What's a mixer? It's a device that performs the task of frequency conversion, by multiplying two signals (why do you think that the schematic symbol for a mixer is an "X"?) Mixers are needed in most microwave systems because the RF signal is way too high to process its information (for example, looking for a Doppler shift in an X-band radar application, you won't find many A/D converters than can handle 10 GHz!)
Please note:
By downloading a white paper, the details of your profile might be shared with the creator of the content and you may be contacted by them directly.