Compact Loop Antenna for Near-Field and Far-Field Uhf Rfid Applications

Abstract

A novel type of radio frequency identification (RFID) reader antenna is proposed for mobile ultra-high frequency (UHF) RFID device. By folded-dipole loop structure with parasitic element, a small antenna size of 31 * 31 * 1.6 mm 3 is achieved. The antenna with different parasitic element size can work on different UHF RFID bands. The antenna prototype is fabricated and the measured bandwidth is around 13.5 MHz (915.5-929 MHz), which covers the China RFID Band (920-925 MHz). The measured reading distance achieves 65 mm with the near-field RFID tag and 1.17 m with the far-field tag. The measurement agrees well with simulated result and shows that antenna is desirable for both near-field and far-field UHF RFID applications.

“Energy evaporation”: The new concept of indoor systems for WPT and EH embedded into the floor

“…Each unit-cell is composed by a 5.8 GHz microstrip coaxial fed antenna surrounded by a 13.56 MHz coil connected to a HF tag. Similar approaches of co-located HF and UHF antennas are proposed in [4], [5], with the goal of enhancing RFID tags capabilities. The HF part of the system is devoted to localization purposes exploiting the same principle of [6], while the RF patch antennas are connected to a power grid and, when activated by the HF system, radiate power to harvest the localized devices.…”

An Electrically Small 3-D Folded Grounded Loop Antenna for Omnidirectional Connectivity

“…From the technologies convergence in IoT, an essential functionality based on corresponding underlying enabling technologies is the wireless connectivity of the devices, especially in the category of short-range wireless which will include the majority of interconnected devices. Antennas and antenna arrays are very important for efficient link budgets in a variety of application segments within this general area, whether they are intended for RFID and related applications [8,9], Near Field Communications (NFC), Bluetooth Low Energy (BLE), and other enabling technologies and applications [10], even unrelated to data transfer, such as RF Energy Harvesting [11][12][13] and near-field wireless charging [14].…”

Design of High Gain Microstrip Patch Reader Array Antenna with Parasitic Elements for UHF RFID Application

“…The gain performance of the antenna can be increased by using array configuration and adding the parasitic elements. The paper presented in [12] proposed a compact loop antenna for UHF RFID applications. A folded-dipole antenna with parasitic elements are designed by using FR-4 substrate and produced gain of 4.4 dBi.…”

“…The practical antenna measurement setup Theoretically, Ground Reflection (Two-Ray) propagation model defined the path loss (PL) versus the distance between the Tx and Rx[12], as formula shown in Equation(1). PL = 32.44 + [20 log d] + [20 log f] -GT -GR + [Tother losses]…”