Bouraima Boukari

A Heterodyne Six-Port FMCW Radar Sensor Architecture Based on Beat Signal Phase Slope Techniques

A Heterodyne six-port FMCW collision avoidance radar sensor conflguration based on beat signal phase slope techniques is presented in this paper. Digital IF circuitry has been used in order to avoid problems related to DC ofiset and amplitude and phase imbalance. Simulations show that the velocity and range to the target is obtained simultaneously, with very good accuracy. Results are compared to other techniques and system architectures.

MHMICs on ceramic substrate for advanced millimeter wave systems

This paper presents the initial design and fabrication results of several new passive millimeter wave circuits integrated on a thin ceramic substrate, having a relative permittivity of 9.9 and a thickness of 127 µm. The work is focused on a Wilkinson power divider, a 90° hybrid coupler, a rate-race coupler and two six-port circuits. Experimental results show wideband characteristics over the millimeter wave V and W bands, allowing therefore their use for high data-rate wireless communication systems and radar sensors.

Robust Microstrip-to-Waveguide Transitions for Millimeter-Wave Radar Sensor Applications

Two robust millimeter-wave microstrip-to-waveguide transitions are proposed in this paper. The central operating frequency is 77 GHz, for collision-avoidance radar applications. The microstrip line has been first transformed into an air-filled rectangular waveguide whose height is equal to the substrate thickness. Then, a conventional multisection lambda/4 transformer has been used in the first transition, and a patch antenna in the second transition, to transform to the feeding WR12 waveguide. Experimental results for the first transition show an insertion loss less than 2 dB and a return loss better than 15 dB in a bandwidth of 3 GHz for the back-to-back transition.

Millimeter-wave multi-port radar sensor with integrated receiver front-end for automotive applications

A 77 GHz prototype of heterodyne millimeter-wave radar sensor suitable for automotive applications is proposed and validated in this paper. A radar test bench is built using standard laboratory equipments with a waveguide transmitter and the integrated prototype receiver. A very good accuracy of relative speed detection (simulations) and range estimation (simulations and measurements) is obtained.

Six-Port Interferometric Technique for Accurate

An innovative six-port (SP) phase-noise measurement technique for millimeter-wave high-power sources is proposed in this paper. Simulation results using a 94-GHz rectangular waveguide SP circuit model validates the measurement principle for both millimeter-wave oscillators and amplifiers. Phase-noise measurement results of a 100-W extended interaction Klystron amplifier are presented and discussed. Compared to conventional methods, this new method allows accurate low-cost phase-noise measurements.

W

A 77GHz microstrip antenna array with a small surface providing high side and grating lobe suppression is presented. This may serve as a starting point for 77GHz automotive radar applications. Multiple Wilkinson dividers guarantee both impedance matching at the input port (TX) as well as low return loss for the incoming (RX) signal. Phase shifting is done by adjusting the level of the Wilkinson dividers or by meandered sections of transmission line. The in∞uence of the radiation caused by the feeding network is analyzed and the absolute degradation in side lobe suppression is derived in this paper.

-Band Phase-Noise Measurements

This paper presents two six-port 77 GHz FMCW collision avoidance radar sensor configurations. The first one uses a six-port double balanced mixer for direct frequency conversion and conventional frequency counting to determine the range and velocity of the target. The second one uses a six-port phase/frequency discriminator. Here velocity and range are determined in the same manner by evaluating the beat frequencies which are the slope of the instantaneous phase of the beat signals. Unlike other six-port collision avoidance sensors, measurement data processing techniques are developed to overcome the problems related to the DC current offset and amplitude imbalance, avoiding the need of six-port calibration. Computer simulation shows very good results for both configurations.

77 GHz MILLIMETER WAVE ANTENNA ARRAY WITH WILKINSON DIVIDER FEEDING NETWORK

A low cost millimeter-wave narrowband six-port double-balanced mixer circuit is proposed. Due to the symmetry and specific properties of the six-port, the mixer exhibits very good suppression of harmonic and spurious products. The mid operating frequency is selected to be 77 GHz, which is dedicated to collision avoidance radar for automobile applications. The simulation results show a conversion loss less than 4 dB and a very good linearity over a wide input power range. The 1 dB compression point and the third-order input intercept point are respectively 7.25 and 17 dBm.