Hybrid of monopole and dipole antennas for concurrent 2.4- and 5-GHz WLAN access point

2009 ◽  
Vol 51 (5) ◽  
pp. 1206-1209 ◽  
Author(s):  
Jui-Hung Chou ◽  
Saou-Wen Su
Keyword(s):  
2016 ◽  
Vol 3 (1) ◽  
pp. 31-39
Author(s):  
F Ammar ◽  
Hanafi Hanafi

WiFi bekerja pada band 2,4 GHz dan 5 GHz. Standar WiFi yang bekerja pada frekuensi ini antara lain IEEE802.11g dan IEEE802.11a. Pada penelitian ini dilakukan pengukuran terhadap transfer rate download dan upload data dengan standar IEEE802.11g dan IEEE802.11a. Pengukuran dilakukan pada kanal Line of Sight (LOS), menggunakan dua buah laptop yang dihubungkan dengan Access Point (AP) standar IEEE802.11g dan IEEE802.11a.  Hasil penelitian diperoleh, pada standar IEEE802.11g, transfer rate download dan upload data tertinggi 2.662,54.KB/s dan 2.549,60 KB/s, dan terendah 484,50.KB/s dan 477,40 KB/s, sedangkan pada standar IEEE802.11a, transfer rate download dan upload data tertinggi 8.104,68 KB/s dan 5.744,24 KB/s, dan terendah 872,24 KB/s dan 465,38.KB/s. Pada standar IEEE802.11g, transfer rate download dan upload data pada sinyal terendah hingga di bawah 35% dan 30%, dari transfer rate download dan upload data tertinggi. Pada standar IEEE802.11a, transfer rate download dan upload data pada kualitas sinyal terendah hingga di bawah 20% dan 30%, dari transfer rate download dan upload data tertinggi. Kemampuan transfer rate download data Standar IEEE802.11a, 2–3 kali lebih baik pada kondisi kualitas sinyal tertinggi, dan tidak lebih dari 2 kali pada kondisi kualitas sinyal terendah, dibandingkan kemampuan transfer rate download data standar IEEE802.11g. Kemampuan transfer rate upload data Standar IEEE802.11a, 1,4–3 kali lebih baik pada kondisi kualitas sinyal tertinggi, dan 1-3 kali lebih baik pada kondisi kualitas sinyal terendah, dibandingkan kemampuan transfer rate upload data standar IEEE802.11g.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Andy Bubune Amewuda ◽  
Ferdinand Apietu Katsriku ◽  
Jamal-Deen Abdulai

Wi-Fi has been an amazingly successful technology. Its success may be attributed to the fact that, despite the significant advances made in technology over the last decade, it has remained backward compatible. 802.11ac is the latest version of the wireless LAN (WLAN) standard that is currently being adopted, and it promises to deliver very high throughput (VHT), operating at the 5 GHz band. In this paper, we report on an implementation of 802.11ac wireless LAN for residential scenario based on the 802.11ax task group scenario document. We evaluate the 802.11ac protocol performance under different operating conditions. Key features such as modulation coding set (MCS), frame aggregation, and multiple-input multiple-output (MIMO) were investigated. We also evaluate the average throughput, delay, jitter, optimum range for goodput, and effect of station (STA) density per access point (AP) in a network. ns-3, an open source network simulator with features supporting 802.11ac, was used to perform the simulation. Results obtained indicate that very high data rates are achievable. The highest data rate, the best mean delay, and mean jitter are possible under combined features of 802.11ac (MIMO and A-MPDU).


2014 ◽  
Vol 7 (5) ◽  
pp. 551-556 ◽  
Author(s):  
Churng-Jou Tsai ◽  
Bo-Yuan Tsai

In this paper, a novel and compact center-fed dual-band WiFi printed antenna is presented. This antenna is designed using two different arms which correspond to the oscillation points of the dual band, and uses parasitic capacitance and U-shaped microstrip line to match and control the necessary bandwidth. The measured frequency bandwidth of this antenna is 2.3–2.61 GHz (310 MHz, 12.7%) at 2 GHz, and the high-frequency bandwidth is 4.82–5.84 GHz (1020 MHz, 19.1%) at 5 GHz, which meets the requirements for applications in global WiFi communication. This PCB antenna is double-sided, long, and narrow; its size is 7 × 45.9 × 1 mm3; it can be applied to wireless access point; and it has a near-omni-directional radiation pattern. The design, analysis, and measured results of this proposed antenna will be presented.


Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2141
Author(s):  
Junghoon Cha ◽  
Choon-Seong Leem ◽  
Ikhwan Kim ◽  
Hakyoung Lee ◽  
Hojun Lee

In this study, we proposed an indoor broadband dual-polarized 2 × 2 MIMO (multiple-input and multiple-output) antenna having dimensions of 240 mm × 200 mm × 40 mm, for application in 5G wireless communication systems. The proposed antenna comprised two vertically polarized circular monopole antennas (CMAs), two horizontally polarized modified rectangular dipole antennas (MRDAs), and a ground plane. The distance between the two MRDAs (MRDA1 and MRDA2) was 70.5 mm and 109.5 mm in the horizontal (x-direction) and 109.5 mm vertical (y-direction) directions, respectively. Conversely, the distance between the two CMAs (CMA1 and CMA2) was 109.5 mm and 70.5 mm in the horizontal (x-direction) and vertical (y-direction) directions, respectively. While the CMAs achieved broadband characteristics owing to the optimal gap between the dielectric and the driven radiator using a parasitic element, the MRDAs achieved broadband owing to the optimal distance between the dipole antennas. The observations in this experiment confirmed that the proposed could operate in the 5G NR n46 (5.15–5.925 GHz), n47 (5.855–5.925 GHz), n77 (3.3–4.2 GHz), n78 (3.3–3.8 GHz), and the n79 (4.4–5 GHz) bands. Moreover, it exhibited a wide impedance bandwidth (dB magnitude of ) of 101% in the 2.3–7 GHz frequency range, high isolation (dB magnitude of ), low envelope coefficient correlation (ECC), gain of over 5 dB, and average radiation efficiency of 87.19%, which verified its suitability for application in sub-6 GHz 5G wireless communication systems.


