Published in Microwave Journal on September 12, 2024.
Ultra-wideband (UWB) technology is increasingly being deployed in the automotive sector for a variety of reasons. One common application is to use the technology to surmount the vulnerabilities of RFID-enabled key fobs, which can easily be hacked and allow vehicles to be stolen. It is also being considered as a radar technology to ensure children are not left behind in the back seat.
AUTOMOTIVE ENTRY SYSTEMS
The 1982 Renault Fuego was the first model to use a remote key fob to unlock the car doors. Although the growth of this approach was initially slow, it accelerated in the 1990s. By 1995, around a third of vehicles made that year had the feature, with the penetration rate exceeding 50 percent in 2000.
In 1993, the Chevrolet Corvette was the first to use a passive entry system. In this system, an enabled fob would send out low frequency (LF) signals to unlock the car doors when it was near the vehicle. By 2014, penetration of passive entry systems reached 20 percent and this has now grown to 50 percent in 2024, with essentially all vehicles now being fitted with either remote or passive entry systems. Figure 1 shows data from TechInsights on the market share of remote and passive keyless entry systems.
Early passive entry systems were proprietary systems based on the ISM band before being replaced by the Bluetooth standard. The 2017 Tesla Model 3 was the first model to feature a Bluetooth Low Energy (BLE)-based entry system. The fob in this system used a Texas Instruments TMS37F128 controller chip. Replacing the earlier LF solution, BLE has become the communication standard for passive entry systems. Another technology being deployed in automotive entry systems includes near-field communication (NFC). The first model fitted with an NFC entry system was the 2016 Mercedes-Benz E-Class. Here, an enabled key card or smartphone handset is placed over an NFC reader on the vehicle to unlock the doors. Tesla models also come with NFC cards for use in valet parking.
Digital Key
Both NFC and BLE have now become the standard communication protocols for the Car Connectivity Consortium (CCC). These protocols were defined in its second and third digital key releases in April 2020 and July 2021, respectively. The purpose of the CCC is to develop and standardize entry systems for vehicles to add convenience to families and fleets sharing identical vehicles and enable new services. Members of the CCC include many original equipment manufacturers (OEMs), automotive Tier 1 integrators, mobile OEMs and semiconductor suppliers, including Infineon, NXP and STMicroelectronics.
These new services include car-sharing and remote delivery, among others. Enabling the new services is the digital key. The digital key dispenses with the need for mechanical blade keys that have been the cornerstone of the automotive sector since the 1950s, when they were first used to start engines. With such virtual “keys,” the same vehicle can be used by different drivers without the costly need for service centers to hold different keys. This technology can provide many benefits. Cars-for-hire companies stand to gain with lower operating costs and a delivery can be made to a vehicle instead of a customer who could be away from home. These digital keys can be exchanged via an app on a smartphone.
Standardization enables interoperability between different suppliers and OEMs in the automotive and mobile sectors. It also ensures the security of the resulting systems. In addition, it raises competition between suppliers to make the digital key concept affordable and bring about widespread adoption.
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