The switch IC is intended for use in handsets which incorporate tri-band WCDMA and quad-band EDGE platforms. This is an architecture which demands seven radios in a single handset. 

According to Peregrine, this complicates the RF front-end by more than tripling the number of high power signal paths in quad-band EDGE handsets. "Because switching signals to and from a duplexer and filter banks are utilised in these next-generation designs, the burden to the switching function becomes high," said the company.

Design requirements for multi-path front-end are low insertion loss due to the signal going through two switch paths, high linearity due to its WCDMA platform, a switch for four independent signal paths and isolation greater than +55dB for critical paths.

Peregrine's all CMOS-based PE42110 has linearity of +71dBm IP3 or -116dBm IMD3, low insertion loss of 0.35dB (typ) and high isolation greater than 70dB at critical paths. Three control lines operate 12 independent paths. 

The chip uses the firm's UltraCMOS mixed-signal process technology which is a variation of silicon-on-insulator (SoI) technology on a sapphire substrate. The process has been enhanced to allow for extremely linear FETs which when stacked together brings device linearity in to line with specifications required by the 3GPP standards body for GSM/WCDMA applications.

The 50ohm 2.75V RF switch operates from 100MHz to 3GHz. Features include 1500V HBM ESD tolerance at all ports, on-board CMOS logic which facilitates 1.8V or 2.75V control, no blocking capacitors and fast switch settling time.

See www.admiral-microwaves.co.uk