What’s Inside an RFID Card?
Whether it’s for access control or time tracking, RFID Cards are a convenient and efficient way to keep track of information. However, like any new technology, it comes with a few recurring costs that you should be aware of.
One of the most common concerns with RFID cards is their security. While they do put out radio signals, they are designed to only work within close proximity of a reader.
Chip
The microchip in an RFID card contains a memory for information and an antenna to transmit the data. The chip can either be passive, powered by the signal sent to it by a scanner, or active, using its own power source. It can store up to 100 megabytes of information.
RFID can save time and effort when it comes to stock-taking RFID Card and inventory, as well as for tracking shipments. It is also used in ID badges that can be programmed to let certain people through security doors and block others from doing so. The technology is also able to communicate with satellites, which can locate and monitor the location of an item or person with an RFID tag attached.
One of the most interesting applications for RFID technology is in self checkout at supermarkets, where customers can simply wave their card over a reader to pay. This allows the customer to get out of the line quicker and make fewer trips to the cashier.
Another use for RFID is in electronic ticketing on buses, trains and subways. Instead of having to wait at the ticket booth while the employee tabulates your fares, you can just wave your bus or train pass over an RFID reader and the amount is deducted from your bank account automatically. These types of passes are also being used on highway toll passcards and on public transit in some cities.
Antenna
The RFID antenna is the hands and feet of the system, responsible for transmitting and receiving radio frequency signals that interact with tags. It is also a critical factor in the read range of an RFID system. The type of RFID tag and reader antenna you choose depends on your specific needs, such as read zone coverage, mounting requirements, and the frequency band used.
The RF identification antenna receives the energized signal from the reader and broadcasts it as radio waves to RFID tags. It is the most crucial component of an RFID system, and there are a variety of options available. It is important to choose an antenna that operates in the same frequency band as your tags. This ensures that the signal is strong enough to be detected.
Antennas vary in size and gain (in dB), which is the ratio of the amplitude of the signal to the noise level. The higher the dB, the more pronounced the increase in the signal strength. However, it’s important to note that the decibel scale is logarithmic, meaning that a large amount of gain could result in a significant decrease in signal strength.
In addition, the RFID antenna must be capable of operating in extreme conditions. This includes high temperatures, humidity, and impact. It should also be able to work on metal surfaces and be waterproof.
Substrate
The substrate of the RFID tag is what holds the other components of the tag together. It’s usually made of a plastic polymer such as PVC, Polyethylene Terephtalate (PET), Polycarbonate (PC), or Acrylonitrile Butadiene Styrene (ABS). It must also be able to withstand the various environmental conditions through which it will pass during its lifecycle.
The chip in an RFID card consists of integrated circuits (ICs) that store data and perform certain tasks. These ICs may be read-only, write-once, read-many (WORM), or read/write. The ICs are powered by the electromagnetic energy transmitted from an RFID reader. The RFID antenna is a thin metallic coil that picks up the mifare desfire radio signals from the reader. The ICs then process these signals and transmit the information to the reader.
In some applications, the ICs are combined with sensors to perform more complex functions. For example, a sensor can help predict the actual expiration date of a carton of milk. This can be different from the printed expiration date because of the conditions under which it is stored. In such cases, it is important to characterization of the RF transparent material on which the sensing component is mounted to ensure accurate results. The characterization should be performed over a wide temperature range and humidity range to avoid false alarms. The characterization should also be done using a full-wave 3D simulator such as Ansys HFSS v11.1. The input impedance of the sensing component is conjugate matched to that of the RFID chip’s resonant frequency at 915 MHz.
Power Supply
The power supply used in RFID cards converts energy from an external source into a form that can be delivered to the system’s components. The power supply also regulates voltage, current, and frequency. The power supply may be a separate piece of equipment, or it can be built into the load appliance, such as a computer or consumer electronics device.
Modern PC computers use a switch-mode power supply to convert AC power from the mains to several DC voltage output rails. Linear power supplies were once common, but the switch-mode designs are more cost, weight, and efficiency efficient. They are smaller than linear power supplies and can deliver a variety of voltages at widely varying current draw requirements.
An uninterruptible power supply (UPS) takes its input from the power grid or energy storage devices like batteries and fuel cells. It then charges a battery that provides instantaneous backup power to the load, protecting against unexpected interruptions in the flow of electricity.
Some PSUs are designed to control how much power is drawn from the output rails, and a common feature is the ability to limit current through an internal controller. In addition, some power supplies come with sleeved cables that make wiring easier and reduce the effect of their heat on airflow. Power supplies are categorized according to their physical design, with bench-type models being a stand-alone desktop unit, open frame versions having only partial mechanical enclosures and rack mount power supplies being designed for secure installation in standard electronic equipment racks.