FMCW Radar With Enhanced Resolution and Processing Time by Beam Switching

Abstract

We present the design of a novel K-band radar architecture for short-range target detection. Applications include direction finding systems and automotive radar. The developed system is compact and low cost and employs substrate-integratedwaveguide (SIW) antenna arrays and a 4×4 Butler matrix (BM) beamformer. In particular, the proposed radar transmits a frequency modulated continuous-wave (FMCW) signal at 24 GHz, scanning the horizontal plane by switching the four input ports of the BM in time. Also, in conjunction with a new processing method for the received radar signals, the architecture is able to provide enhanced resolution at reduced computational burden and when compared to more standard single-input multipleoutput (SIMO) and multiple-input multiple-output (MIMO) systems. The radar performance has also been measured in an anechoic chamber and results have been analyzed by illuminating and identifying test targets which are 2 • apart, while also making comparisons to SIMO and MIMO FMCW radars. Moreover, the proposed radar architecture, by appropriate design, can also be scaled to operate at other microwave and millimeterwave frequencies, while also providing a computationally efficient multi-channel radar signal processing platform.

A millimeter-wave automotive radar with high angular resolution for identification of closely spaced on-road obstacles

“…To recognize targets, various kinds of higher resolution millimeter-wave radars have been studied. A beam switching method was introduced in 10 , a radar imaging and neural network were used in 11 to characterize road surfaces, and wide aperture and cascading radar units were employed in 12 , 13 and 14 , 15 , respectively. Leak mitigation has been considered in 16 .…”

“…However, all of these studies require large-scale hardware and complicated signal processing. For example, 10 need additional circuitries for transmit antenna beam switching. 12 – 14 and 15 are much larger than a 3T X –4R X MIMO radar with a single radar IC.…”

Improving the Detection Capability of Imaging MIMO Radars by TX Beamforming

“…In this case, the complexity of the hardware is increased, as multiple digital-to-analog converters and modified transceivers are required. This requirement has been relaxed in [11], where a Butler matrix is used to switch between different predefined beams. With the previous generation of automotive radar transceivers, Tx beamforming can only be used to achieve a directional gain at boresight to increase the signal-to-noise ratio (SNR) for distant objects, since no phase difference can be set between the antennas.…”