A true dc RF switch

Until now, RF engineers had no choice but to use MEMS or mechanical relays to operate at dc. Despite these technologies’ problems with reliability, flexibility, and size, no silicon vendor was able to provide RF switches in the lowest portion of the frequency spectrum: true dc, or 0 Hz.

Last January, Peregrine Semiconductor announced the industry’s first and only RF-integrated switch that operates at true dc: the PE42020, an RF switch built using the company’s UltraCMOS process. This single-chip, single-pole/double-throw (SPDT) switch not only operates from dc all the way up to 8 GHz, handling 30 dBm at 0 Hz and 36 dBm at 8 GHz, but switches in 10 µs and settles in 35 µs — more than 150 times faster than most MEMS and mechanical-relay systems. And it reduces costs by using standard logic voltages on the control pins.