RFID (Radio Frequency Identification) technology has become a vital tool in modern vehicle access control, offering automated solutions for secure, efficient, and reliable entry management. Whether it’s for a corporate parking facility, gated communities, or high-security zones like airports and seaports, RFID technology ensures only authorized vehicles can gain access, providing safety and efficiency from the moment a vehicle approaches a gate. This article explains how RFID technology works in vehicle access control and highlights why it’s the go-to solution for many organizations today.
What is RFID?
RFID is a wireless technology that uses electromagnetic fields to identify and track objects, such as vehicles, by reading data stored on a tag attached to the object. Every RFID system consists of three main components:
- Reader: A device that sends and receives radio waves.
- Antenna: A part of the reader that transmits radio signals to tags and receives responses.
- Tag: A transponder attached to the vehicle, which responds to the reader’s signals by transmitting data.
RFID tags can be either passive, semi-active, or active, depending on whether they have an internal power source and how they communicate with the reader.
RFID for vehicle access control
For gate access control, RFID can be used to automatically identify vehicles and drivers. The ability to allow or deny access based on a vehicle having an RFID tag is a valuable way to provide a perimeter or building an enhanced level of security. These systems keep out unauthorized vehicles that would otherwise take up space and prevents individuals from entering a secure building or lot. RFID technology is therefore perfect to use for secured vehicle access applications, such as highly secured vehicle access at airports, seaports and mines. It’s also relevant for fast and convenient vehicle access to car parks, gated communities, staff parking areas, and campuses.
But how does RFID work?
RFID Reader and Antenna
The principle of all RFID systems are basically the same: a reader uses an antenna to transmit and receive radio signals. It’s possible that the antenna is integrated into the reader or that one or more antennas are externally connected to the reader. Once an RFID tag gets in range of the reader, it will be activated and starts returning a radio signal.
The antenna transmits radio signals to the tag for multiple functions:
- To energize tags without battery (passive tags).
- To send instructions to the tag, for example to perform a secure authentication or to request specific information from the tag of the driver.
- To receive radio signals from the tag, for example the tag identification number.
Different antenna designs can be distinguished. The antenna design will determine the detection area. For vehicle identification systems a long range directional antenna is very useful. The long read range offers a convenient and seamless experience. The directional antenna enables the system to identify only vehicles in a specific lane and prevent cross-reads from vehicles in a separate nearby lane. If you want to know more about different antenna designs and which you should use, we would like to advise you.
RFID Tags
RFID tags are often placed on vehicles like cars, trucks and buses to automatically identify them and grant secure access to the premises. The tag contains an identification number that can be transmitted back to the reader. It may also contain other relevant information, security codes, keys, etc.
There are three types of RFID tags:
- Passive tags: tags without power source (no batteries). They are powered by the radio signals transmitted by the reader antenna. This guarantees a long lifetime. These tags use radio signal modulation to transmit information back to the reader. The read range relies on:
– at which range the tags can still be powered
– at which range the reader still receives the tag’s signal.
- Semi-active tags: tags with an internal power source (battery), but with no active transmitter. The tag does not draw power from the reader. It uses backscatter reflection techniques to transmit information back to the reader. This allows for a long read range without the high current consumption.
- Active tags: tag with an active transmitter and with their own power source (battery). These tags can actively transmit their signal to the reader. This allows for a long read range, but typically will have a limited lifetime compared to passive and semi-active tags.
RFID tags are available in different shapes, such as ISO cards, stickers, buttons, etc. Note that the function is identical independent from its shape. You may choose a tag shape that best fits your application. Nedap offers an extensive tag portfolio with passive and semi-active RFID tags. For automatic vehicle identification systems, Nedap recommends to choose a semi-active or passive windshield tag that supports a long read range, because this ensures a fast, secure and convenient operation.
For a deeper look into the different types of RFID tags, check out our semi-active RFID solutions and our passive UHF RFID solutions.
RFID Frequencies
RFID tags and readers have to be tuned to the same frequency in order to communicate. There are different RFID frequencies for public use:
- Low frequency (LF): 120 – 125 kHz: Older (less popular) proximity technology based upon inductive electromagnetic coupling.
- High frequency (HF): 13.56 MHz: Contactless smartcard technology for short range and high security applications.
- Ultra-high frequency (UHF): 800 – 900 MHz: UHF technology enables low-cost passive tags with long read range.
- Microwave: 2.45 GHz: long-range identification in combination with semi-active tags.
Understanding the different frequencies with its specific characteristics at which RFID systems operate will help you to choose the right Automatic Vehicle Identification solution for your application.
Nedap’s advanced long-range RFID identification portfolio
Nedap specializes in automatic vehicle and driver identification, offering a highly refined portfolio of long-range RFID solutions. With decades of expertise in RFID technology, we have developed innovative solutions that provide high performance and reliability, even in the most demanding environments. Our long-range RFID systems, combined with License Plate Recognition (LPR) technology, are trusted worldwide across a wide range of industries. As pioneers in the field, we have built an extensive global track record of successful vehicle identification installations, offering secure and efficient access control solutions tailored to diverse industry needs.
Customer stories where Nedap’s RFID solutions were chosen for automatic vehicle identification:
Curious how our RFID solutions can help in your access control application? We would like to get in touch with you.
