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RF Budget Analyzer

Analyze gain, noise figure, IP2, and IP3 of cascaded RF elements and export to RF Blockset

Description

The RF Budget Analyzer app analyzes the gain, noise figure, and nonlinearity of proposed RF system architecture.

Using this app, you can:

  • Build a cascade of RF elements.

  • Calculate the per-stage and cascade output power, gain, noise figure, SNR, and IP3 of the system.

  • Compute nonlinear effects such as output power, IP2, NF, and SNR using harmonic balance analysis.

  • Plot rfbudget results across bandwidths and over stages.

  • Plot S-parameters of the RF System on a Smith chart and a polar plot.

  • Plot magnitude, phase and real, and imaginary parts of S-parameters of the RF System and over stages.

  • Export per-stage and cascade values to the MATLAB® workspace.

  • Export the system design to RF Blockset™ for simulation.

  • Export the system design to the RF Blockset Testbench as a device under test (DUT) subsystem and verify the results using simulation.

  • Visualize budget results and S-parameters over stages and frequencies.

  • Compare Friis and harmonic balance budget results.

Available Blocks

The app toolstrip contains these nonlinear elements that you can use to create an RF system:

  • Amplifier

  • Modulator

  • Demodulator

  • Generic

The app toolstrip contains these linear elements that you can use to create an RF system:

  • S-Parameters

  • Transmission Line

  • Filter

Available Templates

The app toolstrip contains these templates that you can use to design a transmitter or a receiver system:

  • Receiver

  • Transmitter

RF Budget Analyzer app

Open the RF Budget Analyzer App

  • MATLAB Toolstrip: On the Apps tab, under Signal Processing and Communications, click the app icon.

  • MATLAB command prompt: Enter rfBudgetAnalyzer.

Examples

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Design and analyze an RF transmitter using the RF Budget Analyzer app.

Enter rfBudgetAnalyzer to open the app.

Use the Transmitter template to create a basic transmitter.

The transmitter template is displayed as follows.

In System Parameters, specify the RF transmitter requirements:

  • Input Frequency815 MHz

  • Available Input Power0 dBm

  • Signal Bandwidth100 MHz

Click the IFAmplifier in the design canvas. Delete it using the Delete Element button on the toolstrip.

Add a Generic element in the place of the IFAmplifier using the toolstrip. In the Element Parameters pane, specify:

  • NameIFFilter

  • Available Power Gain -3.6 dB

  • Select Apply.

Click the Modulator element. In the Element Parameters pane, specify:

  • NameMixer

  • Available Power Gain-6.5 dB

  • OIP311.5 dBm

  • LO Frequency4.97 GHz

  • Converter TypeUp

  • Select Apply.

Delete the S-Parameters element named BandpassFilter. Add a Generic element. In the Element Parameters pane, specify:

  • NameRFFilter1

  • Available Power Gain-1.4 dB

  • Select Apply.

Select the PowerAmplifier element and in the Element Parameters pane, specify:

  • NamePowerAmplifier1

  • Available Power Gain20 dB

  • OIP343 dBm

  • Select Apply.

Add another Amplifier element using the toolstrip. In the Element Parameters pane, specify:

  • NamePowerAmplifier2

  • Available Power Gain20 dB

  • OIP343 dBm

  • Select Apply.

Add another Generic element. In the Element Parameters pane, specify:

  • NameRFFilter2

  • Available Power Gain-1.4 dB

  • Select Apply.

Save the system. The app saves the system in a MAT file.

Plot the output power of the transmitter using the 3D Plot button. Select 3D Plot and choose Output Power - Pout.

Design and analyze an RF receiver using the RF Budget Analyzer app.

Enter rfBudgetAnalyzer to open the app.

Use the Receiver template option to create a basic receiver.

The receiver template is displayed as follows:

In System Parameters, specify the RF receiver requirements:

  • Input Frequency5.745 MHz

  • Available Input Power-65 dBm

  • Signal Bandwidth100 MHz

Click RFFilter in the design canvas. This RFFilter is an S-parameters element. It accepts a Touchstone® file in the S2P file type. Update the Element parameters pane as follows:

  • Name: BandpassFilter

  • S2P file: Choose an S2P file by clicking the Browse button.

  • Select Apply.

Click the RFAmplifier element. In the Element Parameters pane, specify the element requirements:

  • NameLNA1

  • Available Power Gain12 dB

  • OIP320 dBm

  • Select Apply.

Add another Amplifier element using the toolstrip. In the Element Parameters pane, specify the element requirements:

  • NameLNA2

  • Available Power Gain12 dB

  • OIP320 dBm

  • Select Apply.

Add a Generic element. In the Element Parameters pane, specify the element requirements:

  • NameIRFilter

  • Available Power Gain-4.05 dB

  • Select Apply.

Click the Demodulator element. In the Element Parameters pane, specify the element requirements:

  • NameMixer

  • Available Power Gain-6.5 dB

  • OIP311.5 dBm

  • LO Frequency4.93 GHz

  • Converter TypeDown

  • Select Apply.

Delete the IFFilter, S-parameters element. Add a Generic element in its place. In the Element Parameters pane, specify the element requirements:

  • NameCSFilter

  • Available Power Gain-9.55 dB

  • Select Apply.

Click the IFAmplifier element. In the Element Parameters pane, specify the element requirements:

  • NamePowerAmp1

  • Available Power Gain16 dB

  • OIP326 dBm

  • Select Apply.

