RF Circuit Board - Millimeter Wave Radar PCB

In the field of autonomous driving in automobiles, there have always been two routes: laser radar and millimeter wave radar. Entering 2024, millimeter wave radar is rapidly applying this technology to achieve its own intelligent upgrade. Currently, almost every vehicle with autonomous driving function on the road is equipped with laser radar or millimeter wave radar. Millimeter wave radar still requires other sensors to compensate for its limitations.

The design scope of automotive radar goes beyond the traditional 2-18GHz military radar system and typically operates in the 24GHz and 76-81GHz frequency bands. These frequency bands are further divided into the following other frequency bands.

The 24GHz frequency band includes two frequency bands

24.05-24.25GHz (UNB): This frequency band includes the Industrial, Scientific, and Medical (ISM) band from 24.05-24.25GHz, also known as ultra narrowband UNB. This frequency band has been widely used in traditional automotive millimeter wave radar. It supports short distance functions such as blind spot detection, short distance warning, approaching obstacle warning, and lane change warning system.

21.65-26.65GHz (UWB): The total bandwidth of UWB is 5GHz, which is mainly used in traditional radar. Due to its better resolution than UNB, UWB is commonly used for short-range applications similar to UNB.

At present, the 24GHz UWB frequency band has been gradually phased out, paving the way for a wider range of 77GHz frequency bands for automotive applications.

The 77GHz radar frequency band includes a portion of the total bandwidth of 5GHz, ranging from 76-81GHz. The Long Range Radar (LRR) occupies a total bandwidth of 600MHz in the 76-77GHz range. Medium range radar (MRR) operates within a 600MHz bandwidth of 77-81GHz, while sweep frequency short-range radar (SRR) can access a total 4GHz bandwidth of 77-81GHz.

The automotive radar operating at 77GHz provides higher resolution for remote object detection and has sufficient bandwidth to support high resolution even at close range. For example, a short-range radar with a 1GHz bandwidth of 76-77GHz can provide a resolution of about 0.5m, while another short-range radar with a 4GHz bandwidth of 77-81GHz can provide a resolution of about 0.1m. The following table compares the bandwidth range, resolution, and interoperability of various frequency bands.

The frequency conversion of automotive millimeter wave radar to the entire 76-81GHz frequency band will generate an internationally unified frequency band that can support LRR and SRR applications. In addition, the availability of millimeter wave radar frequency bands for dedicated vehicles will reduce the potential for interference with other radar systems. This allocation enables global radar suppliers and OEMs to leverage the economies of scale brought about by frequency band coordination. It is expected that this will further reduce costs and promote the widespread application of radar in automobiles.

Millimeter Wave Radar PCB

RO3003G2 high-frequency PCB material can be used for millimeter wave radar PCB.

Rogers RO3003G2 high-frequency ceramic filled PTFE laminated board is an extension of Rogers' industry-leading RO3003 PCB. Based on industry feedback, the RO3003G2 PCB board is specifically designed to meet the next-generation requirements of millimeter wave automotive radar circuit board Radar PCB application.

RO3003G2 PCB board combines optimized resin and filler content to provide lower insertion loss, making it ideal for use in ADAS systems such as adaptive cruise control, forward collision warning, and active braking or lane change assistance.