Long Term Evolution-Advanced (LTE-A) system is operated with cellular technology based on frequency reuse. Due to the co-channel interference between cells, one cell’s performance is decided by not only its own configurations but also other cell’s settings. Therefore, joint optimization of antenna parameters in LTE-A cellular networks is the key to maximizing coverage and capacity. This can be achieved by setting the antenna parameters such as azimuth orientations and tilts to the optimal values. Nevertheless, the large number of cell parameters and the interdependencies between these parameters make it difficult and time-consuming to optimize a cellular network. In practice, the joint setting of the parameters of all cells with irregular layout and coverage areas becomes an important and challenging task.
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The Square ring shaped DGS as shown in the Figure 2 is been embedded with square MSA. The S11 parameter for the proposed antennas is calculated and the reflection coefficient of the antennas is obtained as shown in Figure 3. From the figure we can say that antenna-1 to antenna-4 is resonating with larger reflection coefficient of -18.93dB at 1.6875GHz to - 33.45dB at 5.5750GHz with impedance bandwidth as shown in the Table 1. Which is much larger than that obtained for conventional square MSA.
ABSTRACT: An inset fed rectangular patch antenna is designed to operate at 2.4 GHz using an FR-4 substrate of height h=1.6mm. Initially the ground plane dimensions are kept as 6h+L and 6h+W (short edge) ; Where L is length of patch and W is width of patch. It is found to have a low gain. To improve the gain, ground plane dimensions length and width are varied in multiples of Length (L) and Width (W) respectively. For double ground (2L, 2W) case, a gain of 2.6494dB is observed. A further improved gain of 3.0524dB is achieved by using triple ground (3L, 3W).The other parameters like VSWR, Return Loss and directivity are also improved by increasing ground plane dimensions .The antennae are fabricated and tested using VNA E5071C.
As for the Chapter 3, it will be covered on the antenna properties. The properties are on the basic antenna parameters. It is important to recognize the parameter of the antenna before designing the antenna itself. In addition, this chapter will be explained more on the feed technique of the antenna.
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In this paper, a low profile microstrip patch antenna is proposed. Unlike the usual method of placing the patch antenna on top of a ground plane, the patch is placed along side a small rectangular ground co planar to it. With the insertion of the slots into the patch, the proposed antenna can provide a large bandwidth with the same dimensions and suitable radiation characteristics. The thickness of the substrate is used approximately 1.6 mm and FR-4 lossy substrate material has been used. The size of the ground and their relative position are optimized to achieve a wide bandwidth. Structure of this antenna has been created by CST Microwave Studio Software and antenna parameters have been calculated using Matlab.
In this paper, a slim antenna was designed for the UWB application with a band of 839 MHz around 8.8 GHz. The antenna parameters are very compliant for this ap- plication. The bandwidth was improved with a tolerable degradation in some of antenna parameters. The designed antenna presents very significant values of gain and ra- diation efficiency and could be a very compliant solution for the applications that need gain and directivity such locating and tracking application (anti-collision vehicle radar or imaging radar). The most important application of the ultarwideband is the data transmission using spread spectrum allowing high data speed without inter- fering with conventional narrowband and carrier wave used in the same frequency band. The designed antenna can be used in different applications and it is then a suc- ceeded trade-off that respects the FCC UWB require- ments.
The designed linear array (8 elements) of M-shaped Vivaldi antenna is shown in Fig. 2. The gap between elements of array is kept at 10 mm. The antenna is fed with same signal parameters. The designed array antenna is investigated in term of antenna parameters. The antenna is then fabricated using an FR-4 substrate having dielectric constant of 4.4 and height of 1 mm. Return Loss, VSWR, and radiation pattern are tested in the laboratory after the fabrication of the prototype. During testing process in the laboratory BNC power divider which has 50 ohm nominal input impedance is used to insure that each element of the antenna gets the same signal power and same signal parameters. The measurements are conducted using Agilent Vector Network Analyzer (VNA) in open air conditions. For pattern measurement, the proposed antenna is ﬁxed on a positioner or turntable. The distance between the proposed antenna and probe antenna is adjusted to 8 meters for the purpose of far-ﬁeld pattern measurements.
