scholarly journals A Novel Ancient Coin-Like Fractal Multiband Antenna for Wireless Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhen Yu ◽  
Jianguo Yu ◽  
Xiaoying Ran ◽  
Chenhua Zhu

This study proposes a novel square-circle structure fractal multibroadband planar antenna, similar to an ancient Chinese coin-like structure, for second generation (2G), third generation (3G), fourth generation (4G), WLAN, and navigation wireless applications. The device is based on the principles and structural features of conventional monopole antenna elements, combined with the advantages of microstrip antennas and fractal geometry. A fractal method was presented for circular nested square slotted structures, similar to an ancient Chinese copper coin. The proposed antenna adapted five iterations on a fractal structure radiator, which covers more than ten mobile applications in three broad frequency bands with a bandwidth of 70% (1.43–2.97 GHz) for DCS1800, TD-SCDMA, WCDMA, CDMA2000, LTE33-41, Bluetooth, GPS (Global Positioning System), BDS (BeiDou Navigation Satellite System), GLONSS (Global Navigation Satellite System), GALILEO (Galileo Satellite Navigation System), and WLAN frequency bands, 16.32% (3.32–3.91 GHz) for LTE42, LTE43, and WiMAX frequency bands, and 10.92% (4.85–5.41 GHz) for WLAN frequency band. The proposed antenna was fabricated on a 1.6 mm thick G10/FR4 substrate with a dielectric constant of 4.4 and a size of 88.5 × 60 mm2. The measurement results reveal that the omnidirectional radiation patterns achieve a gain of 1.16–3.75 dBi and an efficiency of 40–72%. The good agreement between the measurement results and simulation validates the proposed design approach and satisfies the requirements for various wireless applications.

2013 ◽  
Vol 411-414 ◽  
pp. 917-921
Author(s):  
Dong Hui Wang ◽  
Wen Xiang Liu

There is no effectual navigation method to deep space aerocraft until now. Global Navigation Satellite System (GNSS) is a candidate. Its feasibility was analyzed according to the deep space geometry coverage characteristics. The antenna elevation was optimally designed to maximum the signal coverage performance in deep space. Simulation Results show that the best antenna elevation is 50-90 degrees. At the height of geosynchronous orbit, the average PDOP is 8.63, and at the height of lunar orbit, the positioning accuracy can only be achieved by km level.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoying Ran ◽  
Zhen Yu ◽  
Tangyao Xie ◽  
Yao Li ◽  
Xiuxia Wang ◽  
...  

A novel two-iteration binary tree fractal bionic structure antenna is proposed for the third generation (3G), fourth generation (4G), WLAN, and Bluetooth wireless applications in the paper, which is based on the principles of conventional microstrip monopole antenna and resonant coupling technique, combined with the advantages of fractal geometry. A new fractal structure was presented for antenna radiator, similar to the tree in nature. The proposed antenna adapted two iterations on a fractal structure radiator, which covers mobile applications in two broad frequency bands with a bandwidth of 44.2% (1.85–2.9 GHz) for TD-SCDMA, WCDMA, CDMA2000, LTE33-41, and Bluetooth frequency bands, and 11.5% (4.9–5.5 GHz) for WLAN frequency band. The proposed antenna was fabricated on a G10/FR4 substrate with a dielectric constant of 4.4 and a size of 50 × 40 mm2. The good agreement between the measurement results and the simulation results validate that the proposed design approach meet the requirements for various wireless applications.


2019 ◽  
Vol 2 (2) ◽  
pp. 11-18
Author(s):  
Budiani Fitria Endrawati ◽  
Adhe Yusphie ◽  
Arum Prastiyo Putri ◽  
Azam Fadhil A ◽  
Mohammad Saiful R ◽  
...  

Balikpapan is one of the cities in East Kalimantan with unique characteristic of the region. The characteristics of the region and the height of the area from the sea surface of the city of Balikpapan is one of the factors, therefore need to be designed a tool to detect weather especially in Balikpapan city. The device design using Global Navigation Satellite System (GNSS) Wind Turbine. The measurement results are based on temperature, humidity and wind speed. From the measurement of temperature, humidity and wind speed obtained an average of 30.97oC; 73.49% and 2.91 m/s. According to method World Meteorological Organization, temperature, humidity and wind speed data is accepted.


2019 ◽  
Vol 16 (1) ◽  
pp. 172988141983024 ◽  
Author(s):  
Pengfei Zhang

With the networking of four Global Navigation Satellite Systems, the combination of multi-constellation applications has become an inevitable trend, and there will be more and more visible satellites that can be participated in ship positioning. However, the computational complexity increases sharply, which greatly improves the load capacity of the receiver’s data processor and reduces the output frequency of the positioning result. To achieve the balance between positioning accuracy and computational complexity, a new fast satellite selection algorithm based on both of geometry and geometric dilution of precision contribution is proposed. Firstly, this article analyzes the geometry characteristics of the least visible satellites has minimum geometric dilution of precision that meet the positioning requirements and makes clear the layout of their elevation angles and azimuth angles. In addition, it derives the relationship of geometric dilution of precision and the visible satellites layout and gets geometric dilution of precision contribution of each satellite. Finally, based on the observation data of JFNG tracking station of the Multi-Global Navigation Satellite System (GNSS) Experiment trial network, the positioning error and the elapsed time of GPS/Beidou Satellite Navigation System and GPS/Beidou Satellite Navigation System/Russian Global Orbiting Navigation Satellite System (GLOANSS) are compared. Simulation results show that the algorithm solves the problem that there are a lot of matrix multiplications and matrix inversions in the traditional satellite selection algorithm, and the new algorithm can reduce computational complexity and increase receiver processing speed.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jin Wang ◽  
Qin Zhang ◽  
Guanwen Huang

