Antenna Design and Microwave Propagation

Design of a microstrip patch antenna for USB dongle is reported which can be used for UMTS2100 operating frequency band. The designed antenna is very thin and can be accommodated in a USB dongle. The antenna is designed using IE3D software and results for return loss and gain are verified by measurement. Parametric studies are included to show the variations of gain, efficiency and other antenna parameters of microstrip patch antenna with dimensions.

A micromachined 300-GHz slotted waveguide antenna is demonstrated using a simple fabrication technique based on metal-coated SU-8 thick resist. The antenna is designed to be built from a four-layer structure of equal layer thickness. It is fully characterized, and the measured radiation patterns show excellent agreement with the simulation. An H-plane matched right-angle bend is integrated in the antenna in order to achieve reliable and accurate connection with standard waveguide flange. The micromachined antenna is directional and low-profile and may find applications in low-cost sensors and radars.

—This Paper presents Microstrip patch antenna for WiMAX communication system which operate at 5.8 GHz frequency band. The main objective of this paper is to design and observe the performance of the designed mi-crostrip patch antenna for different dielectric materials. The size of the designed antenna has been also miniaturized. Better performance is observed for FR4 and dupont-951 dielectric material. For FR4 radiation efficiency is-2.776 dB and total efficiency is-3.026 dB at 5.8 GHz, this indicates better performance. And for dupont-951 the return loss is much lower comparing to the other dielectric materials used in this research, which is-16.609 dB. Also for dupont-951 and FR4, VSWR is found 1.35 and 1.7 respectively which is desirable. Also the size of the antenna has been reduced. In this paper we also observed and analyzed the radiation pattern of far field region, gain, radiation efficiency and total efficiency for different dielectric materials.

Smart antennas in the recent days are considered interested for improving the performance of wireless communication in different field. Smart antennas as systems of antennas include huge variety of techniques that tries to increase the received signal strength, suppress the interfering signals, and hence increase the over all SNR of the system. The supreme objective of this paper is to provide an overview of the status of research in the area of smart antennas, and to relate it with the present scenario of wireless communication systems. Adding value to the paper it also briefly describes the different adaptive algorithms used in the smart antenna systems which are currently used for array processing LMS, RLS and CMA their variants like NLMS, MILMS, BBNLMS, NLVFFRLS, LCMA, OCMA, SMI etc. Moreover, it is also shown how smart antennas; can provide substantial additional improvement when used with TDMA and CDMA digital-communication systems for spatial processing. Direction of Arrival (DOA) is also consider as one of the important parameter of smart Antenna and hence discussed in the paper. In today scenario when demand for the spectrum is increasing very rapidly, proper usage of spectrum is must and smart antenna is one the emerging technology which can fill the requirement.

This Paper presents Microstrip patch antenna for WiMAX communication system which operate at 5.8 GHz frequency band. The main objective of this paper is to design and observe the performance of the designed microstrip patch antenna for different dielectric materials. The size of the designed antenna has been also miniaturized. Better performance is observed for FR4 and dupont-951 dielectric material. For FR4 radiation efficiency is-2.776 dB and total efficiency is -3.026 dB at 5.8 GHz, this indicates better performance. And for dupont-951 the return loss is much lower comparing to the other dielectric materials used in this research, which is -16.609 dB. Also for dupont-951 and FR4, VSWR is found 1.35 and 1.7 respectively which is desirable. Also the size of the antenna has been reduced. In this paper we also observed and analyzed the radiation pattern of far field region, gain, radiation efficiency and total efficiency for different dielectric materials.

In this paper, the enhancement of gain and bandwidth of a Minkowski frac-tal antenna (MFA) with defected ground structure is investigated. The antenna characteristics are studied for first and second iterations by considering complementary split ring resonators in the L-shaped modified ground plane. The dimensions of the MFA are optimized with computer simulation technology software and the fabricated antenna characteristics are measured using Vector Network Analyzer and Wave and Antenna Training System. From the simulation, the maximum gain of our proposed antenna has been found 5.2 dB. Both bandwidths obtained from simulation and measurement exceed 2 GHz. The results of simulation are in good agreement with measured ones. This proposed antenna is suitable for the applications of various 5G wireless communications. K E Y W O R D S 5G, CSRR, DGS, fractal antenna, wideband 1 INTRODUCTION The demands of compact size, low cost, and high-performance antennas are increasing day-by-day for both civilian and military applications. 1,2 For telecast real-time events, video conferences, AI-based vehicles, and air-traffic control, 5G technology is needed to transfer high-speed data up to 20 Gbps. 3 To get a wideband, compact size and multi-channel antenna for 5G applications with good efficiency, it is needed to modify the structure of the microstrip patch antenna. Various types of modifications such as slot-loaded and metamaterial-loaded patch, linear and nonlinear fractals, meandering line, fork-shaped patch, differential feeding technique, and so forth, are used in recent research works. 4-7 The use of fractal geometries in these antennas has shown to be a good strategy in order to obtain log periodical multiband behavior. 8,9 This is mainly due to the self-similarity property of fractals. 10 There are many fractal curves such as Koch curve, Cantor curve, Minkowski curve, Sierpinski gasket and each of them has space-filling property. 6,7 For the first iteration, both Koch Curve and Minkowski loop fractal antennas can provide gain and bandwidth of about 3.2 dB and 200 MHz, respectively. 11,12 Lots of research works have been carried out for the enhancement of gain and BW. By adding metamaterial, these This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

