Chien-Wen Chiu

Inductively Coupled Loop Antenna Design for UHF RFID on-Body Applications

This paper presents a one-wavelength loop antenna fed by an inductively coupled loop for on-body applications. An equivalent circuit for the inductively coupled loop antenna is proposed to synthesize the antenna system with a microchip. The designed tag is printed on a PVC substrate and placed close to a four-layer stratifled elliptical cylinder human model. The card-type tag measures 85:5 £ 54 £ 0:76mm 3 and is suitable for use on a student ID card for a broad range of applications. The impedance bandwidth of the inductively coupled loop tag antenna is 60MHz (880{940MHz, 6.6%), which covers the operating UHF bands in U.S. and Taiwan. The measured reading distance ranges from 2.7 to 5.7 meters when placed at difierent positions on the chest of a human body in the open site.

CPW-fed dual rectangular ceramic dielectric resonator antennas through inductively coupled slots

CPW-fed dual rectangular ceramic dielectric resonator antennas through inductively coupled slots have been studied by experiment. A better bandwidth is achieved if these compare with only single dielectric resonator as antennas. Also, these antennas can be easily do the input impedance matching using several parameters like adjusting the length of inductive slots, the space between dielectric resonators, and the offset distance of DR center to the center of end inductive slots.

CPW-fed rectangular ceramic dielectric resonator antennas with high profile

This work presents the performance of rectangular ceramic dielectric resonator antennas with high profile coupled by an open-ended CPW. Dielectric resonators with dimensions of 18.66 mm /spl times/18.66 mm /spl times/ 6 mm and relative dielectric coefficient of 36 are used to apply to the frequency band of 2.5 GHz. The measured results show the high profile DRA have lower frequency and better bandwidth than those of DRA with low profile.

An internal hepta-band printed loop antenna for laptop computer

This paper presents a simple printed-loop antenna with wideband characteristic. The rectangular loop pattern generates four resonant modes. A U-shape tuning element printed on the back side of the circuit board can be used to adjust the resonant modes to cover GSM850/GSM900/DCS/PCS/UMTS/WLAN2.4 and WiMAX2.7 bands. Simulation was performed here by HFSS to optimally design the antenna and the practical structure was also fabricated to verify the simulation results. The measured antenna parameters are presented to validate the proposed antenna.

Compact printed quadrifilar helix antenna for universal RFID hand-held reader

This paper presents a compact printed quadrifilar helix antenna (PQHA) for portable UHF RFID reader applications. The circularly polarized PQHA is fed by a feeding network with quadrature-phase and equal amplitude output signals. The quadrature-phase feeding network is composed of a 180° power splitter and two wideband quadrature hybrid couplers implemented by lumped-element circuits. The miniaturized antenna is a one-wavelength resonance type and can preserve high antenna gain. Moreover, the bandwidths of impedance and axial ratio cover the global UHF RFID band (860–960 MHz). The measured impedance bandwidth is about 34.1% and the axial ratio bandwidth covers 700–1,000 MHz. The measured maximum gain is 5.8 dBic and the 3-dB beamwidth is 168°. The height of the entire system is only 79 mm, the radius is 35 mm, and the FR4 substrate for the feeding network is only 80 × 80 × 1.6 mm3. The proposed antenna is suitable for handheld UHF RFID reader applications.

An inductively-feed loop tag antenna close to a human body for UHF RFID applications

This paper presents a UHF RFID loop tag antenna for on-body applications. The proposed one-wavelength loop fed by an inductively coupled loop is printed on a PVC card and put close to a human body. The proximity effect due to the human body is considered in the design stage. The human model is composed of a four-layer stratified elliptical cylinder. The designed tag was constructed and experiment was performed to measure reading ranges. The measured reading range achieves about 5 meters when the tag is pasted on the chest of a human body.

An internal quad-band printed antenna for PDA phone

This paper presents a quad-band inverted-F antenna with an overall size of 46 × 12 × 0.8 mm3 and with electromagnetic compatible propriety. The proposed antenna has an inverted-L element combined with a meander-line branch to excite two resonant modes. By using a matching element, the bandwidth can be broadened to cover GSM850/GSM900/DCS/PCS bands. Simulation was performed here by HFSS to optimally design the antenna and the practical structure was also fabricated to verify the simulation results. The measured antenna parameters are presented to validate the proposed antenna.