Abstract—In this paper, a compact reconﬁgurable monopole antenna is proposed working at three diﬀerent frequencies depending upon the condition of the optical switch. The proposed reconﬁgurable antenna in the state of ON switch has resonant frequencies of 2.45 GHz and 5.4 GHz covering the band of 1.8–2.7 GHz (Wi-Fi) and 5.26–5.99 GHz (WLAN) respectively. The same antenna during OFF state of switch operates only at 3 GHz covering the band of 2.49–3.84 GHz. The proposed multiband reconﬁgurable antenna is designed and fabricated on an FR-4 substrate having relative permittivity of 4.4, loss tangent of 0.02 and thickness of 1.6 mm. The antenna is fabricated and tested in the laboratory to validate the simulated results. A good agreement between the simulated and measured results is obtained in term of radiation pattern and return loss. The performance of the reconﬁgurable antenna under both states of switch is examined on the basis of the antenna parameters such as return loss, radiation pattern and gain.
also provide low profiles, conformity to surfaces and direct integration with microwave circuitry. Consequently, microstrip patch antennas are used widely in antenna arrays. Additionally, the planar structure of a microstrip antenna permits the microstrip antenna to be conformed to a variety of surfaces having different shapes. Microstrip antennas can be designed to produce a wide variety of patterns and polarizations, depending on the mode excited and the particular shape of the radiating element used. This results in the microstrip antenna being applicable to many military and commercial devices, such as use on aircraft or space antennas. There is an increasing demand for the use of microstrip antennas in wireless communication due to their inherently low back radiation, ease of conformity and high gain as compared to wire antennas. The goal of this thesis is to study how the performance of the antenna depends on various parameters of the V-shaped microstrip patch antenna. This is a simulation based study. First, the antenna is designed at 2.4 GHz. Ansoft HFSS software tool is used for the design and simulation of the antenna. Then, the antenna parameters are varied to study the effect of variation of the antenna parameters on the antenna performance. Later, the bandwidth of the designed antenna is increased by increasing the thickness of the substrate.
ABSTRACT: In this research paper, a compact microstrip patch antenna had been design and analyzed. The proposed antenna get the required impedance bandwidth is 77.85%. The design antenna has resonant frequency of 2.2GHz.The bandwidth enhanced by changing parameters of rectangular microstrip patch antenna. The variation made in the design structure antenna is cut different slot on patch and simulate the result of design structure. The proposed antenna is used for band (2.057GHz to 4.679GHz) suitable for wireless communication. A line feed of 50Ω is introduced to the given rectangular shape radiating patch antenna. The antenna is suitable for application such as Mobile satellite services 2.2GHz is realized.
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Any Inverted F Antenna (IFA) basically has aa short circuiting pin (or plate), planar element (rectangular in shape) placed on a ground plane, and a mechanism to feed the planar part. Inverted F antenna can be understood to be a modification of the monopole in which top section is folded such that it becomes parallel to the ground plane. This leads to reducing the height of the antenna. Capacitance along with the input impedance to the antenna is introduced using this parallel section. Use of a short circuit stub helps in compensating this induced capacitance. The end of the stub is connected to the ground plane.
On the basis of analysis and formulations given above, we have observed the variations between various parameters like resonant frequency, reflection coefficient, mismatch loss, quality factor etc. with bias voltage. In order to compare the performance of the Gunn-active microstrip antenna with unloaded patch alone, calculation were also made for these parameters. The calculated values of relative power values at different angles and different biasing voltage for Gunn loaded patch and patch only are calculated and given in Table III.
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The motivation of borehole antenna design is to make a low-cost and simple broadband antenna (0.7–2 GHz) which can be inserted into a narrow borehole of interior diameter 34 mm. In such a case, an antenna formed of a monopole loaded with a resistive proﬁle (according to the Wu-King (WK) increasing resistive proﬁle from the feed-point to the open end of the antenna) appears the best compromise to obtain broadband characteristics in a narrow geometry[17–20]. To insert easilythe antenna in the centre of the borehole, we have positioned the antenna in a PVC (ε = 3.5) borehole with interior diameter a = 28 mm and exterior diameter rc = 34 mm as shown in Fig. 1; the antennas can be positioned in parallel or facing each other. The antenna is supposed to be fabricated on a 1.5 mm-thick FR4 substrate (ε = 4.4) with a ground plane on the backside, and it is fed bya 50 Ohms coaxial line. Parameter studies have led to the deﬁnition of an antenna made of a microstrip line (with conductor thickness 35 µm) with width of 3 mm and with length of 96 mm. In such a case, the real impedance of the antenna in the considered band is close to 50 Ω, and the ﬁrst resonant frequencyis 1.05 GHz. To lower the reﬂection at the feed- point and to minimize the reﬂection at the open end, a modiﬁed WK proﬁle has been considered. Thus, the resistance distribution per unit length is expressed by[19, 20]:
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3. M. Venkata Narayana , M. Sowmya, Govardhani Immadi, K. Swetha and R. Ranjana, Designing of co-axial feed Y-shaped micro-strip patch antenna for CDMA applications ,International Journal of Engineering Research and Applications , Vol. 2, Issue 3, May-Jun 2012, pp.100-103.
