RF Budget Analyzer

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

Enter rfBudgetAnalyzer to open the app.

Select New and then select select Transmitter to use the transmitter template to create a basic transmitter.

The transmitter template is displayed as follows.

In System Parameters, specify the RF transmitter requirements:

Click the IFAmplifier in the design canvas and delete the element 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:

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

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

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

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

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

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.

Select the PowerAmplifer1 element and from the Element Parameters pane, and then click the Plot Power Characteristics button to plot amplifier power characteristics of the PowerAmplifer1 element. Alternatively, to plot the amplifier power characteristics of the PowerAmplifer1 element, select the PowerAmplifer1 element and using the 2-D Plot button, choose Plot Power Characteristics.(Since 2023a)

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.

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

Enter rfBudgetAnalyzer to open the app.

Click the New button and select Receiver to 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:

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:

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

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

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

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

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

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

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

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 from the Harmonic Balance section 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:

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

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

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:

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

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:

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

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

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:

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.

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.

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

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

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

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

rfs = rfsystem(rfb);

open_system(rfs)