AbstractThe Fractional Cycle Bias (FCB) product is crucial for the Ambiguity Resolution (AR) in Precise Point Positioning (PPP). Different from the traditional method using the ionospheric-free ambiguity which is formed by the Wide Lane (WL) and Narrow Lane (NL) combinations, the uncombined PPP model is flexible and effective to generate the FCB products. This study presents the FCB estimation method based on the multi-Global Navigation Satellite System (GNSS) precise satellite orbit and clock corrections from the international GNSS Monitoring and Assessment System (iGMAS) observations using the uncombined PPP model. The dual-frequency raw ambiguities are combined by the integer coefficients (4,− 3) and (1,− 1) to directly estimate the FCBs. The details of FCB estimation are described with the Global Positioning System (GPS), BeiDou-2 Navigation Satellite System (BDS-2) and Galileo Navigation Satellite System (Galileo). For the estimated FCBs, the Root Mean Squares (RMSs) of the posterior residuals are smaller than 0.1 cycles, which indicates a high consistency for the float ambiguities. The stability of the WL FCBs series is better than 0.02 cycles for the three GNSS systems, while the STandard Deviation (STD) of the NL FCBs for BDS-2 is larger than 0.139 cycles. The combined FCBs have better stability than the raw series. With the multi-GNSS FCB products, the PPP AR for GPS/BDS-2/Galileo is demonstrated using the raw observations. For hourly static positioning results, the performance of the PPP AR with the three-system observations is improved by 42.6%, but only 13.1% for kinematic positioning results. The results indicate that precise and reliable positioning can be achieved with the PPP AR of GPS/BDS-2/Galileo, supported by multi-GNSS satellite orbit, clock, and FCB products based on iGMAS.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Tao Shi ◽  
Xuebin Zhuang ◽  
Liwei Xie

AbstractThe autonomous navigation of the spacecrafts in High Elliptic Orbit (HEO), Geostationary Earth Orbit (GEO) and Geostationary Transfer Orbit (GTO) based on Global Navigation Satellite System (GNSS) are considered feasible in many studies. With the completion of BeiDou Navigation Satellite System with Global Coverage (BDS-3) in 2020, there are at least 130 satellites providing Position, Navigation, and Timing (PNT) services. In this paper, considering the latest CZ-5(Y3) launch scenario of Shijian-20 GEO spacecraft via Super-Synchronous Transfer Orbit (SSTO) in December 2019, the navigation performance based on the latest BeiDou Navigation Satellite System (BDS), Global Positioning System (GPS), Galileo Navigation Satellite System (Galileo) and GLObal NAvigation Satellite System (GLONASS) satellites in 2020 is evaluated, including the number of visible satellites, carrier to noise ratio, Doppler, and Position Dilution of Precision (PDOP). The simulation results show that the GEO/Inclined Geo-Synchronous Orbit (IGSO) navigation satellites of BDS-3 can effectively increase the number of visible satellites and improve the PDOP in the whole launch process of a typical GEO spacecraft, including SSTO and GEO, especially for the GEO spacecraft on the opposite side of Asia-Pacific region. The navigation performance of high orbit spacecrafts based on multi-GNSSs can be significantly improved by the employment of BDS-3. This provides a feasible solution for autonomous navigation of various high orbit spacecrafts, such as SSTO, MEO, GEO, and even Lunar Transfer Orbit (LTO) for the lunar exploration mission.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Fahad Alhomayani ◽  
Mohammad H. Mahoor

AbstractIn recent years, fingerprint-based positioning has gained researchers’ attention since it is a promising alternative to the Global Navigation Satellite System and cellular network-based localization in urban areas. Despite this, the lack of publicly available datasets that researchers can use to develop, evaluate, and compare fingerprint-based positioning solutions constitutes a high entry barrier for studies. As an effort to overcome this barrier and foster new research efforts, this paper presents OutFin, a novel dataset of outdoor location fingerprints that were collected using two different smartphones. OutFin is comprised of diverse data types such as WiFi, Bluetooth, and cellular signal strengths, in addition to measurements from various sensors including the magnetometer, accelerometer, gyroscope, barometer, and ambient light sensor. The collection area spanned four dispersed sites with a total of 122 reference points. Each site is different in terms of its visibility to the Global Navigation Satellite System and reference points’ number, arrangement, and spacing. Before OutFin was made available to the public, several experiments were conducted to validate its technical quality.


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