2019 ◽  
Vol 1 (2) ◽  
pp. 62-71
Author(s):  
Muchlis Budiono ◽  
Zainudin Bonok ◽  
Syahrir Abdussamad
Keyword(s):  

Gangguan frekuensi dapat mengakibatkan kerusakan pada sistem telekomunikasi baik komunikasi dalam bentuk voice maupun data, oleh karena itu gangguan pada frekuensi ini harus segera mungkin di atasi agar komunikasi dapat berjalan dengan lancar.Tujuan penelitian ini adalah untuk mempelajari proses dalam penanganan gangguan frekuensi radio di Loka Monitor Spektrum Frekuensi Radio Gorontalo (kasus gangguan pada frekuensi yang ditetapkan untuk radar cuaca BMKG Provinsi Gorontalo Stasiun Meteorologi Kelas I Djalaluddin). Metode yang digunakan yaitu studi observasi lapangan dan diskusi bersama beberapa pihak terkait guna melakukan pengambilan data lapangan yang diperlukan. Alat dan bahan yang digunakan dalam penelitian ini yaitu: GPS Garmin Montana 650s, RS PR 100, RS Antenna HE300, FieldFox N9918A, Antenna BWA 5 GHz TP-Link CPE 610, Spectrum Analyzer Anritsu MS2720T, Teropong Steiner, Inverter, Laptop, dan Mobil Monitoring. Dengan menggunakan spectrum analyzer dapatdilihat terjadinya interferensi disebabkan adanya sinyal lain yang frekuensinya sama dan besarnya daya sinyal pengganggu. Ukuran yang digunakan untuk menilai kualitas sinyal terhadap gangguan interferensi dinyatakan dengan C/I (dB). Frekuensi radar BMKG Provinsi Gorontalo mengalami gangguan pada frekuensi kerjanya yaitu pada range 5540 – 5660 MHz, Gangguan frekuensi pada radar cuaca BMKG Gorontalo dalam bentuk interferensi disebabkan adanya banyak penggunaan frekuensi BWA 5 GHz yang menduduki frekuensi kerja radar BMKG, Selanjutnya Tim Loka Monitor Spektrum Frekuensi Radio Gorontalo melakukan clearance frekuensi radio di wilayah Kota Gorontalo dari range frekuensi 5540 MHz sampai dengan 5660 MHz. Selanjutnya melakukan pengecekan langsung ke access point yang menjadi sumber pengganggu radar cuaca BMKG. Adapun penanganan gangguannya yaitupemilik diberikan teguran selanjutnya perangkat dimatikan sementara, serta pemilik diminta mengisi surat pernyataan dan mengalokasikan perangkat pada frekuensi yang sesuai perizinannya


2020 ◽  
Vol 12 (12) ◽  
pp. 1995
Author(s):  
David Sánchez-Rodríguez ◽  
Miguel A. Quintana-Suárez ◽  
Itziar Alonso-González ◽  
Carlos Ley-Bosch ◽  
Javier J. Sánchez-Medina

In recent years, indoor localization systems based on fingerprinting have had significant advances yielding high accuracies. Those approaches often use information about channel communication, such as channel state information (CSI) and received signal strength (RSS). Nevertheless, these features have always been employed separately. Although CSI provides more fine-grained physical layer information than RSS, in this manuscript, a methodology for indoor localization fusing both features from a single access point is proposed to provide a better accuracy. In addition, CSI amplitude information is processed to remove high variability information that can negatively influence location estimation. The methodology was implemented and validated in two scenarios using a single access point located in two different positions and configured in 2.4 and 5 GHz frequency bands. The experiments show that the methodology yields an average error distance of about 0.1 m using the 5 GHz band and a single access point.


2008 ◽  
Vol 50 (9) ◽  
pp. 2403-2407 ◽  
Author(s):  
Saou‐Wen Su ◽  
Jui‐Hung Chou
Keyword(s):  

Author(s):  
S. Reddy Vamshidhar Reddy ◽  
Sanjay Dhar Roy

AbstractUtilization of unlicensed spectrum under licensed assisted access ensuring fair co-existence with Wi-Fi networks is a good solution to address immense usage of mobile data. Radio communication operation of LTE in unlicensed frequency band is referred as LTE-unlicensed (LTE-U) or LTE-licensed assisted access. In this paper, we consider a HGNW in which coverage area of Wireless-Fidelity (Wi-Fi)’s Access Point is integrated within the LTE-U small base station’s cellular network coverage area. To overcome the disadvantages of existing LTE-U technics like carrier sense adaptive transmission and listen before talk, we proposed a new methodology i.e., sense before transmit in this paper by adopting a transmit power control mechanisms using reciprocity theorem based on the channel state information to assign the secondary carriers in the uplink as well as in the downlink directions in the unlicensed spectrum to carry the traffic. In our proposal, LTE-U users are allowed to use the unlicensed spectrum provided that the interference produced at Wi-Fi users due to LTE-U activities is remained below a certain threshold. We evaluated the performance of proposed network model in terms of outage probability and achievable throughputs.


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