A New Frequency Reconfigurable Antenna Using Proximity Fed Technique for Wireless Applications

This electronic paper presents an innovative technologyfor efficient use of the radio spectrum. This new frequencyreconfigurable rotatable antenna is intended for wirelessapplications such as WLAN, WiMAX and Bluetooth mobileapplications. The working principle of this proposed work isto print square patches mounted on the same circular dielectricsubstrate feed by a proximity coupling to eliminate the noisesignal transmission and problems related to interference. Thethree positions correspond to an operating frequency controlledby a bipolar step-by-step engine. An optimization of the structureusing the FEM finite element method as well as a comparisonwith other structures recently realized are detailed in this paper.The final numerical simulation results are: WLAN 4.95-5.53 GHz(BW = 11%) Gain = 6.06 dBi, WiMAX 3.35-3.75 GHz (BW =11.2%) Gain = 7.48 dBi and Bluetooth 2.3-2.51 GHz (BW =8.7%) Gain = 17.78 dBi

Development of a hardware emulator of a nanosatellite gyroscope

The gyroscope sensor has multiple applications in consumer electronics, aircraft navigation, and control systems. Significant errors that match the corresponding data are a typical disadvantage of this sensor. This needs to be done by making error models that can be used to get the right level of measurement accuracy. For high-precision space applications, the navigation design system should take into account the angle random walk (N), bias instability error (B), and rate random walk (K) of the BMG160 gyroscope. For this reason, this paper shows how to use Allan Variance (AVAR) and Power Spectral Density (PSD) for the experimental identification and modeling of the stochastic parameters of the Bosch BMG160 gyroscope embedded in a nanosatellite in order to get an accurate gyroscope model. This work also demonstrates the principle of operation of the equivalent electronic model intended to carry out advanced simulations without recourse to the real material in order to avoid the problem of bad manipulation and availability of the material in order to reduce the time and cost of development. The interpretation of the Allan curves and the PSD obtained from the measurements collected over a long period is presented, as well as a comparison between the real raw data of the BMG160 gyroscope and the designed hardware emulator in both the time and frequency domains. This is done to evaluate the accuracy of the gyroscope model emulating the real sensor in laboratory simulations. The experimental results show that the signals from the emulator and the BMG160 gyroscope are quite close. Therefore, the proposed prototype could be an optimal solution for laboratory calculations and simulation

An ultra wideband antenna for Ku band applications

This paper presents a candidate ultra wideband antenna for Ku-band wireless communi- cations applications, analyzed and optimized by the finite element method (FEM). This three-dimensional modeling was realized and compared with published antennas for val- idate the performances of the proposed antenna. Its design is based on the insertion o fseveral symmetrical slots of different sizes on the ground plane of a mono-layer patch antenna to overcome the main limitation of the narrow bandwidth of patch antennas. The proposed antenna, made on an FR-4 epoxy mono-layer substrate with a defected ground plane (dielectric constant εr = 4,4, loss tangent tan δ = 0,02 and thickness hs = 1.6 mm). The simulated numerical results obtained are very satisfying; Bandwidth = 10.48 GHz from f1 = 9.34 GHz to f2 = 19.82 GHz, S11 = -34.17 dB, Voltage Stationary Wave Ratio VSWR = 1.04 , Gain = 6.27 dB

Reconfigurable ultra wideband to narrowband antenna for cognitive radio applications using PIN diode

Frequency reconfigurable antennas are very attractive for many wireless applications.They offer many advantages such as simplicity and compactness. In this electronicpaper, we propose a reconfigurable antenna operating in the S and C bands. Theproposed antenna uses a BAP65-02 RF diode to switch between the ultra widebandfrom 2.92 to 6.19 GHz to the narrowband from 2.92 to 3.93 GHz. The ultra widebandis obtained by a partial rectangular ground plane with a symmetrical rectangular slotand the narrowband is obtained by adding a parasitic element electrically connectedto the ground plane by the PIN diode when it is positively biased. This patch antennaoperates in the Federal Communications Commission band (FCC) and can be used forbiomedical applications such as radiometry imaging. The numerical simulation resultsbased on the finite element method and the finite integral method show a very goodagreement between them

