A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 9...A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 900 MHz achieves a uniform near magnetic field distribution inside the loop. A novel method is proposed to evaluate the performance of the coplanar waveguide （CPW） to coplanar stripline （CPS） transition, which is used as a balun for the feeding network in this paper. This loop antenna has a 70 MHz operating bandwidth and 12 cm maximum reading range when the output power is 24 dBm, which is suitable for most near field radio frequency identification （RFID） applications.展开更多
A highly compact chipless tag based on Frequency coding technique using Spiral Resonators is proposed in this paper.Spirals are well known metamaterial structures and thus capable of sharp resonance,and hence Spiral R...A highly compact chipless tag based on Frequency coding technique using Spiral Resonators is proposed in this paper.Spirals are well known metamaterial structures and thus capable of sharp resonance,and hence Spiral Resonators can serve as a good candidate for RF Identity Tags.The bit capacity of the proposed tag is 10 bits per sqcm.The prototype of the tag is fabricated on a low-cost substrate of dielectric constant 4.4 and loss tangent 0.02.The overall dimension of tag is 15.4 x 3 x 1.6mm3.Two methods for reading the tags are also discussed in this paper.Scope for bit enhancement is also provided.展开更多
文摘A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 900 MHz achieves a uniform near magnetic field distribution inside the loop. A novel method is proposed to evaluate the performance of the coplanar waveguide （CPW） to coplanar stripline （CPS） transition, which is used as a balun for the feeding network in this paper. This loop antenna has a 70 MHz operating bandwidth and 12 cm maximum reading range when the output power is 24 dBm, which is suitable for most near field radio frequency identification （RFID） applications.
文摘A highly compact chipless tag based on Frequency coding technique using Spiral Resonators is proposed in this paper.Spirals are well known metamaterial structures and thus capable of sharp resonance,and hence Spiral Resonators can serve as a good candidate for RF Identity Tags.The bit capacity of the proposed tag is 10 bits per sqcm.The prototype of the tag is fabricated on a low-cost substrate of dielectric constant 4.4 and loss tangent 0.02.The overall dimension of tag is 15.4 x 3 x 1.6mm3.Two methods for reading the tags are also discussed in this paper.Scope for bit enhancement is also provided.
