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1.
C. Y. D. Sim 《国际射频与微波计算机辅助工程杂志》2012,22(2):243-247
A novel single probe‐fed circularly polarized (CP) microstrip antenna design for global positioning system application is proposed. To achieve good CP radiation at 1575 MHz, two circular slots of dissimilar sizes are embedded separately into the radiating element and the ground plane. This CP design possesses the advantages such as simple in structure, uncomplicated fine‐tuning technique, and ease in manufacturing tolerances. Parametric studies via simulation are carried out to comprehend the vital parameters that will affect the impedance matching and frequency of the CP radiation. Prototypes of the proposed antenna have been constructed and experimentally studied. The measured results show a 10‐dB bandwidth and 3‐dB axial ratio bandwidth of 2.28 and 0.89%, respectively. Furthermore, stable gain variation at around 3.6 dBic is also observed. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012. 相似文献
2.
A single probe‐fed square microstrip antenna with two pairs of asymmetric narrow slots loaded into the ground plane for circular polarization (CP) is studied. To allow a simple fine tuning CP mechanism, the method of loading an additional square slot into the center of the ground plane is introduced into this proposed antenna. By tuning the overall‐size of this center square slot, the CP frequency can be easily tuned with minor effects on the CP performances. Furthermore, good axial ratio (AR) value of around 0.5 is also measured at 1575 MHz, which is suitable for GPS operation. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE , 2013. 相似文献
3.
In this article, design and development of wideband circularly polarized (CP) rectangular dielectric resonator antenna (RDRA) is presented. To generate wideband CP in proposed antenna, different feeding mechanism have been studied. Three antenna configurations based on different feeding have been discussed using single and dual pair of microstrip lines aligned perpendicular to each other to generate orthogonal modes resulting in circular polarization. It has been claimed here that excitation of RHCP/LHCP field and its direction of radiation could be controlled using height of microstrip feed lines. Finally antenna configuration‐3 is fabricated and measured which shows 36.8% of input impedance bandwidth (3.48–5.05 GHz) and axial ratio bandwidth of 14.46% (3.67–4.24 GHz) in broadside direction (at Φ = 0°, θ = 0°). The final proposed structure exhibits consistent far‐field characteristics with average LHCP gain of 6.4 dB and almost stable radiation efficiency in entire operational frequency range. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:713–723, 2016. 相似文献
4.
A new meandered‐line inductor fed wideband circularly polarized rectangular dielectric resonator antenna (DRA) with partial ground plane has been developed in this work. Meandered‐line inductor feed and partial ground plane are used for generation of orthogonal modes, hence circular polarization (CP) in DRA. By controlling the length of meandered‐line inductor, three different CP DRA have been designed for different wireless applications such as Wi‐MAX and WLAN/ISM 2400 band. Distribution of electric field inside rectangular DRA shows that all three antenna having TE11δ mode. Finally, a lower frequency band application at 2.4 GHz (ISM) called here as Proposed Antenna, has been considered for fabrication. This designed antenna shows measured ?10 dB input impedance bandwidth of 20.67% and 3‐dB axial ratio bandwidth of 27.95% in broadside direction. All these three CP antennas (Antenna‐1 to Proposed Antenna) are showing stable gain and right hand circular polarization in broadside direction. 相似文献
5.
In this article, a new radiating stub microstrip feed has been investigated with asymmetrical ground plane for generation of circular polarization (CP) in a dielectric resonator antenna (DRA). Here, asymmetrical ground plane and 3 radiating stubs with microstrip feed line are used for generation of 2 different modes namely TE11δ and TE12δ in rectangular DRA. By using mode matching concepts, these modes are responsible for enhancing the impedance bandwidth (TE12δ ie, and ) and axial ratio (AR) bandwidth (TE11δ ie, and ) in proposed antenna. Designed antenna offers measured input impedance bandwidth (|S11| < ?10 dB) and AR bandwidth (AR < 3‐dB) of 44.78%, ranging from 4.6 to 6.9 GHz and 23.32%, ranging from 4.6 to 6.9 GHz, respectively. It has been observed that proposed antenna shows left‐handed CP fields in boresight direction with average gain of 3.15 dBic and radiation efficiency of 90.54%. Designed antenna is suitable for Wi‐MAX (3.3‐3.7 GHz) applications. 相似文献
6.
