport('passive.s2p');

    Calculate the RF budget of a series of RF elements by tying this command at the command line with an input frequency of 2.1 GHz, an available input power of –30 dBm, and a bandwidth of 10 MHz. 

    b = rfbudget([antR a m n],2.1e9,-30,10e6);

    rfant.png

    Use the show command at the command line to visualize the RF budget chain in the RF Budget Analyzer app. To do further analysis on this chain using this app see RF Budget Analyzer. 

    show(b)

    rfant.png

    Open Live Script

    Create an RF antenna element in a transmit-receive configuration. Set the gain and the impedance of the transmitter to 5 dB and 45 ohms, respectively, and the gain and impedance of the receiver antenna to 6 dB and 55 ohms, respectively.

    ant = rfantenna('Type','TransmitReceive','Gain',[5 6],'Z',[45 55])
    ant = 
  rfantenna: Antenna element

        Name: 'Antenna'
        Type: 'TransmitReceive'
        Gain: [5 6]
           Z: [45 55]
    PathLoss: 0

    Calculate the S-parameters of the RF antenna element in the transmit-receive configuration at 1 GHz.

    sparam = sparameters(ant,1e9)
    sparam = 
  sparameters with properties:

      Impedance: 50
       NumPorts: 1
     Parameters: -0.0025
    Frequencies: 1.0000e+09

    Version History

    Introduced in R2021a

    expand all

    See Also

    Topics