Although the worldwide demand for energy is increasing rapidly,the availability of current traditional resources(such as atomic and thermal power)is insufficient.Hence,artificial(man-made)energy sources are required.A...Although the worldwide demand for energy is increasing rapidly,the availability of current traditional resources(such as atomic and thermal power)is insufficient.Hence,artificial(man-made)energy sources are required.Advancements in wireless technology have raised the radio frequency(RF)levels in the environment.These RF waves are available at all times,unlike natural resources such as solar,hydro,and wind energy.The energy requirement and consumption of electronic devices have also been reduced over last decade.Hence,harvesting energy from RF waves and driving low-power devices are the simplest solutions.In the current work,a simplified monopole antenna,called a tri-stepped rectangular antenna for RF harvesting,is proposed.Here,the regular rectangular structure is modified to a step-like structure to achieve impedance matching and maximize the omni-directional gain at all mobile frequencies.This antenna functions with the LTE B5(850),GSM 900,GSM 1800,3G,4G,and ISM(2.4 GHz)systems.We have also demonstrated a proof-of-concept of energy harvesting using RF waves generated by mobile towers and Wi-Fi devices.The system can generate up to 12 mV(14.4 mW)and could charge a battery of rating 3.7 V,500 mAh.We anticipate this harvested energy to be used in driving the WSN node,Bluetooth devices,and mobile charging.展开更多
The finite element method(FEM) is applied to a thin substrate rectangular antenna with a shorting post. The results of the resonant frequencies are in good agreement with the experimental data. The input impedances a...The finite element method(FEM) is applied to a thin substrate rectangular antenna with a shorting post. The results of the resonant frequencies are in good agreement with the experimental data. The input impedances are calculated and the results are presented. In principle, this method is applicable to a microstrip antenna with shorting posts in arbitrary locations.展开更多
The circular sector patch antenna is studied in C-band (4 GHz - 8 GHz). In this paper, we present steps of designing the circular sector antenna then a comparison with a rectangular antenna in literature. High Frequen...The circular sector patch antenna is studied in C-band (4 GHz - 8 GHz). In this paper, we present steps of designing the circular sector antenna then a comparison with a rectangular antenna in literature. High Frequency Structure Simulator (HFSS) software is used to compute the gain, axial ratio, radiation pattern, and return loss S11 of proposed antenna. Based on the designed patch antenna, many phased arrays will be simulated using HFSS. The impact of distance between element, number of element and phase will be checked. Obtained results are analyzed and compared with literature.展开更多
A novel multi-band end-fire antenna array was designed, fabricated, and characterized. Analytical calculations were carried out to determine the critical antenna dimensions and the design was optimized using a 3D elec...A novel multi-band end-fire antenna array was designed, fabricated, and characterized. Analytical calculations were carried out to determine the critical antenna dimensions and the design was optimized using a 3D electromagnetic finite-element solver. The measured results were in good agreement with the designed results. The proposed antenna array exhibits multi-band capabilities which can be potentially used for applications that require a multi-band end-fire radiation pattern.展开更多
The broadband, narrow width, rectangular dielectric resonator antenna(RDRA) of aluminum nitride(εr=8.6) was designed and the effect of inclusion of air gap at the bottom of the dielectric resonator antenna(DRA),above...The broadband, narrow width, rectangular dielectric resonator antenna(RDRA) of aluminum nitride(εr=8.6) was designed and the effect of inclusion of air gap at the bottom of the dielectric resonator antenna(DRA),above the ground plane, was investigated. Gain around 7 dBi was obtained for DRA with air gap(DRAAG) over a broad bandwidth in upper X, Ku, and K bands. Further enhancement in gain could be obtained by placing a metal wall parallel to the length of DRA. However, due to the presence of metal wall, bandwidth was reduced. These structures with the metal wall are capable of operating over a wide band extending from Ku band to lower K band with the gain of around 10 dBi. CST Microwave Studio Software was used to simulate all these structures.Performance parameters of DRA with air gap were compared with several broadband DRA structures reported in recent literature. The proposed DRAAG with the metal wall in this paper is capable of operating over a wide bandwidth along with a significant gain.展开更多