In this article, a hybrid microstrip fed dual‐cylindrical dielectric resonator antenna (dual‐CDRA) has been proposed for the sub‐6 GHz band application with a wide circular polarization band. The proposed hybrid microstrip feed cylindrical dielectric resonator antenna utilizes an S‐shaped microstrip feed line to excite fundamental HE11δ like mode and hybrid mode in dual‐CDRAs. The presented antenna structures are acting as monopole antenna separately with 48.75% (3.88‐6.38 GHz) bandwidth whereas both radiators called dual‐CDRAs enhances the bandwidth up to 93.06% (2.16‐5.92 GHz) in addition with an axial ratio bandwidth of 15.2% (3.52‐4.1 GHz). The proposed antenna is applicable for WiMAX (3.4‐3.69 GHz), and WLAN application of 802.11d and 8.02.11e IEEE standard. For validation of simulated results, an antenna prototype has been fabricated and experimentally verified. A good agreement between simulation and measured results are obtained. The simulation results have been carried out by using Ansys HFSS 14.0 version software. 相似文献
7.
The metamaterial elements and structures have been noticed for obtaining circular polarization (CP) while developing various procedures. In this paper, we have mentioned some of these cases and compared the metamaterial loads effect on antenna current distribution. We have classified them into four categories. The first case covers patch antenna based on composite right/left‐handed method, where the metamaterial has been used for changing the current distribution in the loop form. The second case has been achieved by radome and metasurface. In the third model, the interaction between feed and metamaterial load has been considered and the last case has been made by the metamaterial load with truncated structure. The metamaterial loading has been modeled based on Nicolson‐Ross or transmission/reflection techniques for extracting the permittivity and permeability. While the microstrip slot antennas are attractive for wider bandwidth, the truncated structure can change the current for achieving CP. Here, we have studied the antenna for wireless and WiMAX applications. 相似文献
8.
为了满足X频段机载雷达天线的指标要求,使得矩形平面天线与柱面共形,通过并联侧馈方式进行馈电。在微带共形阵天线的相关理论基础上,阵元采用介电常数2.2,厚度为0.5mm的介质基板。通过HFSS12对微带共形阵天线进行仿真设计并优化。实验结果表明,在X波段内实现了方位面的全向扫描,实测阻抗带宽为9.80-10.20GHz,最大增益可达10dB,全向辐射性能稳定,满足了指标要求。 相似文献
9.
The design of a simple ultrahigh frequency RFID (radio frequency identification) reader antenna that can operate within the North America RFID band (902–928 MHz) is studied. To generate circular polarization (CP) radiation in this band, a novel method of loading two narrow open‐ended slots (slits) into an eccentric annular slot patch is proposed. To allow optimum impedance matching with enhanced CP bandwidth, the radiating patch is loaded to an L‐shaped ground plane. From the experimental results, the proposed antenna can yield an impedance bandwidth (10‐dB return loss) between 650 MHz to 1125 MHz, while good CP bandwidth (3‐dB axial ratio, AR) from 901 MHz to 930 MHz is also attained. Furthermore, gain level and efficiency of more than 7.8 dBic and 90%, respectively, were also measured. By simply removing one of the slits, this proposed antenna can also be modified to operate within the China (840–846 MHz) and European (865–868 MHz) RFID band. 相似文献
10.
A broadband high‐gain circularly polarized (CP) microstrip antenna operating in X band is proposed. The circular polarization property is achieved by rotating four narrow band linearly polarized (LP) microstrip patch elements in sequence. Since the conventional series‐parallel feed network is not conducive to the miniaturization of the array, a corresponding simplified feed network is designed to realize the four‐way equal power division and sequential 90° phase shift. With this feed network, the impedance bandwidth (IBW) of the CP array is greatly improved compared with that of the LP element, while maintaining a miniaturized size. Then, parasitic patches are introduced to enhance the axial ratio bandwidth (ARBW). A prototype of this antenna is fabricated and tested. The size of proposed antenna is 0.93λ0 × 0.93λ0 × 0.017λ0 (λ0 denotes the space wavelength corresponding to the center frequency 10.4 GHz). The measured 10‐dB IBW and 3‐dB ARBW are 13.6% (9.8‐11.23 GHz), 11.2% (9.9‐11.07 GHz) respectively, and peak gain in the overlapping band is 9.8 dBi. 相似文献
11.
