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Showing papers on "Front-to-back ratio published in 2016"


Journal ArticleDOI
TL;DR: In this article, the authors proposed a dual-band microstrip patch array antenna for WLAN and WiMAX applications, which is obtained by employing two parasitic patches gap coupled to the driven elements of a single layer proximity fed 2 × 1 microstrip array configuration.
Abstract: Design and development of a novel dual-band microstrip patch array antenna suitable for WLAN and WiMAX applications are presented. The proposed array configuration is obtained by employing two parasitic patches gap coupled to the driven elements of a single layer proximity fed 2 × 1 microstrip patch array configuration. The proposed dual-band array has the advantages of enhanced bandwidth and gain. The feed patches are excited by proximity feeding method and the parasitic patches are excited by gap-coupling. This microstrip patch array provides resonances at two frequencies of 2.584 GHz (2.412-2.629 GHz) and 3.508 GHz (3.469-3.541 GHz). This novel configuration has a measured gain of 8.51 dBi and 5.8 dBi in lower and upper bands with an impedance bandwidth of 8.16% and 2.05% respectively. Additionally, to enhance the front to back ratio at the upper resonant frequency, a metal plate is placed at the back side of the array antenna. This modified proximity fed gap coupled array provides directional radiation patterns with improved gains. Re-configurability in the form of beam steering is obtained in the modified array configuration by varying the air gap between the ground plane and metal plate. The simulated results are in good agreement with the experimental ones.

26 citations


Journal ArticleDOI
TL;DR: In this paper, the authors exploit the spherical mode expansion to miniaturize a transverse electromagnetic (TEM) horn antenna and achieve good frequency and time domain performances by modifying the loop's geometry.
Abstract: The spherical mode expansion is exploited to miniaturize a transverse electromagnetic (TEM) horn antenna and achieve good frequency and time domain performances. To adjust the radiated powers of fundamental transverse electric and transverse magnetic modes, the combined loop and TEM horn antenna is engineered. The constructive combination of the two modes below the horn’s turn-on frequency miniaturizes the antenna and improves its gain. The magnitude and phase tuning of the desired modes is achieved by modifying the loop’s geometry. The spherical modal spectrum at higher frequencies is also studied and the antenna’s geometry is further modified to maintain constructive interference between the higher order spherical modes. A prototype with electrical size of $0.188~\lambda ~\times0.145\lambda ~\times0.087\lambda $ (length $\times $ width $\times $ height) at the turn-on frequency is fabricated over a ground plane. Over three times lower turn-on frequency is obtained compared to a conventional TEM horn with up to 9 dB improvement in the realized gain at the low end and better radiation characteristics over more than 5:1 bandwidth (from 0.87 to 4.5 GHz). Unidirectional operation with front to back ratio >9 dB and excellent time-domain performance with fidelity factor >95% over wide field of view are also demonstrated.

23 citations


Journal ArticleDOI
TL;DR: In this article, a substrate integrated waveguide (SIW) cavity backed slot antenna with low back radiation is proposed, which exhibits broadband characteristics due to the meta-mushroom structure and a bowtie slot on the SIW.
Abstract: A novel substrate integrated waveguide (SIW) cavity backed slot antenna with low back radiation is proposed in this study. This newly proposed meta-mushroom antenna uses a SIW cavity to decrease the back radiation. It is fed by the SIW cavity backed slot and radiates by meta-mushroom structure. This antenna exhibits broadband characteristics due to the meta-mushroom structure and a bow-tie slot on the SIW. The back radiation of the proposed antenna is considerably diminished by the SIW cavity located at the back side maintaining high gain performance. After all, its front-to-back ratio is increased and maintained over 19.2 dB in the operating frequency band, 4.5–5.6 GHz. Full-wave simulation and experiments results of the proposed antenna are demonstrated.

18 citations


Patent
04 Mar 2016
TL;DR: In this paper, a Vivaldi antenna having an upper conductor and a lower conductor is described, where each conductor includes elliptical loading section or sections disposed around its flare section to enhance performance of the antenna by improving the front to back ratio as well as other factors for the antenna.
Abstract: A Vivaldi antenna having an upper conductor and a lower conductor. A signal connector feed is attached to a rear end of the conductors while each conductor includes a curved flare section extending forwardly for the reception or transmission of the signal. Each conductor includes elliptical loading section or sections disposed around its flare section to enhance performance of the antenna by improving the front to back ratio as well as other factors for the antenna.