We study the distributional consequences of the Covid-19 pandemic's impacts on employment. Using CPS data on stocks and flows, we show that the pandemic has exacerbated pre-existing inequalities. Although employment losses have been widespread, they have been substantially larger in lower-paying occupations and industries. Individuals from disadvantaged groups, such as Hispanics, younger workers, those with lower levels of education, and women, have suffered both larger increases in job losses and larger decreases in hiring rates. Occupational and industry affiliation can explain only part of the increased job losses among these groups.

Salah satu jenis antena yang banyak digunakan pada komunikasi bergerak nirkabel adalah antena mikrostrip karena bentuknya yang sederhana, ringan serta lebih murah dalam hal perakitan. Antena mikrostrip sendiri terdiri dari berbagai macam bentuk geometri. Kajian ini mengulas perbandingan performansi antena mikrostrip single patch persegi panjang pada frekuensi 3,35 GHz dan antena mikrostrip six elements array pada frekuensi 2,35 GHz dan 3,35 GHz untuk komunikasi bergerak nirkabel. Parameter yang menjadi perbandingan diantaranya adalah : VSWR, gain, polarisasi dan pola radiasi. Hasil pengukuran antena menunjukkan bahwa VSWR yang didapat pada antena single patch persegi panjang pada frekuensi 3,35 GHz adalah 1,334. Sedangkan, pada antena six elements array pada frekuensi 2,25 GHz adalah 1,375 dan 3,35 GHz adalah 1,369. Gain pada antena single patch persegi panjang adalah 2,411 dB (pada frekuensi 3,35 GHz). Sedangkan pada antena mikrostrip six elements array didapat gain antena sebesar 5,318 dB (pada frekuensi 2,35 Ghz) dan 2,526 dB (pada frekuensi 3,35 Ghz). Polarisasi yang diharapkan untuk kedua antena tersebut adalah sirkular dan pola radiasinya adalah unidireksional. Nilai VSWR yang terukur kecil sehingga menunjukkan performa yang baik dari antena. Namun gain yang didapat relatif kecil meskipun masih layak digunakan. Kata kunci : mikrostrip, single patch persegi panjang, six elements array Abstract One type of antenna that is widely used in wireless mobile communication is a microstrip antenna. Microstrip antennas are widely used because of its simple, lightweight and does not require a huge cost in assembly. Microstrip antenna itself consists of various geometric shapes. The study reviews the performance comparison of a rectangular single patch microstrip antenna on the frequency of 3.35 GHz and a six elementss array microstrip antenna at a frequency of 2.35 GHz and 3.35 GHz for wireless mobile communications. The parameters to be compared are : VSWR, gain, polarization and radiation pattern. The results show that the antenna VSWR measurements obtained on a rectangular single patch microstrip antenna at a frequency of 3.35 GHz is 1.334. Meanwhile, the six elementss array microstrip antenna at a frequency of 2.25 GHz and 3.35 GHz is 1.375 is 1.369. Gain on a rectangular single patch microstrip antenna is 2.411 dB (at a frequency of 3.35 GHz). While the six elementss array microstrip antenna obtained amounting to 5.318 dB (at a frequency of 2.35 GHz) and 2.526 dB (at a frequency of 3.35 GHz). Polarization specified for both antenna is circular and the radiation pattern is unidirectional. Small measured VSWR values show the good performance of the antenna. But the gain obtained relatively small although still worth using.

Conventional antenna design is done either by analytical methods or computer electromagnetic methods (CEM). Then, the design is fabricated by printing of PCBs or machining.In antenna laboratory lectures, some of the parameters of the commercial of the shelf (COTS) antennas are presented to the students but antenna design can not be taught. Some universities have both antenna simulation softwares and fabricating capabilities. But most of them don't have these capabilities. Many different kind of antennas at many frequencies can be obtained with different configurations of pieces called “cell”. Thus, this new method can be used both for antenna design and training.

proposed antenna displays omnidirectional radiation characteristics in the H-plane and monopole-like radiation characteristics in the E-plane at the considered frequencies. The measured peak antenna gains against frequency are shown in . The average gain is about 2.36, 2.75, and 3.62 dBi for the 2.5, 3.5, and 5 GHz bands, respectively. As a result, the gain of the proposed antenna within the operating bands satisfies the requirements for WLAN/WiMAX systems.