UHF RFID antenna and RFID tag Purchase knowledge

RFID uses radio waves for the transmission of information and the generation and reception of radio waves is done through an antenna. For RFID systems, the antenna is a crucial part, which is closely related to the performance of the system. For example, in a warehouse management project, the cost of an RFID antenna is less than 1% of the overall cost. However, if in order to single-mindedly reduce costs or other reasons leading to selection errors, the choice of poor performance RFID antenna, in the process of layout RFID antenna will be prone to read instability, leakage, serial reading, read failure and other problems. In this case, not only will the cost not be reduced, but will increase several times. Therefore, RFID antennas need to be taken into account when deploying RFID systems.

RFID Antenna Purchase Guide

A、Polarization method

1、line polarization antenna

Electromagnetic wave propagation completely in a plane of signal propagation direction (vertical or horizontal), when the direction of the tag is known and fixed, RFID antenna and RFID tag polarization match (vertical corresponds to vertical or horizontal corresponds to horizontal), when the best reading rate can be obtained.

2、Circular polarization antenna

When the angle between the polarization plane of the electric wave and the earth's normal plane varies from 0-360° periodically, that is, the electric field changes in size and direction with time, and the trajectory of the end of the electric field vector is projected as a circle in the plane perpendicular to the direction of propagation, it is circularly polarized.

Gain	A comprehensive measure of the energy conversion and directional characteristics of an antenna, defined as the product of the directional coefficient and the antenna efficiency, the higher the antenna directional coefficient, the higher the gain coefficient.
Azimuth	A measure of the antenna's ability to radiate capacity in the desired direction.
Main flap width	The main flap width is a physical measure of the extent of the antenna's maximum radiation area.
Polarisation loss	When the polarisation direction of the transmitting antenna is not the same as that of the receiving antenna, polarisation loss is usually incurred during reception

B、Antenna type

High performance PCB material antenna: widely used in handheld terminals, small reading and writing devices, can provide 1-5dBi gain.

Panel antennas: Widely used for people, vehicle and asset management, they can provide 5-15dBi gain.

High performance slit antenna: Widely used for personnel, vehicle and asset management, it can provide 5-10dBi gain.

Near field asset management antenna: Widely used in self-checkout counters, smart cabinets, shelves, can provide 2-5dBi gain.

Ceramic dielectric antenna: widely used in handheld terminals, small reading and writing devices, can provide 1-5dBi gain.

Special application antennas: suitable for vehicle antennas, sports timing antennas, handheld antennas, etc., which can provide 5-10dBi gain.

RFID Tag Purchase Guide

The RIFD tag is also known as the radio frequency tag, transponder, data carrier; the reader is also known as the readout device, scanner, read head, communicator, read-write (depending on whether the electronic tag can rewrite data wirelessly). The electronic label and the reader realize the space (no contact) coupling of the radio frequency signal through the coupling element; in the coupling channel, according to the timing sequence relationship, realize the energy transmission and data exchange.

A、Classification of UHF chips

From the point of view of the product form of the chip: common UHF chip has two major forms: bare chip (Wafer) and package chip, Wafer wafer cost is relatively low, can directly use inverted packaging, COB, COF; and package chip has QFN, SOT, CSP, etc., is in the wafer based on the secondary packaging, can be directly done as Chip parts with PCB, FPC or ceramic antenna for welding. FPC or ceramic antenna for welding, mainly used for special electronic tags.

From the point of view of product function: can be divided into ordinary UHF chip, high security encryption UHF chip and with sensor UHF chip these three categories. At present, the main UHF chip manufacturers are: Impinj, NXP, Allien, EM, Kiloway, Hdect, Fudan Micro, Quanray, etc.

B、RFID tags common type

Battery Distinguish	Passive RFID tags, Active RFID tags, Semi Active tags.
Frequency Distinguish	Low Frequency (125KHz and 134KHz), High Frequency (13.56MHz), Ultra High Frequency(840-960MHz), Microwave Frequency (2.45-5.8GHz)
Encapsulated Process Distinguish	Label, Hangtag, PVC card, ABS, PC, Molding, woven, textile, silicone, etc.
Functional Distinguish	Normal paper tags, Tamper proof tags, RFID on metal tags, Anti-liquid tags, Anti-freeze tags, High Temperature RFID tags, LED light tags, etc.
Application Distinguish	Airline baggage tags, Anti-counterfeit source tags, RFID Garment hangtags, RFID Tyre tags, Car windshields Labels, Medical Ampoule tags, etc.

C、UHF anti-metal tag type

RFID flexible an-metal label, PCB/Ceramics an-metal tags, Plastic an-metal tags, Card type anti-metal tags

Item	RFID flexible an-metal label	PCB/Ceramics an-metal tags	Plastic an-metal tags	Card type anti-metal tags
Printable	Printable by Zebra, Sato, Postek,etc.	Laser printing	Laser printing	Jet Printing and printing
Data personalization	Yes	Yes	Yes	Yes
Temperature Endurance	Bad	Good	Good	Good
Waterproofness	Bad	Good	Good	Good
Crashworthiness	Bad	Good	Good	Good
Stability	Short	Good	Good	Good
Reading Performance	Good	Good	Good	Good
Thcikness	Less than 2mm	Big than 2mm	Big than 2mm	Less than 2mm
Workability	Good	Normal	Bad	Excellent

D、UHF chip data comparison