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MEMS
phase shifters
Updated January
5, 2010
Click
here to go to our main page on phase shifters
Click
here to go to our page on PESAs
New for January 2010!
MEMS phase shifters has been an "active" area of research
for many years. That was a joke, get it? MEMS phase shifters are
passive!
MEMS phase shifters always brag
about low loss; indeed, they have lower loss than comparable MMIC
technology. But MEMS technology in general has a lot of problems,
which are described here.
MEMS are processed on many different
substrates, such as alumina, glass, high-resistivity silicon. But
the "magic" of creating that wonderful, movable strap,
the MEMS process teams usually omit two key elements of microwave
thin-film circuitry: thin-film capacitors, and thin-film resistors.
Without capacitors for matching networks, MEMS phase shifter designers
are stuck using crude architectures that ensure wide phase variation
with frequency, and undesirable
characteristic for a phased array.
The switching time of a MEMS
phase shifter is on the order of 1 microsecond, 1000 times slower
than most MMIC phase shifters.
More to come!
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