RF Budget Analyzer

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

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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.

Note
SNR calculation of an RF chain in RF Budget Analyzer app uses 290K as a reference temperature.
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.

Note
If you use a stripline element in your system, then the app does not support exporting your system to RF Blockset.
Export the system design to the RF Blockset Testbench as a device under test (DUT) subsystem and verify the results using simulation.

Note
If you use an antenna element, the app does not support exporting to a testbench in the RF Blockset using the Measurement Testbench option.
Export the system design to rfsystem system object.
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
Filter
Transmission Line
Series RLC
Shunt RLC
Attenuator
Transmitter Antenna
Receiver Antenna
Transmit-Receive Antenna
LC Ladder
Phase Shift

Available Templates

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

Receiver
Transmitter

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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RF Transmitter System Analysis

Open Live Script

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 Frequency — 815 MHz
Available Input Power — 0 dBm
Signal Bandwidth — 100 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:

Name — IFFilter
Available Power Gain — -3.6 dB
Select Apply.

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

Name — Mixer
Available Power Gain — -6.5 dB
OIP3 — 11.5 dBm
LO Frequency — 4.97 GHz
Converter Type — Up
Select Apply.

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

Name — RFFilter1
Available Power Gain — -1.4 dB
Select Apply.

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

Name — PowerAmplifier1
Available Power Gain — 20 dB
OIP3 — 43 dBm
Select Apply.

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

Name — PowerAmplifier2
Available Power Gain — 20 dB
OIP3 — 43 dBm
Select Apply.

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

Name — RFFilter2
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.

Use Transmit Antenna in your RF Transmitter Design

This example uses:

Open Live Script

This example uses an RF transmitter design from the RF Transmitter System Analysis example.

Follow the RF Transmitter System Analysis example to design an RF transmitter. Select the antenna element from the Elements section and add the element at end of this RF transmitter. In the Element Parameters pane, select Antenna Designer from the Antenna Source drop-down list.

Click Create Antenna in the Element Parameters pane.

The Antenna Designer app opens. Click New to explore the antenna library. This example uses a dipoleFolded antenna element with a center frequency of 815 MHz. To do this, select Folded element from the Antenna Gallery, set Design Frequency to 815 MHz, and click Accept.

The updated antenna shows in the window.

Click Update Element to update the Antenna element in the RF Budget Analyzer app. Click OK in the Confirm Update dialog box.

The Antenna Designer app window closes and the Antenna element is updated in the RF Budget Analyzer app. The Results pane is automatically updated for Friis analysis with EIRP and Directivity of the Antenna element.

RF Receiver System Analysis

Open Live Script

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 Frequency — 5.745 MHz
Available Input Power — -65 dBm
Signal Bandwidth — 100 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:

Name — LNA1
Available Power Gain — 12 dB
OIP3 — 20 dBm
Select Apply.

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

Name — LNA2
Available Power Gain — 12 dB
OIP3 — 20 dBm
Select Apply.

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

Name — IRFilter
Available Power Gain — -4.05 dB
Select Apply.

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

Name — Mixer
Available Power Gain — -6.5 dB
OIP3 — 11.5 dBm
LO Frequency — 4.93 GHz
Converter Type — Down
Select Apply.

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

Name — CSFilter
Available Power Gain — -9.55 dB
Select Apply.

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

Name — PowerAmp1
Available Power Gain — 16 dB
OIP3 — 26 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 Gain — 16 dB | 20 dB
OIP3 — 26 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.

Compare Friis and Harmonic Balance Solver

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 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 Input Matching Network Using Transmission Line Element

Open Live Script

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 Frequency — 2.45 GHz
Available Input Power — 0 dBm
Signal Bandwidth — 2 GHz

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

Name — Microstrip1 | Microstrip2
Type — microstrip | microstrip
Width — 0.0034173 | 0.0034173 meters
Height — 0.001524 | 0.001524 meters
Thickness — 3.5e-06 | 3.5e-06 meters
EpsilonR — 3.48 | 3.48
LossTangent — 0.0037 | 0.0037 meters
SigmaCond — Inf | Inf S/m
LineLength — 0.0089 | 0.0147 meters
StubMode — Shunt | NotAStub
Termination — Open
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.

Plot S-Parameters, Output Power, and Transducer Gain of RF System

Open Live Script

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 Frequency — 2.1 GHz
Available Input Power — -30 dBm
Signal Bandwidth — 45 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:

Name — RFAmplifier
Available Power Gain — 11.53 dB
NF — 1.53 dB
OIP3 — 35 dBm
Select Apply.

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

Name — Demodulator
Available Power Gain — -6 dB
NF — 4 dB
OIP3 — 50 dBm
LO Frequency — 2.03 GHz
Converter Type — Down
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:

Name — IFAmplifier
Available Power Gain — 30 dB
NF — 8 dB
OIP3 — 37 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.

Perform HB Analysis on RF Receiver Designed Using `rfsystem`

This example uses:

Open Script

Design an RF receiver using the rfsystem system object. View the object in the the RF Budget Analyzer app to perform harmonic balance (HB) analysis.

Create fifth- and seventh-order bandpass RF filters.

f1 = rffilter('ResponseType','Bandpass','FilterOrder',5, ...
        'PassbandFrequency',[4.85 5.15]*1e9);
f2 = rffilter('ResponseType','Bandpass','FilterOrder',7, ...
        'PassbandFrequency',[10 130]*1e6);

Create two amplifier objects with 3 dB and 5 dB gain, respectively.

a1 = amplifier('Gain',3,'NF',1.53,'OIP3',35);
a2 = amplifier('Gain',5,'NF',8,'OIP3',37);

Create a modulator with a local frequency of 4.93 GHz.

d = modulator('Gain',0,'NF',4,'OIP3',50,'LO',4.93e9, ...
        'ConverterType','Down');

Design an RF receiver with the budget elements at an input frequency of 5 GHz, an available input power of – 30 dBm, and a bandwidth of 10 MHz.

rfb = rfbudget([f1 a1 d f2 a2],5e9,-30,10e6);

Create an RF system for the RF receiver using the rfbudget object.

rfs = rfsystem(rfb);

Open an RF Blockset model of the designed RF system using the open_system object function.

open_system(rfs)

Type rfBudgetAnalyzer(rfs) command at the MATLAB® command line to open this RF system in the RF Budget Analyzer app.

To conduct HB analysis in the app, click the HB-Analyze button.

Related Examples

Programmatic Use

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