Frequency Conversion Mixer: Vin(t), LO(t), and Vout(t)

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Frequency Conversion Mixer: Vin(t), LO(t), and Vout(t) NEXMASON Science \& Technology

Mixer Principle

An ideal mixer multiplies the input and local-oscillator voltages: V_mix(t)=K V_in(t)V_LO(t). Multiplication produces the sum and difference frequencies. An output filter selects one component as V_out(t).

Downconversion

V_in(t)\ (10\,kHz) LO(t)\ (9\,kHz) mixer+filterV_out(t)\ (1\,kHz). Play the animation and compare all three synchronized voltage graphs. The two fast waves produce a visibly slower output wave.

Upconversion

V_in(t)\ (1\,kHz) LO(t)\ (9\,kHz) mixer+filterV_out(t)\ (10\,kHz). The slow input and fast LO produce a visibly faster output after the sum-frequency component is selected.

Conclusion

The three synchronized plots show the complete signal path directly: V_in(t) and LO(t) enter the mixer, and the selected frequency appears as V_out(t).