A simple rectangular microstrip antenna on low dielectric constant substrate such as air for improved radiation beam performance is theoretically investigated. The conventional patch antenna fabricated on common subst...A simple rectangular microstrip antenna on low dielectric constant substrate such as air for improved radiation beam performance is theoretically investigated. The conventional patch antenna fabricated on common substrates always produces quite broader E plane pattern compared to its H plane. In the present investigation, the same microstrip antenna is designed on air substrate with a view to develop an efficient feed for parabolic reflector antenna, which shows an excellent radiation pattern with symmetrical 3 dB beam widths at its both E and H plane. The present antenna compared to conventional structure to show its excellence in the beam performance is presented. The complete quantitative analysis to explore such radiation beam characteristics for both the structures (conventional and the present one) is also presented in this paper. An easy and handful relationship between the length of patch antenna and its fringing length for different types of substrate is established in the background of 3 dB beam widths. The proposed idea has been verified through a commercial software package for a patch operating in X band and a concrete physical insight into the phenomenon is developed.展开更多
A Rectangular Microstrip Patch Antenna model is proposed using air as a substrate to study the characteristics of designed antenna. The dimensions of designed antenna are 17 mm × 16.66 mm with substrate at freque...A Rectangular Microstrip Patch Antenna model is proposed using air as a substrate to study the characteristics of designed antenna. The dimensions of designed antenna are 17 mm × 16.66 mm with substrate at frequency 3.525 GHz. In this paper, the simulation is performed by using software Computer Simulation Technology (CST) Microwave studio based on finite difference time domain technique. The characterization of the designed antenna was analyzed in terms of return loss, bandwidth, directivity, gain, radiation pattern, VSWR.展开更多
The aperture phase taper due to quadratic phase errors in the principal planes of a rectangular horn imposes signifi-cant constraints on the on-axis far-field gain of the horn. The precise calculation of gain reductio...The aperture phase taper due to quadratic phase errors in the principal planes of a rectangular horn imposes signifi-cant constraints on the on-axis far-field gain of the horn. The precise calculation of gain reduction involves Fresnel integrals;therefore, exact results are obtained only from numerical methods. However, in horns’ analysis and design, simple closed-form expressions are often required for the description of horn-gain. This paper provides a set of simple polynomial approximations that adequately describe the gain reduction factors of pyramidal and sectoral horns. The proposed formulas are derived using least-squares polynomial regression analysis and they are valid for a broad range of quadratic phase error values. Numerical results verify the accuracy of the derived expressions. Application examples and comparisons with methods in the literature demonstrate the efficacy of the approach.展开更多
Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of str...Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of strength as it travels over long distances. This is true in the military with missile, radar, and satellite systems, etc. Antenna arrays are commonly employed to focus electromagnetic waves in a certain direction that cannot be achieved perfectly with a single-element antenna. The goal of this study is to design a rectangular microstrip high-gain 2 × 1 array antenna using ADS Momentum. This microstrip patch array design makes use of the RT-DUROID 5880 as a substrate with a dielectric constant of 2.2, substrate height of 1.588 mm, and tangent loss of 0.001. To achieve efficient gain and return loss characteristics for the proposed array antenna, RT-Duroid is a good choice of dielectric material. The designed array antenna is made up of two rectangular patches, which have a resonance frequency of 3.3 GHz. These rectangular patches are excited by microstrip feed lines with 13 mm lengths and 4.8 mm widths. The impedance of the patches is perfectly matched by these transmission lines, which helps to get better antenna characteristics. At a resonance frequency of 3.3 GHz, the suggested antenna array has a directivity of 10.50 dB and a maximum gain of 9.90 dB in the S-band. The S parameters, 3D radiation pattern, directivity, gain, and efficiency of the constructed array antenna are all available in ADS Momentum.展开更多
Circularly polarized microstrip antenna is frequently realized by cutting the slot inside the patch and feeding it along the diagonal axis. In the reported literature, procedure to design them at any given frequency i...Circularly polarized microstrip antenna is frequently realized by cutting the slot inside the patch and feeding it along the diagonal axis. In the reported literature, procedure to design them at any given frequency is not available. In proposed work, circularly polarized slot cut circular microstrip antenna at 900 MHz is discussed. By studying the surface current distributions at two orthogonal modes, formulations in their resonant length are proposed. The frequencies calculated using them closely agree with simulated results. Using proposed formulation, procedure to design circular polarized antennas at different frequencies is presented that gives circular polarized response. Thus, proposed work will be helpful to design similar circular polarized circular microstrip antenna at any desired frequency.展开更多
