调皮哥推荐必读资料：为什么要从传统的 24 GHz跨越到最先进的77GHz雷达（中英文翻译）

1.前言

原文：Radar technology has been in existence for nearly a century across a wide variety of applications, ranging from military to law enforcement to commercial. Interest in the use of radar has exploded in the last decade, especially in the automotive and industrial space.

译文：雷达技术已经存在了将近一个世纪，从军事领域到社会执法领域然后再到商业领域，应用范围十分广泛。在过去的十年里，人们对使用雷达的兴趣大幅提高，尤其是汽车和工业领域。

调皮哥笔记：雷达在社会执法领域的应用，如交通测速雷达、安防禁区等。

In the automotive space, primary radar applications can be broadly grouped into corner radars and front radars. Corner radars (at both the rear and front corners of the car) are typically short-range radar (SRR) sensors that handle the requirements of blind-spot detection (BSD), lane-change assist (LCA) and front/rear cross-traffic alert (F/RCTA), while front radars are typically mid- and long-range radars responsible for autonomous emergency braking (AEB) and adaptive cruise control (ACC). In the industrial space, the applications for radar include fluid and solid level sensing, traffic monitoring, robotics and more.

译文：在汽车领域，主要的雷达应用可以大致分为角雷达和前向雷达。转角雷达(在汽车的前后角)通常是短程雷达(SRR)传感器，可处理盲点检测(BSD)、变道辅助(LCA)和前后交叉交通警报(F/RCTA)等需求；而前向雷达则通常是负责自动紧急制动(AEB)和自适应巡航控制(ACC)的中远程雷达。在工业领域，雷达的应用包括流体和固体液位传感、交通监测、机器人等方面。

In this article, two frequencies, 24 GHz and 77 GHz, commonly used in these applications will be discussed. We will discuss the shift in the industry toward 77 GHz radar and the various benefits you can achieve. Texas Instruments has a family of highly integrated radar sensors that enables customers to leverage the benefits of the 77 GHz frequency band for radar applications in both the automotive and industrial markets

译文：在本文中，我们将会讨论这些应用中常用的两个频率，即24 GHz 和 77 GHz，以及行业向 77 GHz 雷达跨越可以带来的各种好处。德州仪器 (TI) 拥有一系列高度集成的雷达传感器，使客户能够在汽车和工业市场的雷达应用中利用 77 GHz 频段的优势。

2. 24 GHz 和 77 GHz 频段

Let’s start by reviewing the relevant frequency bands of interest (see Figure 1). The 24 GHz band includes an industrial, scientific and medical (ISM) band from 24.0 GHz to 24.25 GHz, which is often called the narrowband (NB), having a bandwidth of 250 MHz.This band is unlicensed and can be used as per provisions in [1, 2, 3]. The 24 GHz band also includes an ultrawide band (UWB), which is 5 GHz wide. For short-range radar, the 24 GHz NB and UWB bands have been in use in legacy automotive sensors. For simple applications like basic BSD, you can use NB ISM, but in most cases, including ultrashort-range radar applications, the need for highrange resolution dictates the use of the UWB band.

译文：让我们先回顾一下相关的感兴趣频段，如图1所示。24 GHz频段包括24.0 GHz到24.25 GHz，主要属于工业、科学和医疗(ISM)频段，通常被称为窄带(NB)，带宽B为250 MHz。

调皮哥笔记：“感兴趣”这个词语经常在各种文献资料中看见，意思是我们需要了解、关注、追寻，或者是需要探索的内容，外国人喜欢用“感兴趣（ interest）”一词，而中国人很少使用这种词汇。两种文化的差异，使得翻译资料的人员需要注意，把一些概念解释清楚，易于科研技术人员的阅读和理解。

（图1 24GHz 和77GHz频带）

该频段未经许可不能擅自使用，用户可按照资料 [1, 2, 3] 中的规定使用，24 GHz 频段还包括一个 5 GHz 宽的超宽带 (UWB)。对于短程雷达，24 GHz NB 和 UWB 频段已用于传统汽车传感器，对于基本 BSD（盲点检测） 等简单应用，可以使用 NB ISM，但在大多数情况下（包括超短程雷达应用），对高分辨率的需求决定了需要使用 UWB 频段。

调皮哥笔记：“高分辨率的需求决定了需要使用 UWB 频段”，这句话的意思是雷达的发射信号带宽决定了雷达的距离分辨率（公式可自行推导，调皮哥之前写的文章里面有推导过程）。因此需要高分辨需求，则必然需要使用大带宽、超带宽（UWB）。

Due to spectrum regulations and standards developed by the European Telecommunications Standards Institute (ETSI) and the Federal Communications Commission (FCC), the UWB band will be phased out soon [4, 5, 6, 7]. The 24 GHz UWB band will not be available after January 1, 2022known as the “sunset date,” both in Europe and the U.S.; only the narrowband ISM band will be available long term. This lack of wide bandwidth in the 24 GHz band, coupled with the need for higher performance in emerging radar applications, makes 24 GHz unattractive for new radar implementations.

