A μ negative metamaterial using spiral resonator (SR) with an electromagnetically coupled (EMC) feeding system is proposed as a novel antenna structure. The proposed antenna is designed and fabricated on a FR4 dielec...A μ negative metamaterial using spiral resonator (SR) with an electromagnetically coupled (EMC) feeding system is proposed as a novel antenna structure. The proposed antenna is designed and fabricated on a FR4 dielectric substrate with a thickness of 1.6 mm and relative permittivity of 4.0 to achieve its radiation characteristic. The antenna is operated at frequency 2.4 GHz. To improve the antenna gain, a matching circuit is inserted into the feed line. The µnegative metamaterial is achieved by using a spiral resonator with spiral numbers N = 3, 5, 7, and 10. It is found that the negative imaginary part tends to shift leftward as the value of N increases. The simulation result of the proposed antenna structure with spiral number N = 3, strip width w = 3.1 mm, and gap width s = 0.5 mm provides the best performance with S11 = -15 dB, VSWR < 2 bandwidth of 30 MHz and gain of –0.5 dB at frequency of 2.43 GHz. The proposed antenna with matching circuit provides the antenna gain of 2.21 dB, which is better than that without the matching circuit. The dimensions of the proposed antenna are reduced by 53% compared with those of the conventional patch. Both the simulation and measurement results of the radiation characteristics of the proposed antenna show good agreement.展开更多
The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The computational formulae for calculating the radiation fields of the airborne spiral anten...The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The computational formulae for calculating the radiation fields of the airborne spiral antennas are developed by using geometrical theory of diffraction (GTD). The calculated results are in good agreement with the experimental ones.展开更多
The design and optimization of a self-complementary two-arm Archimedean spiral antenna backed by an absorptive cavity were presented. Parametric studies on the proposed antenna structure were carried out by using CST ...The design and optimization of a self-complementary two-arm Archimedean spiral antenna backed by an absorptive cavity were presented. Parametric studies on the proposed antenna structure were carried out by using CST MWS. Simulation results show that the proper choice of spiral turns and cavity depth can miniaturize the dimensions of the cavity-backed spiral antenna presented here. According to simulation results, prototype antennas operating in the 6 12 GHz band are fabricated and the dimension of the proposed cavity-backed spiral antenna is 22 mm (diameter)×15 mm (height). The performance of the proposed antenna was measured and compared with the simulation results. It is shown that the experimental results are consistent with the theoretical predictions and the suggested antenna is good enough to adapt for various wideband applications.展开更多
In this paper, we compare a dual-band, square spiral microstrip patch antenna constructed from Multi-Walled Carbon Nanotubes (MWCNT) ink for wearable application simulated by Computer Simulation Technology Microwave S...In this paper, we compare a dual-band, square spiral microstrip patch antenna constructed from Multi-Walled Carbon Nanotubes (MWCNT) ink for wearable application simulated by Computer Simulation Technology Microwave Studio (CST MWS) by our work simulated by Advanced Design System (ADS) electromagnetic simulator using the same material characterization. The reflection coefficient is –12 dB at 1.2276 GHz for MWCNT and –13 dB at 1.25 GHz for the copper simulated by CST MWS and reflection coefficient is –12.235 dB at 1.234 GHz for MWCNT and –18.36 dB at 1.243 GHz for the copper simulated by ADS and the reflection coefficient is –27dB at 2.47 GHz for MWCNT and –13 dB at 2.53 GHz for the copper simulated by CST MWS and the reflection coefficient is –26.08 dB at 2.48 GHz for MWCNT and –17.031 dB at 2.47 GHz for the copper simulated by ADS. We show the meandering of the surface current on the radiating in spiral patch. The antenna gain is found to be –12.5 dBi at 1.22 GHz for MWCNT and is found –12.05 dBi at 1.25 GHz at CST MWS and the antenna gain is found to be –11.85 dBi at 1.235 GHz for MWCNT and is found –12.25 dBi at 1.243 GHz at ADS and the antenna gain is found to be –4.25 dBi at 2.47 GHz for MWCNT and is found –4.01 dBi at 2.53 GHz at CST MWS and the antenna gain is found to be –4.23 dBi at 2.47 GHz for MWCNT and is found –4.88 dBi at 2.45 GHz at ADS. We show a close agreement in the results obtained by the two simulation software's CST MWS and ADS. The results are given for both MWCNT and Copper characterizations.展开更多