Software calibration for AK8963 magnetometer based on optimal ellipsoidal fitting

With the rapid development of mechatronics, systems in package (SiP), in particular the MPU-9250 inertial measurement Unit 9DOF (MPU-6050 6DOF and AK8963 3DOF), are becoming ubiquitous in applications for autonomous navigation purposes. Nevertheless, they suffer from some accuracy problems related to axis misalignment, disturbances, and deviation over time that make them unable to work autonomously for a long time. This paper will present a simple and practical calibration method using a least-squares based ellipsoid fitting method to calibrate and compensate for the error interference of the AK8963 sensor. Towards the end of this paper, a comparison between before and after the calibration is presented to study the software compensation effect and the stability of the magnetic sensor under study

A New Frequency Reconfigurable Antenna Using Proximity Fed Technique for Wireless Applications

This electronic paper presents an innovative technology for efficient use of the radio spectrum. This new frequency reconfigurable rotatable antenna is intended for wireless applications such as WLAN, WiMAX and Bluetooth mobile applications. The working principle of this proposed work is to print square patches mounted on the same circular dielectric substrate feed by a proximity coupling to eliminate the noise signal transmission and problems related to interference. The three positions correspond to an operating frequency controlled by a bipolar step-by-step engine. An optimization of the structure using the FEM finite element method as well as a comparison with other structures recently realized are detailed in this paper. The final numerical simulation results are: WLAN 4.95-5.53 GHz (BW = 11%) Gain = 6.06 dBi, WiMAX 3.35-3.75 GHz (BW = 11.2%) Gain = 7.48 dBi and Bluetooth 2.3-2.51 GHz (BW = 8.7%) Gain = 17.78 dBi

UWB antenna with circular patch for early breast cancer detection

Breast cancer is the most common cancer in women. It has the highest incidence rate and the highest mortality rate. In recent years, the incidence of breast cancer has become more and more important, it is becoming the first tumor killer for women around the world. Early diagnosis is the most important parameter for detecting cancerous tissue to prevent serious consequences. In this electronic paper, we present a new design of an ultra-wide-band circular microstrip patch antenna operating in the recommended FCC band ([3.1 GHz - 10.6 GHz]) for the detection of breast tumors. The antenna is printed on an FR4 epoxy substrate with a dielectric permittivity r = 4.4 and loss tangent tan = 0.02. The results obtained are largely satisfying and prove that the proposed antenna is a candidate for biomedical applications

A low-cost IMU/GPS position accuracy experimental study using extended kalman filter data fusion in real environments

In a three-dimensional environment, the navigation of a vehicle in airspace, terrestrial space, or maritime space presents complex aspects concerning the determination of its position, its orientation, and the stability of the processing of the asynchronous data coming from the various sensors during navigation. In this context, this paper presents an experimental analysis of the position accuracy estimated by a low-cost inertial measurement unit coupled, by the extended Kalman data fusion algorithm, with a system of absolute measurements of a positioning system received from a GPS which designates the global positioning system. The different scenarios of the experimental study carried out during this work concerned three tests in a real environment, such as the navigation in a course inside the city of Rabat/Morocco with a moderate speed, a section on the highway at a speed of 120 Km/h and a circular path around a roundabout. The experimental results proved that the low-cost sensors studied are a good candidate for civil navigation applications

Study and design of an active magnetorquer actuator model for nanosatellites

This paper focuses on the study and the design of an air core magnetorquer model dedicated to the 1U CubeSat (10×10×10 cm3). The objective is to obtain a solution which is able to provide accurate attitude control while having the smallest possible dimensions, electrical power, and total mass. To this end, the first part will provide theoretical mathematical knowledge on the laws of the coil to design an electromagnetic air core actuator. Then, this paper presents comparisons of the performances obtained by varying the type of material and the shape of the coil. Towards the end, the effect of temperature variation in LEO orbit is taken into consideration to predict the generated magnetic moment