Alessandro Fonte

13 GHz CMOS Active Inductor LC VCO

A 13 GHz active inductor LC voltage controlled oscillator (VCO) has been realized in 90 nm CMOS technology by ST-Microelectronics. The VCO consists of two complementary cross-coupled pairs, an active LC tank implemented by means of a differential high-Q low-noise active inductor and two p-MOSFET varicaps, and an output buffer stage. The measurements show a phase noise of -105.25 dBc/Hz at 1 MHz frequency offset. The current consumption of the VCO core and differential boot-strapped inductor amount to 0.7 and 1.8 mA, respectively, from a 1.2 V supply voltage.

Microwave Active Inductors

In this letter, the experimental proofs of two microwave active inductors with very high quality factor, namely Differential Boot-Strapped Inductor (D-BSI) and Cross-Coupled Differential Boot-Strapped Inductor (CCD-BSI), are presented. These circuits can be effectively implemented in modern RF-CMOS processes for high-Q equivalent integrated inductors at high frequency. The cases of study at 13 GHz have been designed and implemented in a modern standard 90 nm bulk CMOS process. The measurements on the test-chips show an equivalent inductance close to 3.2 nH with an associated quality factor up to 400 and a wide linearity range.

System-on-chip microwave radiometer for thermal remote sensing and its application to the forest fire detection

This paper focuses on the opportunities offered by the latest advances in silicon technologies for realizing system-on-chip microwave radiometer. Such a highly integrated, low-cost, radiometer chip could be applied to the environmental remote sensing and, in particular, to the forest fire detection. The feasibility study is carried-out in two steps. First, a proof of the concept is given by means of a discrete-component radiometer operating at 12.65 GHz. This radiometer exploits TV-SAT components such as low-noise down-converter and dish antenna. On-field measurements shows a radiometric contrast (increase of the antenna noise temperature due to the fire with respect to the background) of about 8 K for a wooden fire of 0.38 m 2 placed 30 m away from the antenna. Then, a single-chip 13 GHz radiometer has been designed exploiting a CMOS 90 nm standard process. The sensor is based on a direct-conversion architecture with integrated LNA, Gilbertpsilas cell mixer and PLL frequency synthesizer. The IF chain includes an active (gm-C) low-pass filter and a CMOS square-law detector. The circuit simulations show a total receiver gain of 72 dB, an equivalent input noise temperature of 105 K and an IF bandwidth of 100 MHz.

Feasibility study and on-chip antenna for fully integrated μRFID tag at 60 GHz in 65 nm CMOS SOI

This paper reports the feasibility study of a novel passive tag for μRFID applications in the worldwide available free 60-GHz band. The feasibility analysis indicates that a passive fully-integrated μRFID tag, with on-chip antenna, can be realized in 65-nm SOI CMOS technology at 60 GHz with an operating range of about 20 cm. The 65-nm SOI CMOS technology represents a good candidate due to its better performance in terms of low-losses, low-power consumption and lower leakage current if compared with standard bulk process. The proposed circuit does not require complex package or bonding, thanks to the on-chip antenna, and it does not need battery. The low-cost technology and low-weight and low-area occupation are important features of this μRFID, especially if produced in large scale for the mass-market. Since the design of integrated antennas in silicon technology is one of the main challenge, especially for this proposal, two 60-GHz antennas have been designed by means of 3D-EM simulator: a CPW double-slot antenna and a CPS dipole one. The simulation results show a gain of 4.44 dBi and 3.23 dBi for the proposed double slot and dipole on-chip antennas, respectively.

Dual-Input Pseudo-Switch RF Low Noise Amplifier

A dual-input low noise amplifier (DILNA) topology with pseudo-switch capability is presented. This novel solution allows us to avoid the use of the RF switch in all cases in which the LNA input has to be switched alternatively between two different RF sources. This is obtained by duplicating the input stage of the LNA and creating two concurrent stages. In the particular case of 13-GHz radiometric applications, the DILNA circuit has been realized in 90-nm CMOS technology, and the measurement results have shown a noise figure of 2.5 dB, a power gain close to 19 dB from both inputs, an input-output isolation close to -60 dB, and an isolation between the two inputs of about -45 dB at 13 GHz. The power consumption amounts to 17.38 mW from a 1.1-V supply voltage. These results represent one of the best sets of performance among those presented in the literature.

