Mixer

Performance Parameters

• Gain (convolution analysis)• Port-to-Port Feedthrough• (Noise)• (Linearity)

Feedthrough Mechanism in a Mixer

(LO re-radiation)

Single Ended Pasive RF Mixer

Frequency Spectrum

LO

RF

LO-RF Feedthrough

Differential Mixer

Waveform

Voutp-Voutn

Frequency Spectrum

ComparisonReduced RF FeedthroughReduced DC Offset

Double Balanced Passive Mixer

Waveforms

Frequency Spectrum

No DC, RF, and LO Feedthrough

Output Waveform

Sampling Mixer

Sampling Mixer

Rf: 100 Hz, LO: 400 Hz

Waveform of Sampling Mixer

DFT of the Output Spectrum

Use PMOS to Improve Sampling

Improved Sampling Due to PMOS

Output Spectrum of CMOS Switch