In theory, Log-Periodic Antenna (LPA) is a linearly polarized antenna with frequency independent properties on the input impedance and gain patterns. Owing to these characteristics, LPA has gained research interests a...In theory, Log-Periodic Antenna (LPA) is a linearly polarized antenna with frequency independent properties on the input impedance and gain patterns. Owing to these characteristics, LPA has gained research interests and been employed for many wideband applications. A Printed Log-Periodic Dipole Antenna (PLPDA) with multiple notched bands is proposed for Ultra-WideBand (UWB) applications. An antenna with the notched frequencies of 1.03 GHz, 1.28 GHz, 1.72 GHz, 2.24 GHz and 2.51 GHz is designed, fabricated, and measured. An antenna model was established on the substrate of FR4 and feed by a stripline. The simulation results show that the antenna can achieve an impendence wide bandwidth from 0.89 to 2.58 GHz with return loss less than -10 dB and exhibit stable antenna gain. Furthermore, the measurement result is better consistent with simulation result.展开更多
A log-periodic antenna can provide directivity and gain when operating in a wide band.The log-periodic antenna is used in many applications where wide bandwidth is required along with direct and medium gain.This resea...A log-periodic antenna can provide directivity and gain when operating in a wide band.The log-periodic antenna is used in many applications where wide bandwidth is required along with direct and medium gain.This research implements a sequential approach to the design and simulation of the performance of a printed log-periodic dipole antenna(LPDA)capable of operating in the 1800 MHz frequency range.The advantage of this antenna is the compactness and easy integration into planar circuits suitable for applications requiring wide bandwidth and high gain.The dimension of the designed antenna was originally calculated taking high frequency as 1885 MHz and low frequency as 1805 MHz,then modeled using HFSS-13 electromagnetic simulation to determine the effect of substrate dielectric properties on dipole width and length for element optimization.The design was verified by creating and measuring S11 and radiation diagrams.The designed antenna has a total gain of 7.9 dB and a wide bandwidth.展开更多
This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in differe...This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a MSA are investigated numerically. The partial ground plane removal reduces the backlobe radiation of the MSA by suppressing the surface wave diffraction from the edges of the antenna ground plane. For further improving the front-to-back (F/B) ratio of the MSA, a new soft-surface configuration consisting of an array of stand-up split ring resonators (SRRs) are placed on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 9.7 dB has been achieved experimentally for our proposed MSA.展开更多
文摘In theory, Log-Periodic Antenna (LPA) is a linearly polarized antenna with frequency independent properties on the input impedance and gain patterns. Owing to these characteristics, LPA has gained research interests and been employed for many wideband applications. A Printed Log-Periodic Dipole Antenna (PLPDA) with multiple notched bands is proposed for Ultra-WideBand (UWB) applications. An antenna with the notched frequencies of 1.03 GHz, 1.28 GHz, 1.72 GHz, 2.24 GHz and 2.51 GHz is designed, fabricated, and measured. An antenna model was established on the substrate of FR4 and feed by a stripline. The simulation results show that the antenna can achieve an impendence wide bandwidth from 0.89 to 2.58 GHz with return loss less than -10 dB and exhibit stable antenna gain. Furthermore, the measurement result is better consistent with simulation result.
文摘A log-periodic antenna can provide directivity and gain when operating in a wide band.The log-periodic antenna is used in many applications where wide bandwidth is required along with direct and medium gain.This research implements a sequential approach to the design and simulation of the performance of a printed log-periodic dipole antenna(LPDA)capable of operating in the 1800 MHz frequency range.The advantage of this antenna is the compactness and easy integration into planar circuits suitable for applications requiring wide bandwidth and high gain.The dimension of the designed antenna was originally calculated taking high frequency as 1885 MHz and low frequency as 1805 MHz,then modeled using HFSS-13 electromagnetic simulation to determine the effect of substrate dielectric properties on dipole width and length for element optimization.The design was verified by creating and measuring S11 and radiation diagrams.The designed antenna has a total gain of 7.9 dB and a wide bandwidth.
文摘This study presents a new, simple method for reducing the back-lobe radiation of a microstrip antenna (MSA) by a partially removed ground plane of the antenna. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a MSA are investigated numerically. The partial ground plane removal reduces the backlobe radiation of the MSA by suppressing the surface wave diffraction from the edges of the antenna ground plane. For further improving the front-to-back (F/B) ratio of the MSA, a new soft-surface configuration consisting of an array of stand-up split ring resonators (SRRs) are placed on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 9.7 dB has been achieved experimentally for our proposed MSA.