Neng‐Wu Liu Mei‐Jiao Sun Lei Zhu Zhi‐Hui Jia Lu‐Yang Ji Guang Fu Hui‐Li Zheng 《国际射频与微波计算机辅助工程杂志》2020,30(3)
A compact monopolar microstrip patch antenna (MPA) with enhanced‐bandwidth is proposed. In order to achieve the miniaturized patch, the zeroth‐order mode of the MPA instead of its higher‐order modes is employed at first by loading the shorting pin around the center of the patch. After that, a L‐shaped microstrip line with a shorting pin is introduced at the periphery of the patch radiator to excite an additional non‐radiative mode for bandwidth enhancement. In final, the proposed MPA is fabricated and measured. The results illustrate that the antenna generates an enhanced‐bandwidth of about 4.1% ranging from 2.39 to 2.49 GHz, which is significantly larger than that of the traditional MPA around 1%. Meanwhile, the dimensions of the radiating patch are obviously decreased down due to the employment of zeroth‐order mode, which are kept as small as about 0.17 λ0 × 0.22 λ0 × 0.026 λ0 (λ0 is the free‐space wavelength). 相似文献
12.
In this article, details of a dual band microstrip patch antenna (MPA) array feed for an offset reflector antenna is presented. The main objective of the proposed structure is to achieve low cross‐polarization at Φ = 90° plane in the reflector pattern. Low cross‐polar levels in the reflector pattern are achieved by illuminating the reflector with fields of the proposed dual band feed structure. A centered circular array as the dual band feed structure is proposed in which the central radiating element is a dual mode circular MPA operating at 6 GHz and the surrounding circular ring of eight circular MPA elements operating at 4 GHz in the dominant mode. The dual mode central antenna uses the concept of conjugate field matching for cross‐polarization reduction. TM21 mode is excited at an appropriate ratio with the TM11 mode to achieve the proper field matching at 6 GHz. The radius of the surrounding circular array is varied to obtain cross‐polarization better than ?30 dB at both the resonant frequencies. The offset reflector gain is found to be better than 37 dB with a 2.5 m parabolic reflector and F/D = 0.8 at both the operating frequencies. 相似文献
13.
M. S. Nishamol V. P. Sarin D. Tony C. K. Anandan P. Mohanan K. Vasudevan 《国际射频与微波计算机辅助工程杂志》2011,21(6):680-686
A single feed compact microstrip antenna achieving frequency and polarization diversity using a varactor is presented. A simple patch antenna with an X‐slot constitutes the fundamental structure. The frequency and polarization agility is realized by varying the reactance of an embedded varactor at the center of the X‐slot with respect to the biasing from 0 to 25 V. The prototype fabricated on a substrate of dielectric constant (εr) 4.4 and height (h) 1.6 mm is fed by a proximity feed fabricated using the same substrate. By controlling the bias voltage of the varactor, the polarization of the antenna can be switched between linear and circular polarization. Furthermore, the proposed antenna offers stable broadside radiation characteristics without any extra impedance matching circuit. The frequency and polarization diversities of this design could potentially improve the reliability of wireless communication systems. The details of the antenna are presented and discussed. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE , 2011. 相似文献
14.
A new compact square microstrip patch antenna is proposed using the optimization approach, namely, the genetic algorithm (GA). The antenna is designed at three different frequencies, 785 MHz., 1.57 GHz, and 2.46 GHz, for mobile communication, GPS, and Bluetooth applications, respectively. The simulations are carried out using IE3D from Zeland Software, which is based on the method of moments (MoM). The antenna consists of a probe‐fed truncated‐corner square patch with four inserted slits along the four diagonals and four angular grooves along the four edges of the patch. The proposed design has a reduced antenna size, as compared to the conventional microstrip antenna at a given operating frequency. The return loss, impedance, and axial‐ratio bandwidth are determined and compared with the conventional square‐patch antenna. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006. 相似文献
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16.
