This research developed a small RLSA antenna that mimics the specification of a Wi-Fi antenna that is available in markets, which is a Back Fires 17 dBi LAN antenna. This research used the size of the back fires antenna as the size for the RLSA antenna. Base on this size, we designed and simulated 71 RLSA antenna models. Among them, we chose a best model and fabricated its prototype. We measured the prototype and found that the measurement result fits the simulation result, thus verifying the correctness of the antenna model. Furthermore, we analysed that with the same size, our RLSA antenna has better performance compared to the back fires antenna, in term of gain (0,53 dB higher), and in term of bandwidth (1075 MHz wider). We also found that our RLSA antenna is lighter and thinner compared to the back fires antenna. We also test the RLSA antenna in real condition for indoor and outdoor communication link. The test showed that the RLSA antenna can performs properly.
RLSA antennas were suggested by several researches as Wi-Fi antennas in addition to panel antennas. Therefore, this paper researched the possibility of this suggestion. We used the size of an available in market 16 dBi panel antenna (225 mm 2 ) as the size for our developed RLSA antenna. Based on this size, we developed 60 RLSA models using extreme beamsquint technique and simulated them. We then chose a best model with a best performance. The best model was then fabricated and measured. The simulation and measurement results show that the developed RLSA antenna has better performance compared to the 16 dBi panel antenna in term of gain (0.25 dB higher) and bandwidth (570 MHz wider). The RLSA antenna also tested as antenna for a Wi-Fi device and it showed good performance.
The design of small radial line slot array (RLSA) antennas requires more than simply decreasing the antenna radius, which leads to the problem of high reflection. To overcome this inconvenience, we introduce a technique for constructing small RLSA antennas with low reflection by cutting full-sized ones. We designed 42 ordinary full-size RLSA models with a radius of 75 mm and then cut them into 42 half RLSAs and 42 quarter RLSAs. The areas of the half RLSAs and the quarter RLSAs are equal to those of full-sized RLSAs with radii of 53 mm and 37 mm, respectively. Our results show that the gain of the quarter RLSA is less than that of the full RLSA by only 1 dB, whereas theoretically, the gain should decrease by 6 dB due to the size reduction. Interestingly, the gain of the half RLSAs is greater that of the full RLSA by 1 dB, whereas theoretically, a decrease of 3 dB was expected due to the size reduction. The half RLSA and the quarter RLSA also perform well in terms of reflection coefficient and bandwidth, thus demonstrating the efficacy of the cutting technique in constructing small low reflection RLSAs.
Dual-beam half Radial Line Slot Array (RLSA) antennas were introduced for the first time in this article. Their uniqueness lies in the fact that only half model of RLSA antennas was used instead of full circle models to ensure they are applicable in small devices. Moreover, the slots were placed on the antenna's background, which is unusual, to produce a beam on the backside. It is important to note that the half RLSA and the antenna background used to produce the beam affected the power flow orientation within the antennas' cavity, thereby, causing a center frequency shift problem. This led to the proposal of a technique of frequency design shift to overcome this problem by designing and simulating 120 dual-beam half RLSA models after which the best model was fabricated and measured to verify the simulation. The results showed the possibility of designing dual-beam antennas with symmetrical beams having 10.1 dB gain, 30° and 150° directions, and 37° beamwidths. It was discovered that this gain is 3 dB lesser than the value for a single beam antenna and this is suitable based on the theory of beam splitting. Moreover, the antenna was also able to perform low reflection and quite broad bandwidth for Wi-Fi needs. The design of the antenna was further verified based on the similarity between the results of the measurement and simulation.
This research is motivated by the poor learning outcomes of the first-grade students at SDN Grogol Utara 09. So far, in learning Mathematics, teachers only emphasize cognitive aspects. Where the teacher explains a lot of material and gives questions to students without paying attention to how well students understand the subject. This in turns push the students to get bored quickly and are not enthusiastic about learning. As a result, interest and learning outcomes in mathematics decrease. The purpose of this study was to find out whether student learning outcomes have increased in terms of place value in numbers using the demonstration method and glass media in grade 1 students at SDN Grogol Utara 09. This research was conducted in two cycles on the material place value in numbers. Based on the results of the improvement, it turned out that it was able to increase the achievement of grade 1 students at SDN Grogol Utara in Mathematics. It was proven by obtaining the class average scores in the 1st cycle improvement, namely 62.5 and 79.5 in the 2nd cycle improvement. It was stated that there was an increase of 17 points. Thus, the use of the Demonstration method with glass media in learning Mathematics about determining place value in numbers turns out to be able to improve grade 1 student achievement at SDN Grogol Utara 09 in Mathematics
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.