Mixer Performance Simulations: Difference between revisions
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***Run a short '''tran''' simulation to find the time when all of the voltages in your mixer have settled and there is no "ringing" | ***Run a short '''tran''' simulation to find the time when all of the voltages in your mixer have settled and there is no "ringing" | ||
**Click OK | **Click OK | ||
*In the Analog Design Environment, select '''pxf''' analysis (pxf stands for periodic transfer function) | |||
**Set '''Sweep type''' to '''default''' | |||
**Under '''Output Frequency Sweep Range (Hz)''' select '''Start-Stop''' | |||
**Set '''Start''' to '''1 MHz''' and '''Stop''' to '''400 MHz''' | |||
*Set the '''Sweep Type''' to '''Linear''' | |||
**Select '''Number of Steps''' and set the value to '''1000''' | |||
**Set '''Sidebands''' to '''Maximum Sideband''' and enter the value '''3''' | |||
**Under '''Output''' select '''probe''' and then selct the IF port | |||
**Click OK | |||
*Run the simulation | |||
*To view the results for the conversion gain simulatoin click <code>Results -> Direct Plot -> Main Form ...</code> | |||
**Set the '''Analysis''' to '''pxf''' | |||
**Set the '''Function''' to '''Voltage Gain''' | |||
**Set '''Sweep''' to '''sideband''' | |||
**Select sidebands -1 and 1 (hold down the '''ctrl''' key to select multiple sidebands) | |||
***This is the sideband that provides us the conversion gain of our RF frequency of interest | |||
**Set '''Modifier''' to '''dB20''' | |||
**Click on the RF port in the schematic | |||
Revision as of 13:57, 7 April 2011
Conversion Gain
- You must first instance ports for the RF, LO, and IF ports of the mixer (
analogLib -> Sources -> Independent -> port). If your mixer requires differential inputs/outputs then refer to the separate tutorial on how to drive differential signals. - Edit the properties of the RF port
- Set the Resistance to 50 Ω and the Port number to 1
- Set the Source type to dc
- Click OK
- Edit the properties of the LO port
- Set the Resistance to 50 Ω
- Set the Port number to 2
- Set the Source type to sine
- Fill in the flo for the Frequency name 1
- Frequency 1 should be either 2.2 GHz (for low-side injection) or 2.6 GHz (for high-side injection)
- This is the frequency of the local oscillator signal
- Fill in Amplitude 1 (Vpk) with the amplitude of your LO signal
- Click OK
- Edit the IF port
- Set the Resistance to 50 Ω and the Port number to 3
- Set the Source type to dc
- Click OK
- In the Analog Design Environment, enable the pss analysis
- Verify that only flo is displated in the Fundamental tones section
- Select Beat Frequency and click Auto Calculated
- Select Number of harmonics under Output harmonics and fill in the value of 0
- This number of ourput harmonics is required by the pxf analysis that we will use to perform the conversion gain simulation
- Set the Accuracy Defaults (errpreset) to conservative
- Set the Additional Time for Stabalizatoin (tstab) to a time larger that the settling time of your system
- Run a short tran simulation to find the time when all of the voltages in your mixer have settled and there is no "ringing"
- Click OK
- In the Analog Design Environment, select pxf analysis (pxf stands for periodic transfer function)
- Set Sweep type to default
- Under Output Frequency Sweep Range (Hz) select Start-Stop
- Set Start to 1 MHz and Stop to 400 MHz
- Set the Sweep Type to Linear
- Select Number of Steps and set the value to 1000
- Set Sidebands to Maximum Sideband and enter the value 3
- Under Output select probe and then selct the IF port
- Click OK
- Run the simulation
- To view the results for the conversion gain simulatoin click
Results -> Direct Plot -> Main Form ...- Set the Analysis to pxf
- Set the Function to Voltage Gain
- Set Sweep to sideband
- Select sidebands -1 and 1 (hold down the ctrl key to select multiple sidebands)
- This is the sideband that provides us the conversion gain of our RF frequency of interest
- Set Modifier to dB20
- Click on the RF port in the schematic