The dual band equilateral triangular microstrip antennas are realized by cutting the slots of either quarter wave or half wave in length, inside the patch. In this design, however these simpler approximations of slot ...The dual band equilateral triangular microstrip antennas are realized by cutting the slots of either quarter wave or half wave in length, inside the patch. In this design, however these simpler approximations of slot length against the frequency do not give closer results for different slot lengths and there positions inside the patch. In this paper, the modal variations of slot cut patch antennas over wide frequency range are studied. It is observed that the slot does not introduce any mode but reduces the higher order mode resonance frequency of the patch and along with the fundamental mode realizes dual band response. The formulations of the resonant length for the mode introduce by the slots in these antennas are proposed. The resonance frequencies calculated using proposed formulations agree well with the simulated results with an error of less than 5%.展开更多
文摘Although the worldwide demand for energy is increasing rapidly,the availability of current traditional resources(such as atomic and thermal power)is insufficient.Hence,artificial(man-made)energy sources are required.Advancements in wireless technology have raised the radio frequency(RF)levels in the environment.These RF waves are available at all times,unlike natural resources such as solar,hydro,and wind energy.The energy requirement and consumption of electronic devices have also been reduced over last decade.Hence,harvesting energy from RF waves and driving low-power devices are the simplest solutions.In the current work,a simplified monopole antenna,called a tri-stepped rectangular antenna for RF harvesting,is proposed.Here,the regular rectangular structure is modified to a step-like structure to achieve impedance matching and maximize the omni-directional gain at all mobile frequencies.This antenna functions with the LTE B5(850),GSM 900,GSM 1800,3G,4G,and ISM(2.4 GHz)systems.We have also demonstrated a proof-of-concept of energy harvesting using RF waves generated by mobile towers and Wi-Fi devices.The system can generate up to 12 mV(14.4 mW)and could charge a battery of rating 3.7 V,500 mAh.We anticipate this harvested energy to be used in driving the WSN node,Bluetooth devices,and mobile charging.
文摘The finite element method(FEM) is applied to a thin substrate rectangular antenna with a shorting post. The results of the resonant frequencies are in good agreement with the experimental data. The input impedances are calculated and the results are presented. In principle, this method is applicable to a microstrip antenna with shorting posts in arbitrary locations.
文摘The circular sector patch antenna is studied in C-band (4 GHz - 8 GHz). In this paper, we present steps of designing the circular sector antenna then a comparison with a rectangular antenna in literature. High Frequency Structure Simulator (HFSS) software is used to compute the gain, axial ratio, radiation pattern, and return loss S11 of proposed antenna. Based on the designed patch antenna, many phased arrays will be simulated using HFSS. The impact of distance between element, number of element and phase will be checked. Obtained results are analyzed and compared with literature.
文摘A novel multi-band end-fire antenna array was designed, fabricated, and characterized. Analytical calculations were carried out to determine the critical antenna dimensions and the design was optimized using a 3D electromagnetic finite-element solver. The measured results were in good agreement with the designed results. The proposed antenna array exhibits multi-band capabilities which can be potentially used for applications that require a multi-band end-fire radiation pattern.
文摘The broadband, narrow width, rectangular dielectric resonator antenna(RDRA) of aluminum nitride(εr=8.6) was designed and the effect of inclusion of air gap at the bottom of the dielectric resonator antenna(DRA),above the ground plane, was investigated. Gain around 7 dBi was obtained for DRA with air gap(DRAAG) over a broad bandwidth in upper X, Ku, and K bands. Further enhancement in gain could be obtained by placing a metal wall parallel to the length of DRA. However, due to the presence of metal wall, bandwidth was reduced. These structures with the metal wall are capable of operating over a wide band extending from Ku band to lower K band with the gain of around 10 dBi. CST Microwave Studio Software was used to simulate all these structures.Performance parameters of DRA with air gap were compared with several broadband DRA structures reported in recent literature. The proposed DRAAG with the metal wall in this paper is capable of operating over a wide bandwidth along with a significant gain.