译文：根据欧洲电信标准协会 (ETSI) 和联邦通信委员会 (FCC) 制定的频谱法规和标准，UWB 频段将很快被淘汰 [4, 5, 6, 7]。24 GHz 的UWB 频段将在 2022 年 1 月 1 日（称为“日落日”）后在欧洲和美国变为不可用，只有窄带 ISM 频段可以长期可用。由于24 GHz 频段缺乏宽带宽，再加上新兴雷达应用对更高性能的需求，使得 24 GHz对新的雷达实施方案毫无吸引力。

This is especially true considering the significant interest in the automotive industry for advanced applications like automated parking and 360-degree view. Looking at 77 GHz, there is a 76-77 GHz band available for vehicular long-range radar applications. This band has the benefit of high allowed equivalent isotropic radiated power (EIRP), which enables front long-range radar applications like adaptive cruise control. This band is also available in Japan [9], as well as in Europe[7] for fixed transport infrastructure radar systems to enable applications such as vehicle counting, traffic jam or accident detection, vehicle speed measurement and vehicle detection for traffic light activation.

The 77-81 GHz shortrange radar (SRR) band is a new entrant; this band has recently gained significant traction both from a worldwide regulation perspective, as well as industry adoption. The availability of wide sweep bandwidth up to 4 GHz in this band makes it attractive for applications requiring high range resolution. Moving forward, most 24 GHz automotive radar sensors will likely shift to the 77 GHz band

译文：考虑到汽车行业对自动泊车以及 360 度全景等高级应用的浓厚“兴趣”，从24GHz跨越到77GHz是十分正确的。从 77 GHz 来看，有一个 76-77 GHz 频段可用于车载远程雷达应用，该频段具有高允许的等效全向辐射功率 (EIRP) 优势，可实现自适应巡航控制等前置远程雷达应用。该频段在日本 [9] 和欧洲 [7] 也可用于固定交通基础设施雷达系统，以实现诸如车辆计数、交通拥堵或事故检测、车速测量和交通灯激活车辆检测等应用。

77-81 GHz 短程雷达 (SRR) 频段是一个“新进入者（刚被行业内人员进行研究和使用）”，从全球监管角度以及行业采用雷达的方向上来看，该频段最近都获得了巨大的关注。该频段中高达 4 GHz 的宽扫描带宽的可用性使其对于需要高距离分辨率的应用具有吸引力，因此可以展望，在未来大多数 24 GHz 汽车雷达传感器都极有可能会转向 77 GHz 频段。

The 75-85 GHz band is available for industrial fluid and solid level sensing applications [8], making 77 GHz radar sensors attractive for industrial applications. Let’s discuss the various benefits of using the 77 GHz frequency band in both automotive and industrial applications.

译文：75-85 GHz频段可用于工业流体和固体液位传感应用[8]，这使得77 GHz雷达传感器在工业应用上更具有吸引力，接下来让我们一起讨论一下在汽车和工业应用中使用77 GHz频段的各种好处。

3. 距离高分辨率和距离高精度

One of the key benefits of 77 GHz is the wide bandwidth available in that band. Compared to the 200 MHz ISM band, which is available at 24 GHz, there is significantly higher bandwidth available at 77 GHz. Specifically, the 77-81 GHz SRR band offers up to 4 GHz of sweep bandwidth. The availability of wide bandwidth significantly improves range resolution and accuracy. The range resolution of a radar sensor signifies its ability to separate two closely spaced objects, whereas the range accuracy signifies the accuracy in measuring the distance of a single object. Since range resolution and accuracy are inversely proportional to the sweep bandwidth, a 77 GHz radar sensor can achieve 20x better performance in range resolution and accuracy compared to 24 GHz radar. The achievable range resolution is 4cm (versus 75cm for 24 GHz radar).

译文：77 GHz的主要优点之一是与24 GHz下可用的200 MHz ISM频段相比，该波段的带宽很宽。77 GHz下可用的带宽明显更高，具体地，77-81 GHz SRR频段提供高达4 GHz的扫描带宽。宽带宽的可用性显著提高了距离分辨率和精度，雷达传感器的距离分辨率指的是能够将两个距离较近的物体分开的能力，而距离精度指的是测量单个物体距离的准确性。由于距离分辨率和精度与扫描带宽成反比，77GHz雷达传感器在距离分辨率和精度方面可以比24GHz雷达提高20倍，可实现的距离分辨率为4cm(相对于24 GHz雷达的75cm)。

文章来源：Moving from legacy 24 GHz tostate-of-the-art 77 GHz radar.pdf