Paolo Orsatti

A 20-mA-receive, 55-mA-transmit, single-chip GSM transceiver in 0.25-/spl mu/m CMOS

This paper presents a low-power 900-MHz GSM transceiver developed in a 0.25-/spl mu/m CMOS technology. The superhet receiver, with a single intermediate frequency at 71 MHz, has an overall worst case noise figure of 8.1 dB, including all filters. The overall gain can be digitally controlled over 98-dB range. The receiver consumes only 19.5 mA from the 2.5-V voltage supply while achieving the required blocking and intermodulation performance. The direct conversion transmitter has a fully integrated phase shifter and provides a 2-mW signal to the power amplifier with a low level of spurious emissions. The transmitted Gaussian minimum shift keying signal has an RMS average phase error <2/spl deg/, and the overall current consumption of the transmitter is 55 mA.

GSM transceiver front-end circuits in 0.25-μm CMOS

So far, CMOS has been shown to be capable of operating at RF frequencies, although the inadequacies of the device-level performance often have to be circumvented by innovations at the architectural level that tend to shift the burden to the circuit building blocks operating at lower frequencies. The RF front-end circuits presented in this paper show that excellent RF performance is feasible with 0.25 μm CMOS, even in terms of the requirements of the tried-and-true superheterodyne architecture. Design for low noise and low current consumption targeted for GSM handsets noise figures, a double-balanced mixer with 12.6dB SSB NF, as well as sub-25mA current consumption for the RF front-end (complete receiver), are among the main achievements.

A 20 mA-receive 55 mA-transmit GSM transceiver in 0.25 /spl mu/m CMOS

In a typical GSM handset, the battery takes as much as 20% of the cost, as well as volume and weight. Power consumption, which dictates the required battery size, is one of the most important considerations in design of transceiver ICs. Typical current consumption of BJT transceiver ICs reported in previous ISSCCs is 50 mA for 900 MHz GSM. This CMOS transceiver consumes less than 20 mA in the receive mode, despite the lower g/sub m//I ratio inherent to MOS transistors. Although external components are used where performance is critical, elimination of unnecessary passives makes their count low by present commercial standards. The receiver architecture is a single-IF (71MHz) superheterodyne, with interstage filter between the LNA and mixer for image reject and blocking performance. RF filter insertion losses make it necessary to have a LNA NF no more than 2dB and mixer NF no more than 15dB, to maintain 9dB overall receiver NF.

21.7 A 0.036mbar circadian and cardiac intraocular pressure sensor for smart implantable lens

Glaucoma is worldwide acknowledged to be the main leading cause of irreversible blindness. High intraocular pressure (IOP) is considered the leading risk factor for glaucoma. Lowering IOP continues to be the only evidence-based treatment to prevent its development or reduce the progression rate.