This paper discusses concurrent design and analysis of the first 8.5 kV electrostatic discharge (ESD) protected single-pole ten-throw (SP10T) transmit/receive (T/R) switch for quad-band (0.85/0.9/1.8/1.9 GHz) GSM and multiple-band WCDMA smartphones. Implemented in a 0.18 μm SOI CMOS, this SP10T employs a series-shunt topology for the time-division duplex (TDD) transmitting (Tx) and receiving (Rx), and frequency-division duplex (FDD) transmitting/receiving (TRx) branches to handle the high GSM transmitter power. The measured P-0.1 dB, insertion loss and Tx-Rx isolation in the lower/upper bands are 36.4/34.2 dBm, 0.48/0.81 dB and 43/40 dB, respectively, comparable to commercial products with no/little ESD protection in high-cost SOS and GaAs technologies. Feed-forward capacitor (FFC) and AC-floating bias techniques are used to further improve the linearity. An ESD-switch co-design technique is developed that enables simultaneous whole-chip design optimization for both ESD protection and SP10T circuits.
- concurrent design