Design of a Tag Antenna for UHF RFID Food Systems

Abstract

This paper proposes a tag antenna for radio frequency identification (RFID) food system. The RFID tag antenna is designed and fabricated based on the rectangular loop concept used in the UHF band (Korean and Japanese standards, 916.7 923.5 MHz). The proposed tag antenna is composed of a radiation patch, sensor tag chip, temperature sensor, oscillator, and battery. We conjugated matching between the tag antenna and the sensor tag using a U-shaped stub. Details of the proposed tag antenna design and the simulated and measured results are presented and discussed.Key Words: Food Systems, Semi-Active Sensor, UHF RFID. . INTRODUCTIONRadio frequency identification (RFID) now finds applications in many areas, including logistics tracing, traffic control, environmental surveillance, and medical and grocery tracking. The RFID system consists of a reader and a tag, and the UHF RFID system operates at the bands of North America (902 928 MHz), Europe (865 867 MHz), Japan (916.7 923.5 MHz), and Korea (917 923.5 MHz). RFID is classified into passive and active types according to the method used to obtain the energy source of the electric wave. The passive type obtains the transmission energy from the electric wave received from the reader. The active type obtains the transmission energy from the battery. The passive tag has a semi-permanent life, no battery, is inexpensive, and is suitable for short range communication. On the other hand, the active tag can be used for long range communication because the battery is built into the tag.However, the high price and the battery lifetime currently restrict the use of RFID. Several papers have been published on RFID antennas for both passive and active tags [1][2][3][4][5][6][7][8][9][10][11][12][13], such as a shorted micro-strip patch antenna that uses an inductively coupled feed for the UHF RFID tag [2], miniaturization of a rectangular loop antenna using a meander line for RFID tags [3], RFID tag antennas that use an inductively coupling feed [4], a flexible planar RFID tag antenna with low performance degradation from nearby target objects [8], a broadband UHF RFID tag antenna with a rectangular-loop feed and additional patches [9], a planar loop tag antenna with bandwidth enhancement for the UHF RF-ID system [10], a long range UHF RFID tag with a rectangular metallic cavity structure [11], and a design for an integrated loop coupler and loop antenna for RFID applications [12]. The active RFID can provide long range data transmission because it uses different fields (the environmental monitoring, military, and health care). The requi-

Long-Range UHF RFID Tag for Automotive License Plate

“…ISO 18000-7 specifies the active 433 MHz RFID system, and ISO 18000-6 specifies the 860 to 960 MHz UHF band. The 2.45 GHz band is specified by ISO 18000-4 [ 4 , 5 , 6 , 7 ]. Recently, ISO 18000-6C and 6D were added to the ISO standard, and 18000-61~18000-64 were specified in the ISO 18000-6:2013 document [ 8 ].…”

Radiation Beam Pattern Control of UHF RFID Tag Antenna Design for Automotive License Plates

“…Another advantage of using active tags is transmitting signals over relatively long distances, 100 m and above. The complexity, power source, and larger memories make active tags more expensive than passive tags [4][5][6][7][8].…”

“…The ISO 18000 series standard is an international standard that states the air interface for the different RFID frequencies in use around the globe as outlined below. The band below 135 kHz is defined by ISO 18000-2, 13.56 MHz is defined by ISO 18000-3 for the HF band, ISO 18000-7 for the 433 MHz band, ISO 18000-6 for the 840-960 MHz UHF band, and the 2.45 GHz band is specified by ISO 18000-4 [4][5][6][7]. Recently, ISO 18000-6C and -6D were added to the ISO standard and 18000-61~18000-64 were specified in the ISO 18000-6:2013 document [9].…”