Add two more Amplifier elements. For each element, in the Element Parameters panes specify the element requirements:

  • Name PowerAmp2 | PowerAmp3

  • Available Power Gain16 dB | 20 dB

  • OIP326 dBm | 33 dBm

  • Select Apply.

Save the system. The app saves the system in a MAT file.

Plot the output OIP3 of the receiver using the 3D Plot button. Select the 3D Plot button and choose Output Third-Order Intercept Point - OIP3.

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 nport using passive.s2p.

n = nport('passive.s2p');

Create an RF element with a gain of 10 dB.

r = rfelement('Gain',10);

Calculate the rfbudget 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);

Run this command in the command window, to open the system in RF Budget Analyzer app.

show(b)

Set OIP2 value of Amplifier to 60 dBm using Elements Parameters pane and select Apply. In System Parameters section, set the Available Input Power to 50 dBm and run harmonic balance analysis using HB-Analyze button.

The results are displayed as shown below.

Select Auto-Analyze checkbox to automatically recompute the harmonic balance analysis calculations.

Set OIP2 value of RFelement as 50 dBm using Elements Parameters pane and select Apply.

Select Compare View checkbox in the Results pane to compare the calculated Friis and harmonic balance solver results. You can use Select Results drop-down from the Results pane to filter the results and to compare between Friis and harmonic balance solver.

Design an input matching network for a two-stage amplifier using the Transmission Line element in the RF Budget Analyzer app.

Enter rfBudgetAnalyzer to open the app.

In System Parameters, specify the requirements:

  • Input Frequency2.45 GHz

  • Available Input Power0 dBm

  • Signal Bandwidth2 GHz

Add two Transmission Line elements. In the Element Parameters pane, specify:

  • NameMicrostrip1 | Microstrip2

  • Type microstrip | microstrip

  • Width0.0034173 | 0.0034173 meters

  • Height0.001524 | 0.001524 meters

  • Thickness3.5e-06 | 3.5e-06 meters

  • EpsilonR3.48 | 3.48

  • LossTangent0.0037 | 0.0037 meters

  • SigmaCond Inf | Inf S/m

  • LineLength0.0089 | 0.0147 meters

  • StubModeShunt | NotAStub

  • TerminationOpen

  • Select Apply.

Add two S-Parameters elements. In the Element Parameters pane, specify:

  • Name Sparams1 | Sparams2

Load the Touchstone® file (f551432p.s2p) to the S-Parameters elements provided in this example and select Apply.

Plot the input reflection coefficient of the system using the 3D Plot button. Select the 3D Plot button, choose S-Parameters and select S11.

Design an RF system and plot S-parameters, output power, and transducer gain using RF Budget Analyzer app.

Enter rfBudgetAnalyzer to open the app.

In System Parameters, specify the requirements:

  • Input Frequency2.1 GHz

  • Available Input Power-30 dBm

  • Signal Bandwidth45 MHz

Add a S-Parameters element. In the Element Parameters, specify:

  • Name RFBandpassFilter

Load the Touchstone® file (RFBudget_RF.s2p) to the S-Parameters element provided in this example and select Apply.

Add an Amplifier element. In the Element Parameters, specify:

  • NameRFAmplifier

  • Available Power Gain11.53 dB

  • NF1.53 dB

  • OIP335 dBm

  • Select Apply.

Add the Demodulator element. In the Element Parameters, specify:

  • NameDemodulator

  • Available Power Gain-6 dB

  • NF — 4 dB

  • OIP350 dBm

  • LO Frequency2.03 GHz

  • Converter TypeDown

  • Select Apply.

Add another S-Parameters element. In the Element Parameters, specify:

  • Name IFBandpassFilter

Load the Touchstone file (RFBudget_IF.s2p) to the S-Parameters element provided in this example and select Apply.

Add another Amplifier element. In the Element Parameters, specify:

  • NameIFAmplifier

  • Available Power Gain30 dB

  • NF8 dB

  • OIP337 dBm

  • Select Apply.

Save the system. The app saves the system in a MAT file.

Select S-Parameters Plot button. This allows you to plot Smith® chart, polar plot, magnitude, phase and real, and imaginary parts of S-parameters of the RF System and over stages.

Set the Plot Bandwidth to 75 and Resolution to 250 under Plots section.

The S-parameters data is displayed as follows.

Select Phase (deg) from the drop-down menu of XY Plot in S-Parameters pane to plot the phase of the S21.

The phase plot is displayed as shown.

Plot the output power of the RF system using the 2D Plot button. Select 2D Plot button and choose Output Power - Pout.

2-D output power is displayed.

Plot the transducer gain of the RF system using the 2D Plot button. Select 2D Plot button and choose Transducer Gain - GainT.

Related Examples

Programmatic Use

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rfBudgetAnalyzer opens the RF Budget Analyzer app to analyze the per-stage and total gain, noise figure, and nonlinearity (IP3) of an RF system.

rfBudgetAnalyzer(rfsystem) opens an RF system saved using the RF Budget Analyzer app. rfsystem is a MAT file.

Tips

  • The RF Budget Analyzer app accepts 0 Hz as Input Frequency for a system. You can set the Input Frequency in the System Parameters section.

  • The RF Budget Analyzer app does not accept 0 Hz as LO Frequency. This is applicable to Modulator and Demodulator elements.

  • In the Filter Element pane, when you set the Filter Type to 'InverseChebyshev', you can only use the 'Transfer function' implementation.

  • The output frequencies are always positive.

References

[1] Pozar, David M. Microwave Engineering. 4th ed. Hoboken, NJ: Wiley, 2012.

Introduced in R2016a