This article initially proposes a directly‐fed circular patch antenna with L‐shaped ground plane for Radio Frequency Identification (RFID) applications in the 900 MHz (902?928 MHz) ultrahigh frequency (UHF) band. To achieve circularly polarized (CP) radiation, two arc‐shaped notches are loaded into the main patch. To enhance the CP bandwidth so that the proposed antenna can also cover the UHF RFID band for Europe (866?869 MHz), a parasitic element is printed besides the main patch. Experimental measurements show that the 10‐dB return loss bandwidth of the proposed antenna was 30.95% (833?1138 MHz) and its corresponding 3‐dB axial ratio bandwidth was 8.95% (865?946 MHz). Good gain and radiation efficiency of more than 7 dBic and 90%, respectively, were also exhibited across the two desired UHF RFID bands. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:681–687, 2015. 相似文献
17.
Nemai Chandra Karmakar 《国际射频与微波计算机辅助工程杂志》2007,17(3):311-319
The resonant frequency of a circular patch antenna with and without circular cavity is measured. The patch miniaturization in the presence of the cavity is proved. Different methods of reducing resonant frequencies and broadening bandwidth without significantly reducing antenna gain are presented. Capacitively loaded patch and slits on the patch stimulate the patch at lower frequencies and multiple resonances, thus help miniaturization. Finally ferrite loading on the feed probe further increases the bandwidth without significantly reducing the antenna gain. The method is much more improved than that for a resistive loaded patch and a deformed patch. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007. 相似文献
18.
A broadband circularly polarized (CP) circular patch antenna with an L‐shaped ground plane and parasitic element is studied. The use of this L‐shaped ground is to achieve short probe feed connection to the circular patch, while maintaining a certain height between the circular patch and ground plane, so that good impedance matching and bandwidth enhancement can be attained. To achieve CP radiation, two notches are initially loaded diagonally into the circular patch, and to further enhance the CP bandwidth, a novel technique of loading a small size moon‐shaped parasitic element into the notched circular patch is proposed. By doing so, the CP bandwidth of proposed antenna can be tremendously increased by approximately 10%. The experimental results show that the proposed CP antenna can yield impedance bandwidth and CP bandwidth of 835–1150 MHz and 839–968 MHz, respectively, with good gain level of 7.6 dBic. Therefore, this proposed wideband CP antenna can be used for UHF (ultrahigh frequency) RFID (radio frequency identification) reader antenna that operates within the universal RFID bands (840 ? 960 MHz). © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:387–395, 2016 相似文献
19.
T. Sedgeechongaraluye‐Yekan M. Naser‐Moghadasi R. A. Sadeghzadeh 《国际射频与微波计算机辅助工程杂志》2015,25(9):825-833
In this article, a wide‐band circularly polarized slot antenna array with reconfigurable feed‐network for WiMAX, C‐Band, and ITU‐R applications is proposed. Different novel methods are used in proposed array to improve antenna features such as impedance matching, 3 dB axial‐ratio bandwidth (ARBW), gain, and destructive coupling effects. Miniaturized dual‐feed square slot antenna, with one attached L‐shaped strip and a pair of T‐shaped strip at ground surface for improving impedance matching and circular polarization (CP) purity, is presented. For further enhancement of CP attributes, reconfigurable sequentially rotated feed network is utilized to obtain wider 3 dB ARBW. Furthermore reconfigurable property of network gives controlling Right and Left handed CPs, respectively. Finally, a special form of Electromagnetic Band gap structure is employed on top layer of substrate that provides high isolation between radiating elements and array feed network to enhance overall performance of antenna. The measured results depict 3 dB ARBW from 4.6 to 7.2 GHz, impedance bandwidth from 3.3 to 8.8 GHz for VWSR<2, and peak gain of 10 dBi at 6 GHz. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:825–833, 2015. 相似文献
20.
In this article, frequency tuning and circularly polarized concentric circular microstrip antenna is investigated. The proposed antenna consist of varactor diode for frequency tuning and branch line coupler (BLC) feed network to achieve the circular polarization (RHCP/LHCP). By changing the varactor diode capacitance between 12.33 pF (0 V) to 1.30 pF (15 V) attain the frequency tuning (2.34‐2.68 GHz). The right hand circular polarization (RHCP) and left hand circular polarizations (LHCP) are realized in the antenna through BLC feed network output ports. The impedance bandwidth (2.05‐3.13 GHz) of BLC feed network is well‐matched with the circular microstrip antenna frequency tunable bandwidth. The proposed antenna is fabricated, and simulated results are verified using the mathematical modeling and experimental verification. 相似文献