This paper presents the investigations of a bidirectional antenna using a probe-excited rectangular ring by using the dyadic Green’s function approach. The antenna characteristics depend on the probe length, ring width, ring height and ring length. In addition, the bidirectional patterns without side lobes are obtained for the appropriated ring length c from 0.10λ to 0.65λ. The side lobe is occurred when c ≥ 1.25λ. Furthermore, the beam-peak direction in E-plane is slightly tilted from z-axis because the probe position is not symmetry between the upper and lower sides of the ring. For H-plane pattern, the beam directs in +z and − z directions for any ring length of interest because of the symmetrical geometry in its plane. For the speciﬁed cross-sectional dimensions, the ring length is selected to achieve the optimum radiation pattern. Furthermore, the experiment was set up to verify the theoretical predictions. Apparently, the measured radiation pattern coincided with the calculated result except at around θ = 90 ◦ due to the edge eﬀect. The computed directivity of 4.43 dBi and measured gain of 4.40 dBi are obtained. The polarization of this antenna at the directions along the street cell (+z and − z directions) is linear because there is only one component of electric ﬁeld. Although the sinusoidal current distributions, disregarded mutual coupling and omitted reﬂection at the edge of the ring is assumed, the experimental results provide the validity of the theoretical predictions.
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ABSTRACT: Microstrip antennas have been one of the most innovative topics in antenna theory and design in recent years, and are increasingly finding application in a wide range of modern microwave systems. This paper focused about the coaxial probe fed rectangular microstrip patch antenna. The input impedance of a microstrip patch antenna is an important design parameter, which controls the radiated power and impedance bandwidth. In the case of a probe fed patch antenna, the total input impedance consists of the probe reactance in series with the patch impedance. This paper presents the design of antenna that operates in S-Band at frequency of 2.4GHz . This paper experimentally investigated the effect on performance characteristics of Rectangular microstrip patch antenna by varying various parameters such as width, height and position of feed. The proposed patch antenna is designed and simulated on HFSS 13.0 software. Ansoft HFSS employs the finite element method, adaptive meshing and brilliant graphics to give you unparalleled performance and insight to all of the 3D EM problems. After the simulation the effect on antenna performance characteristic such as return loss is studied , and 3D and 2D radiation pattern, gain vs frequency plot are obtained.
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Antennas are a very important component of communication systems. By definition, an antenna is a device used to transform an RF signal, traveling on a conductor, into an electromagnetic wave in free space. Antennas demonstrate a property known as reciprocity, which means that an antenna will maintain the same characteristics regardless if it is transmitting or receiving. Most antennas are resonant devices, which operate efficiently over a relatively narrow frequency band. An antenna must be tuned to the same frequency band of the radio system to which it is connected, otherwise the reception and the transmission will be impaired. When a signal is fed into an antenna, the antenna will emit radiation distributed in space in a certain way. A graphical representation of the relative distribution of the radiated power in space is called a radiation pattern.
In theory, all the parameters of the antenna have an eﬀect on the performance of the antenna, which include the two bevel angels on both sides of the metal plate, the size of the folded metal plate, and the size of the ground plane. In this section, the eﬀects of some key parameters on the proposed antenna are studied. The proposed antenna was simulated and optimized with the assistance of ANSYS high frequency structure simulator (HFSS) Ver. 12 .
The regular spiral antenna usually has spurious frequency which can make the signal at the operating frequency corrupt, spurious becomes a dominant factor in limiting quality and capacity. In order to suppress the spurious frequency and enhance bandwidth and gain, it can be achieved by adding either low pass or band pass filter that can be used to reject the spurious frequency. By using this method, it can increase the cost of the antenna.The Spiral antenna of the Defected Ground Structure (DGS) has gained much attention over the last few years for its ability of effectively suppressing spurious frequency and increasing the bandwidth.
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Recently, UWB antenna with circularly polarized characteristics is becoming more and more popular, because it not only allows the flexible orientation of the transmitter and receiver, but also reduces the power loss due to the polarization mismatch. Circular polarization can be generated under this condition: two orthogonal and linearly polarized modes with equal amplitude but with 90 o phase difference.
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