A fully-integrated FMCW radar system for automotive applications operating at 77 GHz has been proposed. Utilizing a fractional- synthesizer as the FMCW generator, the transmitter linearly modulates the carrier frequency across a range of 700 MHz. The receiver together with an external baseband processor detects the distance and relative speed by conducting an FFT-based algorithm. Millimeter-wave PA and LNA are incorporated on chip, providing sufficient gain, bandwidth, and sensitivity. Fabricated in 65-nm CMOS technology, this prototype provides a maximum detectable distance of 106 meters for a mid-size car while consuming 243 mW from a 1.2-V supply.

A Fully-Integrated 77-GHz FMCW Radar Transceiver in 65-nm CMOS Technology

A radar system with an ultra-wide FMCW ramp bandwidth of 25.6 GHz (≈32%) around a center frequency of 80 GHz is presented. The system is based on a monostatic fully integrated SiGe transceiver chip, which is stabilized using conventional fractional-N PLL chips at a reference frequency of 100 MHz. The achieved in-loop phase noise is ≈ -88 dBc/Hz (10 kHz offset frequency) for the center frequency and below ≈-80 dBc/Hz in the wide frequency band of 25.6 GHz for all offset frequencies >;1 kHz. The ultra-wide PLL-stabilization was achieved using a reverse frequency position mixer in the PLL (offset-PLL) resulting in a compensation of the variation of the oscillators tuning sensitivity with the variation of the N-divider in the PLL. The output power of the transceiver chip, as well as of the mm-wave module (containing a waveguide transition), is sufficiently flat versus the output frequency (variation <;3 dB). In radar measurements using the full bandwidth an ultra-high spatial resolution of 7.12 mm was achieved. The standard deviation between repeated measurements of the same target is 0.36 μm.

An Ultra-Wideband 80 GHz FMCW Radar System Using a SiGe Bipolar Transceiver Chip Stabilized by a Fractional-N PLL Synthesizer

Concept, design, and measurement results of a frequency-modulated continuous-wave radar sensor in low-temperature co-fired ceramics (LTCC) technology is presented in this paper The sensor operates in the frequency band between 77–81 GHz As a key component of the system, wideband microstrip grid array antennas with a broadside beam are presented and discussed The combination with a highly integrated feeding network and a four-channel transceiver chip based on SiGe technology results in a very compact LTCC RF frontend (23 mm $\times$ 23 mm) To verify the feasibility of the concept, first radar measurement results are presented

A 79-GHz Radar Sensor in LTCC Technology Using Grid Array Antennas

A millimeter-wave (mm-wave) frequency synthesizer is presented focusing on an ultra-high-speed fractional- ${ N}$ frequency divider and a highly linear phase-frequency detector (PFD). All circuits are integrated into a high-frequency SiGe bipolar technology. The programmable frequency divider can be operated at input frequencies between dc and 57 GHz for division factors in the entire integer range from 12 to 259. The PFD is optimized for fractional- ${ N}$ synthesis, which requires an extremely linear characteristic due to the modulation of its input frequency. The frequency divider and the PFD are used together with an 80-GHz wideband voltage-controlled oscillator (VCO) and transceiver for a high precision mm-wave frequency-modulated continuous-wave (FMCW) radar sensor. As shown by the experimental results the realized circuits stabilize the mm-wave VCO with an extremely low phase noise below $-{\hbox{97 dBc/Hz}}$ at 10-kHz offset around its center frequency of 80 GHz and can generate a highly linear frequency ramp with a bandwidth of 24 GHz. Furthermore, the accuracy of the synthesizer is demonstrated by FMCW radar distance measurements inside a waveguide and in free space. Inside the waveguide a standard deviation of the phase of the target below 0.0018 $^{\circ }$ (which corresponds to 9.4 nm) was measured.

A SiGe Fractional- ${ N}$ Frequency Synthesizer for mm-Wave Wideband FMCW Radar Transceivers

An integrated circuit comprises frequency generation circuitry for controlling a frequency source for an automotive radar system The frequency generation circuitry comprises a Phase Locked Loop (PLL) arranged to generate a control signal for controlling the frequency source, a fractional-N divider located within a feedback loop of the PLL, and frequency pattern control logic operably coupled to the fractional-N divider and arranged to control the fractional-N divider, by way of a frequency control signal, such that the PLL generates a Frequency Modulated Continuous Wave (FMCW) control signal

Integrated circuit comprising frequency generation circuitry for controlling a frequency source

A single chip transmitter for automotive FMCW radar application is implemented in 0.18um SiGe BiCMOS technology.

A fully integrated 77GHz FMCW radar transmitter using a fractional-N frequency synthesizer

Recent advancements in SiGe device development enable the realization of 77GHz automotive radar systems using relatively low-cost silicon technology. This paper will discuss technology requirements for the radar design and also present examples of receiver and transmitter circuit implementations.

SiGe technology and circuits for automotive radar applications

An XOR phase detector for a phase-locked loop PLL comprises an XOR gate which has an input for a periodic reference signal and another input connected to a frequency divider of the PLL. A level shifter has a level shifter input connected to an output of the XOR gate and a level shifter output connectable to a voltage-controlled oscillator VCO of the PLL. The level shifter is connectable between low and high voltage providers and has a high level and a low level. The level shifter is arranged to deliver at its output the high level or the low level depending on whether the voltage at the output of the XOR phase detector is low or high. The level shifter further has a setpoint input for setting the high level to a setpoint level.

XOR phase detector, phase-locked loop, and method of operating a PLL

calculate and apply a gain offset dependent upon the selected gain that is adapted when the selected gain is changed.

Didier Salle

Papers

Integrated circuit comprising frequency generation circuitry for controlling a frequency source

A fully integrated 77GHz FMCW radar transmitter using a fractional-N frequency synthesizer

SiGe technology and circuits for automotive radar applications

XOR phase detector, phase-locked loop, and method of operating a PLL

Digital synthesizer, communication unit and method therefor