CMOS microwave radiometer: Experiments on down-conversion and direct detections

This paper deals with the design of fully integrated, silicon microwave radiometers according to down-conversion and direct detections architectures. The low-noise amplification stages have been developed exploiting a state-of-the art 90 nm CMOS process, thus allowing a new class of miniaturized sensors (i.e. SoC microwave radiometers) to be conceived. The LNA developed for the down-conversion radiometric architecture has been fabricated and measured CMOS Microwave Radiometer: Experiments on showing, at 13 GHz, a power gain of 19 dB, a noise figure of 1.4 dB and a power consumption of 17.38 mW with 1.1-V supply. These figures represent one of the best set of performance among those presented, now-a-day, in the literature. Concerning the the direct detection radiometric architecture only post-layout simulations are reported. In this case the designed LNA reaches a power gain of 50 dB, a noise figure of 1.4 dB with an associated power consumption of 32 mW.

Advanced Model and RF-CMOS Design of the Boot-Strapped Inductor

This paper reports a new advanced design of the active circuit named boot-strapped inductor (BSI), which realizes an equivalent inductor with an high quality factor (Q). In particular, a new small-signal circuit model is proposed for an accurate design at high frequency in a modern RF CMOS process, also by taking into account the issues of an algorithmic and low-power consumption circuit design. A case study for 13-GHz low-power applications by using a standard for 90 nm CMOS process is reported. The BSI provides an equivalent inductance close to 1.6 nH with an associated quality factor Q close to 200.

Wearable System-on-a-Chip Radiometer for Remote Temperature Sensing and its Application to the Safeguard of Emergency Operators

The remote sensing and the detection of events that may represent a danger for human beings have become more and more important thanks to the latest advances of the technology. A microwave radiometer is a sensor capable to detect a fire or an abnormal increase of the internal temperature of the human body (hyperthermia), or an onset of a cancer, or even meteorological phenomena (forest fires, pollution release, ice formation on road pavement). In this paper, the overview of a wearable low-cost low-power system-on-a-chip (SoaC) 13 GHz passive microwave radiometer in CMOS 90 nm technology is presented. In particular, we focused on its application to the fire detection for civil safeguard. In detail, this sensor has been thought to be inserted into the fireman jacket in order to help the fireman in the detection of a hidden fire behind a door or a wall. The simulation results obtained by Ptolemy system simulation have confirmed the feasibility of such a SoaC microwave radiometer in a low-cost standard silicon technology for temperature remote sensing and, in particular, for its application to the safeguard of emergency operators.

Feasibility study and design of a low-cost system-on-a-chip microwave radiometer on silicon

A detailed system analysis of a novel low-cost system-on-a-chip (SoaC) passive microwave radiometer on silicon for civil and environmental safeguard applications is presented. Particularly, this paper focuses the opportunities offered by the latest advances silicon technology for realizing innovative integrated radiometer for temperature remote sensing and its application to the forest fire prevention. An accurate feasibility study of a SoaC radiometer on a standard CMOS process for the 13 GHz frequency range is reported. The potential of such a low-cost solution has been confirmed by the system analysis carried out by means of Ptolemy simulations.

Millimeter-wave high-Q CMOS active inductor

This paper presents a novel low-power high-Q active inductor, which exploits only an integrated transformer and a MOSFET in common drain configuration. The operating principle is explained and the equivalent input impedance is derived. The case study for millimeter-waves low-power applications has been implemented by using a standard 90-nm CMOS process. The active inductor provides an equivalent inductance close to 1.3 nH with an associated quality factor (Q) close to 250 at 34.6 GHz, with a power consumption of 354 µW and 500-mV supply voltage.