RF Electronics Chapter 5: Frequency Mixers Page 119
2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0.
Computer Simulation of Mixers
The advanced RF Computer simulation programs like MWO and ADS allow frequency
mixers to be simulated accurately. A frequency mixer requires two inputs, both at
different frequencies and the output is normally at a frequency that is different from both
the inputs to the mixer. The simulation is thus very different from that of a linear device,
like a transformer, hybrid or filter.
Figure 5.14. Typical Measurements for a mixer.
The Project Options menu sets the frequencies used for the simulation. For the single
diode mixer of figure 5.13 and 5.14, these frequencies are used by the PORT_PS1 port
element, which is applied to the LO port (Port 2). The PORT_PS1 element allows the
signal power to be varied as specified by the parameters for the PORT_PS1 element. A
PORTF element produces a single tone signal with frequency and power level set by the
parameters for that element. For a down-conversion mixer, the PORTF element is applied
to the RF port. The RF simulation will then use these frequency and power levels to
determine the time waveforms at the IF port, using a SPICE modelling of the diode and
the circuit. Figure 5.15 shows the project frequency and typical measurements settings
used for the mixer measurements to figure 5.41.
Figure 5.15. Project frequency and parameters for conversion loss measurements.
RF Electronics: Design and Simulation
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