rfplot

Plot mixer spurs and spur-free zones of IMT mixer

Since R2022a

Syntax

rfplot(imt,frequency)

rfplot(ax,imt,frequency)

rfplot(___,Name=Value)

Description

rfplot(imt,frequency) plots the mixer spurs response of the mixerIMT object imt at the frequency specified in frequency. The function plots the mixer spurs on the current axes, with the frequency in Hz on the X-axis and the input power in dBm on the Y-axis.

rfplot(ax,imt,frequency) plots the mixer spurs on the axes specified in ax instead of the current axes. Return the current axes using the gca function.

rfplot(___,Name=Value) plots the spur and the spur-free zones of the mixerIMT object using additional options. Specify the name-value argument after any of the input argument combinations in the previous syntaxes. (since R2024a)

Examples

Plot Mixer Spur of IMT mixer

Create an IMT mixer with the LO frequency of 5995 MHz and with the IMT spurs.

imt = mixerIMT(LO=5995e6,IMT=...
     [99 17 13.6 42.9; 40 0 47.7 54.3; 50.4 58.5 61.3 72.2; 75 67.4 75 99]);

Plot the mixer spur at an input signal frequency of 1005 MHz.

rfplot(imt,1005e6)

Plot IMT Spurs in Tabs

Create an IMT mixer with 4-by-4 IMT spur data.

imt = mixerIMT(LO=5995e6,IMT=...
     [99 17 11.6 42.9; 40 0 44.7 54.3; 51.4 58.5 61.3 72.2; 75 67.4 73 99]);

Create an IMT mixer with 3-by-3 IMT spur data.

imt2 = mixerIMT(LO=5995e6,IMT=...
     [99 99 80; 99 0 99; 99 80 99]);

Type these commands at the command line to create a rfplot figure with two tabs. Add axes to each tab by specifying the parent container for each axis. Plot the IMT mixer with the 4-by-4 IMT spur data in the first tab and the IMT mixer with the 3-by-3 IMT spur data in the second tab.

figure
tab1 = uitab('Title','4-by-4 IMT spur data');
ax3 = axes(tab1);
rfplot(ax3,imt,1005e6)

tab2 = uitab('Title','3-by-3 IMT spur data');
ax4 = axes(tab2);
rfplot(ax4,imt2,1005e6)

Visualize Spur and Spur-Free Zones of IMT Mixer

Since R2024a

Create a mixerIMT object and specify the IMT data.

m = mixerIMT(IMT= [99 17 11.6; 40 0 44.7; 51.4 58.5 61.3]);

Specify the RF bandwidth as 120 MHz and the IF bandwidth as 10 MHz as inputs to the rfplot function in order to visualize the spur and spur-free zones of the mixerIMT object.

rfplot(m,"Frequency",3.1e9,"RFBW",120e6,"IFBW",10e6)

Input Arguments

imt — IMT mixer object

mixerIMT object

IMT mixer object, specified as a mixerIMT object.

Data Types: object

frequency — Input frequency of IMT mixer object

positive scalar

Input frequency of the IMT mixer object, specified as a positive scalar in Hz.

Data Types: double

ax — Axes to plot mixer spurs

axex object

Axes to plot mixer spurs, specified as an axes object.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: rplot(imt,2.1e9,RFBW=100e6)

RFBW — Radio frequency bandwidth

positive scalar

Since R2024a

Radio frequency (RF) bandwidth, specified as a positive scalar in Hz.

IFBW — Intermediate frequency bandwidth

positive scalar

Since R2024a

Intermediate frequency (IF) bandwidth, specified as a positive scalar in Hz.

Note

• You must specify IFBW with the RFBW name-value argument.

• If you do not specify IFBW with the RFBW argument, then the rfplot function assumes IFBW = RFBW.

Tips

In addition to plotting the mixer spurs, you can also use the rfplot function to:

• Plot the S-parameter data.

• Plot the cumulative RF budget result versus the cascade input frequency.

• Plot the input reflection coefficient and transducer gain of a matching network.

Version History

Introduced in R2022a

R2024a: Visualize spur and spur-free zones in IMT mixer using rfplot and RF Budget Analyzer app

You can now use the rfplot function or the RF Budget Analyzer app to visualize the spur and the spur-free zones in a mixerIMT object.