Chandan Kumar Chakrabarty

Design of RF Energy Harvesting System for Energizing Low Power Devices

Electromagnetic energy harvesting holds a promising future for energizing low power electronic devices in wireless communication circuits. This article presents an RF energy harvesting system that can harvest energy from the ambient surroundings at the downlink radio frequency range of GSM-900 band. The harvesting system is aimed to provide an alternative source of energy for energizing low power devices. The system design consists of three modules: a single wideband 377› E-shaped patch antenna, a pi matching network and a 7-stage voltage doubler circuit. These three modules were fabricated on a single printed circuit board. The antenna and Pi matching network have been optimized through electromagnetic simulation software, Agilent ADS 2009 environment. The uniqueness of the system lies in the partial ground plane and the alignment of induced electric fleld for maximum current ∞ow in the antenna that maximizes the captured RF energy. The design and simulation of the voltage doubler circuit were performed using Multisim software. All the three modules were integrated and fabricated on a double sided FR 4 printed circuit board. The DC voltage obtained from the harvester system in the fleld test at an approximate distance of 50m from GSM cell tower was 2.9V. This voltage was enough to power the STLM20 temperature sensor.

Ultra-Wideband Antenna Array Design for Target Detection

In this paper, a four-element microstrip antenna array is presented. The array is composed of Wilkinson power dividers which act as feed network along with Dolph-Chebyshev distribution and four- identical patch antenna elements. The array elements are properly designed to have a compact size and constant gain against frequency. The simulated results show good agreement with the measured results for the fabricated antenna array. Measurement shows that the array has a peak gain of more than 12dBi with side-lobe level of i15dB at 6GHz. These characteristics make the antenna array suitable for UWB directional uses.

Design of an RF-DC conversion circuit for energy harvesting

The design of voltage multiplier module used for energy harvesting system from ambient at downlink radio frequency range (935.2 MHz-959.8 MHz) of GSM-900 is presented. The function of this voltage multiplier circuit is to convert the RF energy signal into DC voltage that can be used to energize the low power electronic devices. The design was based on the Villard voltage multiplier circuit. A 4-stage Schottky diode voltage multiplier circuit was designed, modeled, simulated, fabricated and tested for its performance. Multisim was used for the modeling and simulation work. Simulation and practical tests were carried out for various input power levels at the specified frequency band. The RF input power levels verses the output voltages at the nodes of the Villard network were recorded. The input for the voltage multiplier module was fed through an efficient matching network from an RF energy harvesting antenna which is designed at 377 Ω impedance. For a received signal of -27dBm (1.99) μW at the antenna modules produce a DC output voltage of 2.1 V across 100 kΩ load.

Design of Ultra Wideband slotted microstrip patch antenna

In this paper, the design of an Ultra Wideband slotted microstrip patch antenna is presented. The proposed antenna has good performance of UWB with impedance bandwidth between 1.78 GHz to 11.13 GHz. The antenna exhibits the return loss (S11) below −10 dB for the frequency range mentioned. Effects of design antenna parameters such as the slot (size, position and dimension), patch shape and feed width have been investigated to obtain a better S11 value. Results are obtained using CST Microwave Studio.

Circuit modeling of an UWB patch antenna

An ultra wideband (UWB) patch antenna is analyzed in this paper. The design uses FR-4 substrate with dielectric constant of 4.9 and thickness of 1.6 mm. Circuit model of such antenna is developed under AWR microwave office environment. Obtained results from simulating the antenna in CST microwave studio are then compared with the results taken from the Circuit Model.

An Impulse UWB Patch Antenna with Integrated Bandpass Filter

An Ultra wideband patch antenna is tested in this paper for Impulse UWB applications. The UWB patch antenna is integrated with UWB bandpass filter of desired operating frequency range. The design is on FR-4 substrate with dielectric constant of 4.4 and thickness of 1.6 mm. Impulse performance and angle of operation for such antenna are shown.

Circuit Modeling for Rectangular Printed Disc Monopole Antenna with Slot for UWB System

In this paper, a circuit model is done for rectangular printed disc monopole antenna with slot for ultra wideband application. For this circuit modeling, patch cavity model consists of series resistor and inductor which represent the surface resistance and surface inductance with the combination of LC circuit as the resonant circuit is introduced. Moreover, a slot is etched on the patch antenna and represented by a series LC circuit for its circuit model. The result is then repeated with modification done on the slot and also the circuit model. Finally return loss result for both antenna structure and circuit model were compared and discussed.

A compact ultra wideband antenna with WiMax band rejection for energy scavenging

Radio Frequency (RF) energy harvesting has been rapidly advancing as a promising alternative to existing energy scavenging system. A well designed broadband antenna such as ultra-wideband (UWB) antenna can be used as one of the major components in an RF energy scavenging system. This paper presents a compact UWB antenna showing good impedance matching over a bandwidth of 2.8 to 11 GHz, suiTable for broadband RF energy scavenging. Nevertheless, the antenna usage in wireless communication has a limitation due to the problem of interference between UWB system and other narrowband systems. Thus, the proposed antenna is successfully designed with a single band-notched at the targeted WiMAX operating band of 3.3 to 3.6 GHz.

Dielectric verification of FR4 substrate using microstrip bandstop resonator and CAE tool

This paper describes a method to determine the dielectric constant of FR4 substrate material at the operating frequency of 2.3 GHz. The method make used of computer aided engineering (CAE) tool and microstrip bandstop resonator for investigating the dielectric value of a material. In accordance with the data sheet provided by manufacturer which is 4.5 at 10 MHz, a set of preliminary dielectric values are selected in order to explain the proposed technique. Microstrip bandstop resonators with different dimension are designed and analyzed with the electromagnetic simulator. They are fabricated using conventional wet-etching process which is relatively economical compared to other method. After that, the actual responses of the square ring resonators are measured with the vector network analyzer. By matching up the simulation results to the measured results, dielectric values selected earlier are tuned accordingly. The obtained values are used to validate the accuracy of the proposed method. The method is simple to practice. It provides the beginners a fast way and relatively straightforward method in investigating FR4 materials for their research and learning.

Simulated Electromagnetic Field Profile Inside and Outside XLPE Power Cable due to Partial Discharge

The electromagnetic field profile due to partial discharge is simulated. The x, y and z components of the electric and magnetic fields are calculated at the azimuthal plane of the single core xlpe cable, at the near field and far field regions inside and outside the cable. The results from the simulation give indication that the propagation mode of partial discharge signal at near field is hybrid transverse electric & transverse magnetic mode. The propagation mode at the far field region inside the power cable is transverse electric magnetic; and the propagation mode of the partial discharge outside the cable is quasi transverse electric magnetic.