rfelement

Generic RF element object

Description

Use the rfelement object to create a generic RF element. An RF element is a 2–port RF circuit object. You can use this element in the rfbudget object and the circuit object.

Creation

Syntax

rfel = rfelement

rfel = rfelement(Name=Value)

Description

rfel = rfelement creates an RF element object with default property values.

rfel = rfelement(Name=Value) sets properties using one or more name-value pairs. You can specify multiple name-value arguments.

Properties

Name — Name given to identify RF element

"RFelement" (default) | character vector

Name given to identify rf element, specified as a character vector. All names must be valid MATLAB^® variable names.

Example: Name="rfel"

Example: rfel.Name = "rfel"

FileName — Name of two-port Touchstone file

string scalar | character vector

Name of the two-port Touchstone file that contains modulator data, specified as a string scalar or character vector.

Example: FileName='default.s2p'

SystemData — RF element system data

rfSystemParameter object

Since R2026a

RF element system data, specified as an rfSystemParameters object.

Example: SystemData=rfSystemParameters('RF_model.csv')

Gain — Available power gain

0 (default) | scalar

Available power gain, specified as a scalar in dB.

Example: Gain=10

Example: rfel.Gain = 10

NF — Noise figure

0 (default) | real finite nonnegative scalar

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

Example: NF=-10

Example: rfel.NF = -10

OIP2 — Second -order output-referred intercept point

Inf (default) | real scalar

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

Example: OIP2=8

Example: amplifier.OIP2 = 8

OIP3 — Third -order output-referred intercept point

Inf (default) | real scalar

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

Example: OIP3=10

Example: amplifier.OIP3 = 10

OP1dB — Output 1 dB compression point

inf (default) | real positive number

Since R2026a

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

Example: OP1dB=20

OPsat — Output saturation point

inf (default) | real positive number

Since R2026a

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

Example: OPsat=20

Zin — Input impedance

50 (default) | positive real part finite scalar

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

Example: rfel.Zin = 40

Zout — Output impedance

50 (default) | positive real part finite scalar

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

Example: Zout=40

Example: rfel.Zout = 40

NumPorts — Number of ports

2 (default) | scalar integer

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

'Terminals' — Names of port terminals

{'p1+' 'p2+' 'p1-' 'p2-'} (default) | cell vector

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

Object Functions

clone

Create copy of existing circuit element or circuit object

Examples

RF Element

Create an rfelement object with a gain of 10 dB, noise figure of 3 dB, and OIP3 (output third-order intercept) of 2 dBm.

r = rfelement(Gain=10,NF=3,OIP3=2)

r = 
  rfelement: RF element

     Name: 'RFelement'
     Gain: 10
      Zin: 50
     Zout: 50
       NF: 3
     IIP2: Inf
     OIP2: Inf
     IIP3: -8
     OIP3: 2
    IP1dB: Inf
    OP1dB: Inf
    IPsat: Inf
    OPsat: Inf

RF Element Circuit

Create an rf element with a gain of 4 dB. Create another rf element with an output third-order intercept(OIP3) of 13 dBm.

rfel1 = rfelement(Gain=4);
rfel2 = rfelement(OIP3=13);

Build a 2-port circuit using the above defined rf elements.

c = circuit([rfel1 rfel2])

c = 
  circuit: Circuit element

    ElementNames: {'RFelement'  'RFelement_1'}
        Elements: [1×2 rfelement]
           Nodes: [0 1 2 3]
            Name: 'unnamed'

RF Budget Analysis of Series of RF Elements

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  0.1391]
                   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)

Version History

Introduced in R2017a

R2026a: Model RF generic element using OP1dB and OPsat

You can now specify OP1dB and OPsat values to model an rfelement object.

R2026a: Model RF element using RF system data

Use the SystemData property to model an rfelement object.

R2023b: Recommended over rfdata.ip3

rfelement is recommended over rfdata.ip3 because it enables you to:

• Create a generic RF element with third-order intercept points.

• Build a circuit object with a generic RF element.

• Model an amplifier in an RF chain created using an rfbudget object or the RF Budget Analyzer app, and then export this element to RF Blockset™ or to rfsystem System object™ for circuit envelope analysis.