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

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

In this paper, a 77-GHz radar receiver is presented, which comes in a wafer level package and thus eliminates the need for wire bonding yielding significant cost reduction. The high integration level available in the productive Silicon-Germanium (SiGe) technology used in this paper allows for implementation of in-system monitoring of the receiver conversion parameters. This facilitates the realization of ISO 26262 compliant radar sensors for automotive safety applications.

A 77GHz automotive radar receiver in a wafer level package

A low-power FMCW 80 GHz radar transmitter front-end chip is presented, which was fabricated in a SiGe bipolar production technology ( fT=180 GHz, fmax=250 GHz ). Additionally to the fundamental 80 GHz VCO, a 4:1-frequency divider (up to 100 GHz), a 23 GHz local oscillator (VCO) with a low phase noise of -112 dBc/Hz (1 MHz offset), a PLL-mixer and a static frequency divider is integrated together with several output buffers. This chip was designed for low power consumption (in total <; 0.5 W, i.e., 100 mA at 5 V supply voltage), which is dominated by the 80 GHz VCO due to the demands for high output power (≈ 12 dBm) and low phase noise (minimum -97 dBc/Hz at 1 MHz offset) within the total wide tuning range from 68 GHz to 92.5 GHz (Δf = 24.5 GHz). Measurements of the double-PLL system at 80 GHz showed a low phase noise of -88 dBc/Hz at 10 kHz offset frequency.

A Low-Power Wideband Transmitter Front-End Chip for 80 GHz FMCW Radar Systems With Integrated 23 GHz Downconverter VCO

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

A charge pump driver circuit (320) arranged to output a charge pump control signal (325). The charge pump driver circuit (320) includes a bias current source component (330) arranged to generate a bias current (335), a control stage (340) and an output stage (350). The control stage (340) is coupled to the bias current source component (330) and arranged to receive the bias current (335). The control stage (340) is further arranged to receive an input signal (215) and to generate a control current signal (345) proportional to the bias current (335) in accordance with the input signal (215). The output stage (350) is arranged to receive the control current signal (345) generated by the control stage (340) and to generate the charge pump control voltage signal (325) based on the control current signal (345) generated by the control stage (340). The bias current source component (330) is arranged to vary the bias current (335) in response to variations in temperature.

Method and apparatus for generating a charge pump control signal

A wireless communication unit (300) comprises a transmitter having a power amplifier (324) biased by a bias circuit (350) and a controller (314) operably coupled to the bias circuit (350) for setting one or more bias levels of the power amplifier (324). The bias circuit (350) is a single bias circuit and is configured to provide either a current mode bias control of the power amplifier (324) or a voltage mode bias control of the power amplifier (324) in response to a control signal from the controller (314). In this manner, a single bias control circuit can be used to support applications that benefit from both current mode bias control and voltage mode bias control of the power amplifier (324).

Bias circuit for a radio frequency power-amplifier and method therefor

A radar device (100) is described that includes at least one transceiver (205) configured to support frequency modulated continuous wave (FMCW); a digital controller (262); and a temperature sensor system comprising a plurality of temperature sensors (222, 232, 242) coupled to various circuits (220, 230, 240) in the at least one transceiver (205). The digital controller (262) of the radar device (100) is configured to monitor a temperature of the various circuits (220, 230, 240) by polling temperature values of the plurality of temperature sensors (222, 232, 242).

Pierre Savary

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

Method and apparatus for generating a charge pump control signal

Bias circuit for a radio frequency power-amplifier and method therefor

Temperature sensor system, radar device and method therefor