Manolis Terrovitis

Noise in current-commutating CMOS mixers

A noise analysis of current-commutating CMOS mixers, such as the widely used CMOS Gilbert cell, is presented. The contribution of all internal and external noise sources to the output noise is calculated. As a result, the noise figure can be rapidly estimated by computing only a few parameters or by reading them from provided normalized graphs. Simple explicit formulas for the noise introduced by a switching pair are derived, and the upper frequency limit of validity of the analysis is examined. Although capacitive effects are neglected, the results are applicable up to the gigahertz frequency range for modern submicrometer CMOS technologies. The deviation of the device characteristics from the ideal square law is taken into account, and the analysis is verified with measurements.

Intermodulation distortion in current-commutating CMOS mixers

The nonlinearity behavior of CMOS current-switching mixers is investigated. By treating the mixer as a periodically-time-varying weakly nonlinear circuit, we study the distortion-causing mechanisms and we predict the mixer distortion performance. Normalized graphs are provided from which the designer can readily estimate the mixer nonlinearity for particular process and design parameters. A simple CMOS transistor model appropriate for our calculations, which also takes into account deviation from the square law is adopted. The significance of a physical transistor model for reliable distortion simulation is demonstrated. The prediction of our analysis is compared with simulation results and with experimental data.

A single-chip dual-band tri-mode CMOS transceiver for IEEE 802.11a/b/g wireless LAN

A single-chip dual-band tri-mode CMOS transceiver that implements the RF and analog front-end for an IEEE 802.11a/b/g wireless LAN is described. The chip is implemented in a 0.25-/spl mu/m CMOS technology and occupies a total silicon area of 23 mm/sup 2/. The IC transmits 9 dBm/8 dBm error vector magnitude (EVM)-compliant output power for a 64-QAM OFDM signal. The overall receiver noise figure is 5.5/4.5 dB at 5 GHz/2.4 GHz. The phase noise is -105 dBc/Hz at a 10-kHz offset and the spurs are below -64 dBc when measured at the 5-GHz transmitter output.

An 802.11g WLAN SoC

A single-chip IEEE 802.11g-compliant WLAN radio that implements all RF, analog, and digital PHY and MAC functions is implemented in a 0.18 /spl mu/m CMOS technology. The IC transmits 4 dBm EVM-compliant output power for a 64QAM OFDM signal. The overall receiver sensitivities are -95 dBm and -73 dBm for data rates 6 Mbit/s and 54 Mbit/s, respectively.

A single-chip dual-band tri-mode CMOS transceiver for IEEE 802.11a/b/g WLAN

A 2.4/5 GHz transceiver implements the RF and analog front-end of an IEEE 802.11a/g/b WLAN system in 0.25 /spl mu/m CMOS technology. The IC transmits 9 dBm/8 dBm EVM-compliant output power at 5 GHz/2.4 GHz for a 64QAM OFDM signal. The overall receiver NF is 5.5/4.5 dB at 5/2.4 GHz.

A 1.9GHz Single-Chip CMOS PHS Cellphone

A single-chip CMOS PHS cellphone, fabricated in a 0.18mum CMOS process, implements all handset functions including radio, voice, audio, CPU, and digital interfaces. The IC has +4dBm EVM-compliant transmit power, -106dBm receiver sensitivity, and 15mus synthesizer settling time. It draws 81 mA from a 1.8V supply while occupying 35mm2 of chip area

A 3.2 to 4 GHz, 0.25 /spl mu/m CMOS frequency synthesizer for IEEE 802.11a/b/g WLAN

A fully integrated 3.2 to 4 GHz frequency synthesizer, part of an IEEE 802.11a/b/g transceiver, is implemented in a 0.25 /spl mu/m standard CMOS technology. The phase noise is -105 dBc/Hz at 10 kHz offset, and the spurs are below -64 dBc when measured at the 5 GHz transmitter output. The settling time is less than 150 /spl mu/s.

Cyclostationary noise in radio-frequency communication systems

Because of the periodically time-varying nature of some circuit blocks of a communication system, such as the mixers, the noise which is generated and processed by the system has periodically time-varying statistics. An accurate evaluation of the system output noise is not straightforward as in the case where all the circuit blocks are linear-time-invariant and the noise that they generate is time-independent. We qualitatively examine here, conditions under which we can treat the noise at the output of every circuit block of a practical communication system as if it were time-invariant, in order to simplify the noise analysis without introducing significant inaccuracy in the noise characterization of the overall communication system.

Design and implementation of a CMO 802.11n SoC

Wireless local area networks based on the IEEE 802.11 standard are rapidly replacing wires within homes and offices. The latest data-rate amendment to the IEEE 802.11 standard, known as the 802.11n, provides enhanced user experience by exploiting MIMO techniques that use multiple antennas for both transmitter and receiver. In conjunction with MAC layer improvements such as aggregating data, the 802.11n standard supports PHY data rates as high as 600 Mb/s with four spatial streams. This article discusses various MAC and PHY level modifications introduced in 802.11n, as well as the architecture, design trade-offs, and implementation details of a two spatial stream CMOS 802.11n-draft-compliant SoC.

A 65nm dual-band 3-stream 802.11n MIMO WLAN SoC

The rapid commercialization of the IEEE 802.11n WLAN standard has increased the demand for higher data-rate and longer-range fully integrated MIMO SoCs that are backward-compatible with legacy IEEE 802.11a/b/g networks. This paper introduces a 3-stream, 3×3 MIMO WLAN SoC that utilizes three antennas to improve throughput, range, and link robustness. This chip integrates three dual-band transceivers, digital physical layer, media access controller, and a PCI express interface in a 65nm CMOS process. Improved EVM is achieved by reducing transmit and receive I/Q mismatch with calibration, and reducing the integrated phase noise with a reference clock doubler.