Search

This brief presents a variable-gain amplifier (VGA) for automotive radar applications integrated in a 28-nm fully depleted (FD) silicon-on-insulator (SOI) CMOS technology. The amplifier operates at a power supply as low as 1 V and guarantees 30-dB linear-in-dB gain variation with a 3-dB step. The back-gate of the MOS transistors has been exploited to implement a back-gate control-based offset cancelation loop, thus avoiding the use of inter-stage coupling capacitors that introduce frequency limitations due to parasitic capacitances. The VGA exhibits a bandwidth from 100 kHz to 20 MHz, which is compliant with typical frequency-modulated continuous wave (FMCW) radars. It also guarantees a 1-dB compression point (${P} _{\mathrm{ 1dB}}$) better than −36 dBm and an input-referred noise (IRN) of 12.5 nV/ $\surd $ Hz and 7 nV/ $\surd $ Hz at 1 MHz and 10 MHz, respectively, with a power consumption as low as 1.7 mW. [ABSTRACT FROM AUTHOR]

This brief presents a fully CMOS voltage reference based on a self-biased topology, which provides low current consumption while saving silicon area. Temperature compensation is achieved by means of a subthreshold triode-based Widlar current reference and a proper arrangement of an active load. The proposed voltage reference was fabricated in a standard 0.13- $\mu {\text{m}}$ CMOS technology and occupies a core area as low as 0.003 mm2. The circuit properly operates with a power supply ranging from 2.4 V to 1.1 V while providing a reference voltage of around 800 mV with an average temperature coefficient of 100 ppm/°C and an overall current consumption below 25 nA. This performance makes the proposed voltage reference very suitable for RF-powered applications. [ABSTRACT FROM AUTHOR]

This brief demonstrates a fully contactless wafer-level testing based on UHF radio identification (RFID) technology enriched by high-quality on-chip antenna. The antenna, which uses exactly the same tag IC area (i.e., 0.45 mm2), exploits a low-cost post-process consisting of a thick dielectric layer and a copper metal, thus significantly improving the quality factor with respect to a standard CMOS implementation. Contactless wafer-level testing of a tag array is performed by simultaneous inductive coupling with a customized near-field reader. With a 27-dBm standard UHF RFID reader, a reading range up to 2.5 mm is demonstrated at 865 MHz. Anti-collision algorithm and memorized x–y device coordinates allow IC identification on the wafer under test to be achieved. Thanks to its cost-effectiveness, the proposed approach can be easily extended to general purpose IC contactless testing. [ABSTRACT FROM AUTHOR]

An ultra-low power voltage reference circuit is presented, which is based on proportional (PTAT) and complementary (CTAT) to absolute temperature current generation and performs current-mode voltage reference with first-order temperature compensation. Thanks to the use of subthreshold CMOS transistors and an operational amplifier, the circuit achieves low sensitivity to power supply variations while providing low voltage capability. Measurements show that the proposed circuit provides a reference voltage of around 597 mV and correctly operates with a supply voltage ranging from 3.3 V to 1 V and temperature variations from −40 to 85 °C. The overall current consumption is below 1 μA, thus making it suitable for RF-powered and ultra-low power sensor network applications. The chip was fabricated in a standard 0.13-μm CMOS technology and occupies a core area as low as 0.02 mm 2 . [ABSTRACT FROM AUTHOR]