Automotive Radar Dismantling and Cost Analysis, 2019-2020
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It is in this report that over a dozen of millimeter-wave radar types are studied on design, supply chain and cost, including Continental's ARS4A, ARS4B, ARS408 and ARS410, Bosch's LRR4, FR5CP, MRR1PLUS and MRR Rear, Aptiv's RACam and SRR3, Veoneer's MRRV1, Valeo's MBHL2, ZF's AC1000, Denso's HYQDNWR010, etc. Some of them are dismantled and illustrated in details.
Automotive MMW radar is mainly comprised of a planar printed antenna, RF IC (generally called MMIC) and DSP-contained MCU. The fast Fourier transformation (FFT) of radar is a special operation, mostly fulfilled by separate external FPGA or DSP in the past. Freescale built DSP into MCU for the first time, improving the integration observably. Also, there are a few external DSP designs for the time being. Auxiliary IC encompasses power management, VCO, low-noise amplifier LNA, CAN transceiver, among others. MCU is often offered by NXP's 577x series or 567x series.
MMIC, though with a small share in costs, is crucial to both total cost and performance, really making a big difference in costs between radars. For example, the MR2001 radar chipset consists of two transmitters and three receivers. A simple mid-range radar only needs a chipset, but a long-range radar with higher resolution demands more chipsets, like ARS 4A with one more transmitter and three more receivers.
The RF board employs an asymmetric structure based on a hybrid PTFE / FR4 substrate and is provided with a planar antenna which is hard to produce. RF board is costly since 80 percent of substrate materials are now monopolized by Rogers RO3003 ED G2 (Japanese companies use Panasonic R5515).
For special radar structures, the baseband board and the RF board are as usual separated by an aluminum-zinc alloy die-casting board whose edges are connected to the radar plastic housing via shockproof rubber in order to meet the waterproof and shockproof requirements of automotive standards as well as to avoid interference to the RF board.
The plastic cover on the antenna of automotive radar takes into account the microwave transmission effect. Vendors attach great importance to the thickness, material and shape of the plastic cover, which is part of the radar design. Generally speaking, they prefer materials with ultra-low dielectric coefficient and surprisingly low losses as well as resistance to dust, water and vibration to cater to automotive grade. Bosch used PEI in the early days, and later turned to PBT-GF30 provided by BASF, while Continental has adhered to PBT-GF30 invariably. Valeo and Aptiv replace expensive PBT with SPS for 24GHz radar, and they are studying how to apply it to 77GHz radar.
Chinese millimeter-wave radar vendors pay much more than foreign counterparts because of low chip procurement. The price major foreign vendors pay for each of MMIC, MCU and RF PCB is equivalent to 1/3 to 1/4 of that by Chinese ones, and that for analog products such as power management is 1/4 to 1/5 of Chinese peers'. However, the Chinese millimeter-wave radar cost will be cut substantially once the procurement goes up.
The threshold for access to MMIC is low, and the Chinese MMIC vendors embrace a rosy prospect. Foreign chips, especially made by Infineon, are expensive and unfriendly for Chinese vendors who have to select NXP. In this case, MMIC made in China is very popular.
The China-made forward 77GHz radar is led by Shenyang Cheng-Tech and Huayu Automotive Systems, and the 24GHz radar is largely offered by Wuhu Sensortech Intelligent Technology (WHST) and it has been heavily shipped to Hongqi cars.