modulator

Modulator object

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Description

Use the modulator object to create a modulator element. A modulator is a 2-port RF circuit object. You can use this element in the rfbudget object and the circuit object.

Creation

Syntax

mod = modulator
mod = modulator(Name=Value)

Description

mod = modulator creates a modulator object, mod, with default property values.

example

mod = modulator(Name=Value) creates a modulator object with additional properties specified by one or more name-value pair arguments. Properties not specified retain their default values.

example

Properties

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Name of modulator, specified as the comma-separated pair consisting of 'Name' and a character vector. All names must be valid MATLAB® variable names.

Example: Name='mod'

Since R2024b

Conversion type, specified as either:

  • 'mod' — Modulator

  • 'demod' — Demodulator

Example: Model='demod'

Available power gain, specified as a nonnegative scalar in dB.

Example: Gain=10

Noise figure, specified as a real finite nonnegative scalar in dB.

Example: NF=10

Second-order output-referred intercept point, specified as a real scalar in dBm.

Example: OIP2=8

Third-order output-referred intercept point, specified as a real scalar in dBm.

Example: OIP3=10

Local oscillator frequency, specified as a real finite positive scalar in Hz.

Example: LO=2e9

Ideal image reject filtering at the input of the modulator, specified as a numeric or logical 1 (true) or 0 (false). Setting this property to false or 0 might affect harmonic balance results.

Example: ImageReject=1

Example: ImageReject=true

Ideal channel select filtering at the output of the modulator, specified as a numeric or logical 1 (true) or 0 (false). Setting this property to false or 0 might affect harmonic balance results.

Example: ChannelSelect=1

Example: ChannelSelect=false

Input impedance, specified as a positive real part finite scalar in ohms. You can also use a complex value with a positive real part.

Example: Zin=40

Output impedance, specified as a scalar in ohms. You can also use a complex value with a positive real part.

Example: Zout=40

Number of ports, specified as a scalar integer. This property is read-only.

Names of port terminals, specified as a cell vector. This property is read-only.

Object Functions

cloneCreate copy of existing circuit element or circuit object

Examples

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Open Live Script

Create a downconverter modulator with a local oscillator (LO) frequency of 100 MHz.

m = modulator(Model='demod',LO=100e6)
m = 
  modulator: Modulator element

             Name: 'Modulator'
            Model: 'demod'
             Gain: 0
               NF: 0
             OIP2: Inf
             OIP3: Inf
              Zin: 50
             Zout: 50
               LO: 100000000
      ImageReject: 1
    ChannelSelect: 1
Open Live Script

Create a modulator object with a gain of 4 dB and local oscillator (LO) frequency of 2 GHz. Create another modulator object has an output third-order intercept (OIP3) of 13 dBm.

mod1 = modulator(Gain=4,LO=2e9);
mod2 = modulator(OIP3=13);

Build a two-port circuit using the modulators.

c = circuit([mod1 mod2])
c = 
  circuit: Circuit element

    ElementNames: {'Modulator'  'Modulator_1'}
        Elements: [1×2 modulator]
           Nodes: [0 1 2 3]
            Name: 'unnamed'
Open Live Script

Create an amplifier with a gain of 4 dB.

a = amplifier(Gain=4);

Create a modulator with an OIP3 of 13 dBm.

m = modulator(OIP3=13);

Create an N-port element using passive.s2p.

n = nport('passive.s2p');

Create an RF element with a gain of 10 dB.

r = rfelement(Gain=10);

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

b = rfbudget([a m r n],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    -16   -20.6]
         TransducerGain: (dB)  [    4      4     14     9.4]
                     NF: (dB)  [    0      0      0  0.1392]
                   IIP2: (dBm) []                           
                   OIP2: (dBm) []                           
                   IIP3: (dBm) [  Inf      9      9       9]
                   OIP3: (dBm) [  Inf     13     23    18.4]
                    SNR: (dB)  [73.98  73.98  73.98   73.84]

Type the show command at the command window to display the analysis in the RF Budget Analyzer app.

show(b)

amp_rf_app.png

Version History

Introduced in R2017a

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See Also

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