Technique for Integration of a Wireless Switch in a 2.4 GHz Single Chip Radio

A technique for integrating a wireless switch into an M&M™ sized radio operating at 2.4 GHz that can turn a radio on or off is demonstrated using a 130-nm digital CMOS process. The switch circuit like a passive radio frequency identification system picks up an amplitude modulated 5.8-GHz carrier and converts it to DC to power up a portion of radio connected to a coin-cell battery. The radio uses a 2.4/5.8 GHz dual band antenna, and the wireless switch is added between the antenna, and transmit/receive (T/R) switch of the radio. By incorporating an input impedance transformation network, the wireless switch achieves input sensitivity of~ -13~dBm. Inclusion of this circuit degrades the maximum transmitted power and sensitivity of 2.4-GHz transceiver by 0.3–0.5 dB. The RF clamp of wireless switch also limits the input power above~ 12~dBmto protect the switch and transceiver. The wireless switch occupies an area of~ 400× 590~μm².