This paper proposes a quasi-static conformal mapping analysis to analytically evaluate the input resistance of Archimedean spiral antenna at its radiation region. The deviation from the original constructs of band the...This paper proposes a quasi-static conformal mapping analysis to analytically evaluate the input resistance of Archimedean spiral antenna at its radiation region. The deviation from the original constructs of band theory for two-wire spiral antennas leads to the concept of common slot-line mode radiation. The per-unit-length capacitance and the characteristic impedance of the quasi-TEM fundamental propagating mode in periodic coplanar waveguide (PCPW) structure are obtained in terms of spiral parameters including substrate properties. This formula enables little computational effort on the computation of input resistance at the radiation mode of balanced-excited two-arm Archimedean spiral antennas. The numerical simulation demonstrates the accuracy of derived formulas both in free space and when a dielectric layer is presented.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 μ negative metamaterial using spiral resonator (SR) with an electromagnetically coupled (EMC) feeding system is proposed as a novel antenna structure. The proposed antenna is designed and fabricated on a FR4 dielectric substrate with a thickness of 1.6 mm and relative permittivity of 4.0 to achieve its radiation characteristic. The antenna is operated at frequency 2.4 GHz. To improve the antenna gain, a matching circuit is inserted into the feed line. The µnegative metamaterial is achieved by using a spiral resonator with spiral numbers N = 3, 5, 7, and 10. It is found that the negative imaginary part tends to shift leftward as the value of N increases. The simulation result of the proposed antenna structure with spiral number N = 3, strip width w = 3.1 mm, and gap width s = 0.5 mm provides the best performance with S11 = -15 dB, VSWR < 2 bandwidth of 30 MHz and gain of –0.5 dB at frequency of 2.43 GHz. The proposed antenna with matching circuit provides the antenna gain of 2.21 dB, which is better than that without the matching circuit. The dimensions of the proposed antenna are reduced by 53% compared with those of the conventional patch. Both the simulation and measurement results of the radiation characteristics of the proposed antenna show good agreement.
文摘The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The computational formulae for calculating the radiation fields of the airborne spiral antennas are developed by using geometrical theory of diffraction (GTD). The calculated results are in good agreement with the experimental ones.
文摘The design and optimization of a self-complementary two-arm Archimedean spiral antenna backed by an absorptive cavity were presented. Parametric studies on the proposed antenna structure were carried out by using CST MWS. Simulation results show that the proper choice of spiral turns and cavity depth can miniaturize the dimensions of the cavity-backed spiral antenna presented here. According to simulation results, prototype antennas operating in the 6 12 GHz band are fabricated and the dimension of the proposed cavity-backed spiral antenna is 22 mm (diameter)×15 mm (height). The performance of the proposed antenna was measured and compared with the simulation results. It is shown that the experimental results are consistent with the theoretical predictions and the suggested antenna is good enough to adapt for various wideband applications.
文摘In this paper, we compare a dual-band, square spiral microstrip patch antenna constructed from Multi-Walled Carbon Nanotubes (MWCNT) ink for wearable application simulated by Computer Simulation Technology Microwave Studio (CST MWS) by our work simulated by Advanced Design System (ADS) electromagnetic simulator using the same material characterization. The reflection coefficient is –12 dB at 1.2276 GHz for MWCNT and –13 dB at 1.25 GHz for the copper simulated by CST MWS and reflection coefficient is –12.235 dB at 1.234 GHz for MWCNT and –18.36 dB at 1.243 GHz for the copper simulated by ADS and the reflection coefficient is –27dB at 2.47 GHz for MWCNT and –13 dB at 2.53 GHz for the copper simulated by CST MWS and the reflection coefficient is –26.08 dB at 2.48 GHz for MWCNT and –17.031 dB at 2.47 GHz for the copper simulated by ADS. We show the meandering of the surface current on the radiating in spiral patch. The antenna gain is found to be –12.5 dBi at 1.22 GHz for MWCNT and is found –12.05 dBi at 1.25 GHz at CST MWS and the antenna gain is found to be –11.85 dBi at 1.235 GHz for MWCNT and is found –12.25 dBi at 1.243 GHz at ADS and the antenna gain is found to be –4.25 dBi at 2.47 GHz for MWCNT and is found –4.01 dBi at 2.53 GHz at CST MWS and the antenna gain is found to be –4.23 dBi at 2.47 GHz for MWCNT and is found –4.88 dBi at 2.45 GHz at ADS. We show a close agreement in the results obtained by the two simulation software's CST MWS and ADS. The results are given for both MWCNT and Copper characterizations.
文摘This paper proposes a quasi-static conformal mapping analysis to analytically evaluate the input resistance of Archimedean spiral antenna at its radiation region. The deviation from the original constructs of band theory for two-wire spiral antennas leads to the concept of common slot-line mode radiation. The per-unit-length capacitance and the characteristic impedance of the quasi-TEM fundamental propagating mode in periodic coplanar waveguide (PCPW) structure are obtained in terms of spiral parameters including substrate properties. This formula enables little computational effort on the computation of input resistance at the radiation mode of balanced-excited two-arm Archimedean spiral antennas. The numerical simulation demonstrates the accuracy of derived formulas both in free space and when a dielectric layer is presented.
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.
