IEEE S.F. Bay Area Council e-GRID's
BayAreaTech

THURSDAY December 10, 2009
SCV Microwave Theory and Techniques Chapter
Speaker: Edmar Camargo, DBA Consulting
Time: Refreshments at 6:00 PM, Presentation at 6:30 PM
Cost: none
Place: Agilent, Building 1 Lobby, Aristotle Rm, 5301 Stevens Creek Blvd, Santa Clara
RSVP: not required
Web: www.ewh.ieee.org/r6/scv/mtt

Sub-harmonic mixers appeared in the early thirties as a solution to minimize LO radiation from super-heterodyne receivers, and to obtain higher effective LO frequencies.? However, their overall performance compared to fundamental mixers was far from desirable, so they did not receive the attention they deserved.? Despite the drawbacks, the concept had several revivals over the years mainly caused by technology developments from tubes to Schottky diodes on Silicon, high frequency bipolar devices, GaAs FETs, and most recently Silicon CMOS FETs.? In recent years the demand for wireless communications began favoring direct receiver approaches as a means to cut cost, but the old LO radiation problem surfaced again.? Fortunately, circuit technology also evolved over the years so that modern sub-harmonic mixers now have acceptable performance levels allowing their application into wireless systems. This presentation gives an overview of the evolution of sub-harmonic mixers and reports on the important milestones of this technology.