3 citations


Proceedings ArticleDOI
01 Jul 2016
TL;DR: In this article, a compact semi-ring slot Yagi-like directive antenna is presented with a measured bandwidth of 374 MHz which covers from 3.522 to 3.896 GHz.
Abstract: A compact semi-ring slot Yagi-like directive antenna is presented. The center frequency of operation is 3.6 GHz targeting the WiMAX band. It has a measured bandwidth of 374 MHz which covers from 3.522–3.896 GHz. A very simple and compact reflector element having a size of 14 × 9.5 mm2 is introduced. A high front-to-back ratio (FBR) of 12.6 dB is achieved without using any complex back-lobe reduction technique or additional reflector layer which is usually used to get high FBR in slot antennas. The design has directivity of 4.2 dB. The proposed antenna is very compact having an overall size of 40 × 40 × 0.8 mm2.

2 citations


Patent
27 Apr 2016
TL;DR: In this paper, a double-polarization base station antenna with U-shaped reflecting plate and a discrete radiating element is presented, which is equipped with the parting strip between two adjacent radiating elements and buckled for the center line symmetry setting of reflecting plate.
Abstract: The utility model discloses a high front -to -back ratio double polarization base station antenna, include the reflecting plate of U -shaped, the reflecting plate is followed its central line and is equipped with the discrete radiating element who arranges of a plurality of periodicity, is equipped with the parting strip between two adjacent radiating element, be equipped with the S type respectively between the both sides of parting strip and the lateral wall of reflecting plate and buckle, and two S types is buckled for the center line symmetry setting of reflecting plate. The utility model discloses a double polarization base station antenna low cost, easily production and maintenance, the radiation front -to -back ratio can improve more than the 30dB under the condition that does not increase the reflecting plate size, simultaneously, the arm width of radiation arm is outwards crescent, and the frequency band of antenna has been extended in effective exhibition, makes the antenna have good gain characteristic.

1 citations


Proceedings ArticleDOI
01 Dec 2016
TL;DR: In this article, a split ring resonator (SRR) loaded dual band, twisted slotted waveguide antenna is presented, where two SRR structures are placed on both sides of the radiating slot to achieve dual band characteristics.
Abstract: This paper presents a split ring resonator (SRR) loaded dual band, twisted slotted waveguide antenna Two SRR structures are placed on both sides of the radiating slot to achieve dual band characteristics It has been shown that the placing of SRR structures, on the transverse plane, improves the gain and front to back ratio

1 citations


01 Jan 2016
TL;DR: In this paper, a modified antenna array achieving less mutual coupling by reshaping ground plane and using tuned Elongated Mushroom Electromagnetic Band Gap (EM-EBG) was proposed.
Abstract: Radiation surface wave (surface current) on ground plane has a destructive effect on the characteristics of antennas which benefits from a common ground plane, especially Cavity Backed Slot (CBS) antennas. Surface current increases mutual coupling in an antenna array. This in turn causes unwanted characteristics in array applications. The main goal of this work is to design a new modified antenna array achieving less mutual coupling by reshaping ground plane and using tuned Elongated Mushroom Electromagnetic Band Gap (EM-EBG). Moreover, in this study, we focus on the influence of changing depth of EM-EBG holes. In this regard, four different designs for CBS antenna arrays are investigated. The results reveals that by using two new methods, namely stepped ground plane and tuned EMEBG, mutual coupling will be decreased by more than 9 dB. Decrement of mutual coupling improve radiation characteristic of array such as Front to Back Ratio (FBR) by 8 dB. The effectiveness of our design is confirmed by experimental results.

Patent
20 Jan 2016
TL;DR: In this paper, a U-shaped reflecting plate, where a plurality of periodic discretely-arranged radiation units are arranged along the center line of the reflecting plate and an isolation bar is arranged between every two adjacent radiation units, each S-shaped bend is formed between each side of the isolation bar and the corresponding side wall of reflecting plate.
Abstract: The invention discloses a high front-to-back ratio dual polarization base station antenna. The high front-to-back ratio dual polarization base station antenna comprises a U-shaped reflecting plate, wherein a plurality of periodic discretely-arranged radiation units are arranged along the center line of the reflecting plate; an isolation bar is arranged between every two adjacent radiation units; each S-shaped bend is formed between each side of the isolation bar and the corresponding side wall of the reflecting plate; and the two S-shaped bends are symmetrically arranged relative to the center line of the reflecting plate. The high front-to-back ratio dual polarization base station antenna is low in cost and is easy for production and maintenance, and can improve the radiation front-to-back ratio to greater than 30dB without increasing the size of the reflecting plate. And at the same time, the arm width of a radiation arm gradually increases outwardly and the frequency band of the antenna is effectively broadened so that the antenna is high in gain characteristic.