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This article presents a 24/77-GHz transmitter chipset for automotive radar sensors implemented in a 160/175-GHz fT/fmax SiGe BiCMOS technology. The chipset adopts a dual-band architecture consisting of a 24-GHz section for ultra-wideband short-range radar operation, which is also exploited to drive the 77-GHz long-range radar transmitter front-end. The proposed design adopts a single 24-GHz frequency synthesizer to implement both radar operation modes. The transmitter chipset is able to deliver a maximum output power of 3 dBm and 12 dBm at 24 GHz and 77 GHz, respectively. The 24-GHz transmitter demonstrates to operate with pulse widths of 0.5 ns and 1 ns in compliance with the transmission mask designed by ETSI. The 77-GHz transmitter exhibits a power gain of 20 dB, an output power of 12 dBm, and an output referred 1-dB compression point of 9.5 dBm, while drawing 155 mA from a 2.5-V supply voltage. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:782-786, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27425 [ABSTRACT FROM AUTHOR]

This paper presents a Colpitts-based voltage-controlled oscillator (VCO) for W-band radar applications. In the proposed circuit, the oscillation signal is directly drawn from the switching transistor bases by means of the primary winding of a transformer tank, while the secondary winding drives the output buffer. This solution improves both tuning range and oscillation swing with respect to traditional millimeter-wave VCO topologies without increasing power supply. The oscillator is implemented in a 0.13-\mu\ m SiGe BiCMOS technology, along with high-frequency dividers to enable low-frequency testing. The VCO exhibits a phase noise of -\99.3 dBc/Hz at 1-MHz offset from an oscillation frequency of 76 GHz and a tuning range of 4.9% with a consumption of 65 mW at 2.5-V power supply. The VCO is also used to drive a two-stage power amplifier in a fully integrated W-band transmitter that is able to deliver an overall output power as high as 15 dBm at 76 GHz. [ABSTRACT FROM AUTHOR]

This paper presents a 15-dBm power amplifier for 77-GHz automotive radar applications, which is fabricated in a 0.13-\mu\ m SiGe:C BiCMOS process featuring bipolar transistors with f T / f\max of 230/280 GHz. The circuit consists of a two-stage pseudodifferential cascode with fully integrated input/output matching networks. State-of-art performance is achieved with the proposed design algorithm and layout optimization. The amplifier demonstrates a figure-of-merit of 2500 achieving a 22.5-dB power gain and a power-added efficiency of 7.5% at 77 GHz, while drawing 130 mA from a 2.5-V voltage supply. [ABSTRACT FROM AUTHOR]

This letter presents a 77-GHz power amplifier implemented in a SiGe BiCMOS technology featuring bipolar transistors with 160/175-GHz f/ f. The circuit adopts a two stage differential topology with integrated input/output matching networks. The amplifier performance is considerably improved thanks to proper input/output LC resonant networks, which cancel out the ground-plane parasitic effect. Matching networks use stacked transformers for impedance matching, differential-to-single-ended conversion, and electro-static discharge protection. The circuit achieves a power gain of 18.5 dB, a maximum output power of 11.6 dBm, with 4.2% power-added efficiency, and an output 1-dB compression point of 9.3 dBm. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1413-1416, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25972 [ABSTRACT FROM AUTHOR]

n amplifier topology based on a transformer-coupled cascode stage is presented and compared with the most used solutions for sub-μm CMOS power amplifiers, which are the common-source stage, cascode stage, and capacitive-coupled cascode stage. The comparison was carried out by designing each amplifier in a 65-nm CMOS technology and for a 60-GHz operating frequency. The design was optimized for a trade off among power gain, saturated output power, and linearity. Operating from a 1.2-V supply voltage, the proposed amplifier improves both small-signal and large-signal performance with respect to the most common approaches, thus demonstrating effectiveness with sub-μm CMOS technologies and mm-wave operation. [ABSTRACT FROM AUTHOR]

In this letter, a novel structure for mm-wave integrated transformers is presented. The proposed transformers, namely, interstacked, exploit mixed interleaved/stacked coils, which allow increasing the magnetic coupling with respect to stacked devices, providing full geometrical/electrical symmetry. An extensive comparison between interstacked and conventional structures demonstrates the benefits of the proposed configuration in terms of the most significant figures of merit for integrated transformers. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2160–2163, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25385 [ABSTRACT FROM AUTHOR]

This paper presents a variable-gain amplifier (VGA) in the 68–78 GHz range. To reduce DC power consumption, the drain voltage was set to 0.5 V with competitive performance in the gain and the noise figure. High-Q shunt capacitors were employed at the gate terminal of the core transistors to move input matching points for easy matching with a compact transformer. The four stages amplifier fabricated in 40-nm bulk complementary metal oxide semiconductor (CMOS) showed a peak gain of 24.5 dB at 71.3 GHz and 3‑dB bandwidth of more than 10 GHz in 68–78 GHz range with approximately 4.8-mW power consumption per stage. Gate-bias control of the second stage in which feedback capacitances were neutralized with cross-coupled capacitors allowed us to vary the gain by around 21 dB in the operating frequency band. The noise figure was estimated to be better than 5.9 dB in the operating frequency band from the full electromagnetic (EM) simulation. [ABSTRACT FROM AUTHOR]