文摘A simple rectangular microstrip antenna on low dielectric constant substrate such as air for improved radiation beam performance is theoretically investigated. The conventional patch antenna fabricated on common substrates always produces quite broader E plane pattern compared to its H plane. In the present investigation, the same microstrip antenna is designed on air substrate with a view to develop an efficient feed for parabolic reflector antenna, which shows an excellent radiation pattern with symmetrical 3 dB beam widths at its both E and H plane. The present antenna compared to conventional structure to show its excellence in the beam performance is presented. The complete quantitative analysis to explore such radiation beam characteristics for both the structures (conventional and the present one) is also presented in this paper. An easy and handful relationship between the length of patch antenna and its fringing length for different types of substrate is established in the background of 3 dB beam widths. The proposed idea has been verified through a commercial software package for a patch operating in X band and a concrete physical insight into the phenomenon is developed.
文摘A Rectangular Microstrip Patch Antenna model is proposed using air as a substrate to study the characteristics of designed antenna. The dimensions of designed antenna are 17 mm × 16.66 mm with substrate at frequency 3.525 GHz. In this paper, the simulation is performed by using software Computer Simulation Technology (CST) Microwave studio based on finite difference time domain technique. The characterization of the designed antenna was analyzed in terms of return loss, bandwidth, directivity, gain, radiation pattern, VSWR.
文摘The aperture phase taper due to quadratic phase errors in the principal planes of a rectangular horn imposes signifi-cant constraints on the on-axis far-field gain of the horn. The precise calculation of gain reduction involves Fresnel integrals;therefore, exact results are obtained only from numerical methods. However, in horns’ analysis and design, simple closed-form expressions are often required for the description of horn-gain. This paper provides a set of simple polynomial approximations that adequately describe the gain reduction factors of pyramidal and sectoral horns. The proposed formulas are derived using least-squares polynomial regression analysis and they are valid for a broad range of quadratic phase error values. Numerical results verify the accuracy of the derived expressions. Application examples and comparisons with methods in the literature demonstrate the efficacy of the approach.
文摘Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of strength as it travels over long distances. This is true in the military with missile, radar, and satellite systems, etc. Antenna arrays are commonly employed to focus electromagnetic waves in a certain direction that cannot be achieved perfectly with a single-element antenna. The goal of this study is to design a rectangular microstrip high-gain 2 × 1 array antenna using ADS Momentum. This microstrip patch array design makes use of the RT-DUROID 5880 as a substrate with a dielectric constant of 2.2, substrate height of 1.588 mm, and tangent loss of 0.001. To achieve efficient gain and return loss characteristics for the proposed array antenna, RT-Duroid is a good choice of dielectric material. The designed array antenna is made up of two rectangular patches, which have a resonance frequency of 3.3 GHz. These rectangular patches are excited by microstrip feed lines with 13 mm lengths and 4.8 mm widths. The impedance of the patches is perfectly matched by these transmission lines, which helps to get better antenna characteristics. At a resonance frequency of 3.3 GHz, the suggested antenna array has a directivity of 10.50 dB and a maximum gain of 9.90 dB in the S-band. The S parameters, 3D radiation pattern, directivity, gain, and efficiency of the constructed array antenna are all available in ADS Momentum.
文摘Circularly polarized microstrip antenna is frequently realized by cutting the slot inside the patch and feeding it along the diagonal axis. In the reported literature, procedure to design them at any given frequency is not available. In proposed work, circularly polarized slot cut circular microstrip antenna at 900 MHz is discussed. By studying the surface current distributions at two orthogonal modes, formulations in their resonant length are proposed. The frequencies calculated using them closely agree with simulated results. Using proposed formulation, procedure to design circular polarized antennas at different frequencies is presented that gives circular polarized response. Thus, proposed work will be helpful to design similar circular polarized circular microstrip antenna at any desired frequency.
文摘The dual band equilateral triangular microstrip antennas are realized by cutting the slots of either quarter wave or half wave in length, inside the patch. In this design, however these simpler approximations of slot length against the frequency do not give closer results for different slot lengths and there positions inside the patch. In this paper, the modal variations of slot cut patch antennas over wide frequency range are studied. It is observed that the slot does not introduce any mode but reduces the higher order mode resonance frequency of the patch and along with the fundamental mode realizes dual band response. The formulations of the resonant length for the mode introduce by the slots in these antennas are proposed. The resonance frequencies calculated using proposed formulations agree well with the simulated results with an error of less than 5%.
