A new design of a microstrip rectenna at 5.8 GHz for wireless power transmission applications

Due to the ever-increasing power demand, the need of electricity and eco-friendly power in every nook and corner of the world, many reaserch topics have been devoted to deal with this problematic. This paper is taking part of the proposed solutions with the presentation of a novel 5.8 GHz rectenna system for wireless power transmission applications. In one hand, a miniaturized 5.8 GHz circular polarized patch antenna has been designed and simulated by using the Advanced Design System (ADS). In the other hand, a rectifier structure has been investigated and optimized by the use of the Harmonic Balance method available in ADS. The circuit is based on 5 HSMS2820 Schottky diodes implemented in a voltage multiplier topology and a load resistance of 1 KOhm. Both of the structures have been validated by simulation and experimental results and good agreement has been concluded

A novel design of a fractal antenna for IMT and WiMAX applications

In this paper, a new planar monopole antenna is designed and fabricated for IMT and WiMAX applications. The antenna is based on the use of Sierpinski triangle with a modified ground structure consisting of T-shaped and small rectangular slots printed in the ground. The entire area of the proposed antenna is 55x50mm2 and it is printed on an FR-4 epoxy substrate and fed by a 50 Ohm microstrip line. This new design helps in enhancing both the reflection coefficient and the bandwidth. The electrical performance of the fractal antenna is investigated by the use of CST-MW and HFSS. The simulated results present good performance in terms of matching input impedance and radiation pattern. The electromagnetic results of the fractal antenna are in a good agreement with measurement results

Reduction of Mutual Coupling between Closely Spaced Microstrip Antennas Arrays Using Electromagnetic Band-gap (2D-EBG) Structures

Reducing mutual coupling is a key research area in design of compact microstrip antennas arrays. To minimize the overall size of the antennas arrays, the distance between them must be very small, as a result a strong mutual coupling is appears. Periodic structures can help to design a low profile of antennas arrays and enable to improve their performances by the suppression of surface waves propagation in a given frequency range. This paper proposes a novel configuration of mushroom-like electromagnetic band-gap (2D-EBG) structure created by microstrip technology placed between two antennas arrays to reduce the mutual coupling more than -33.24dB. When 13×2 EBG structures are used, the mutual coupling reduces to -59.36dB at the operation frequency 5.8GHz of the antennas arrays. A 26.12dB mutual coupling reduction is achieved, which proves that the surface wave is suppressed. The proposed configuration is designed, optimized, and miniaturized by using electromagnetic software CST Microwave Studio. The measured results show that there is a good agreement with the computed results

A Novel Low Cost Fractal Antenna Structure for ISM and WiMAX Applications

Different fractal structures have been widely used in many antennas designs for various applications. A fractal antenna is used for miniaturization and multiband operation. This paper presents a design of a dual-band fractal antenna fed by coplanar waveguide (CPW) transmission line. The proposed antenna is designed and fabricated on an FR4 substrate with a volume of 70x60x1.6mm3, resonates at 2.42-2.62GHz and 3.40-3.65GHz with a return loss less than -10dB. The design and simulation process is carried out by using CST-MW studio electromagnetic solver. Simulation results show that the resulting antenna exhibits an interesting dual frequency resonant behavior making it suitable for dual band communication systems including the ISM and WiMAX applications. Concerning the fabrication and measurement of the final prototype of this antenna, a good agreement is found between simulation and measurement results for both frequency bands

A novel compact CPW Band-stop filter using O-DGS configuration

A novel and compact multi-band stop filter using two different structures of circular DGS and circular DGS loaded with O-DGS unit, has good selectivity and  wide upper pass band performance  with good rejection based on defected ground structure (DGS) integrating a circular ring  resonator to suppress undesired spurious bands frequency or harmonics in radio frequency and microwave circuits is proposed. An equivalent circuit model has been derived for the both structures of circular DGS and circular DGS loaded. The presented filter has a compact size because the circular ring resonator is integrated in DGS, the both of them are etching in the ground plane. The proposed filter presents an optimization method for generating multi-band characteristics without using a periodic cells or other complicate topology. The simulated results by ADS Agilent are presented and compared with the results simulated by two others software: CST and HFSS. Good agreement between the three simulated results is observed

A Novel Configuration of a Microstrip Microwave Wideband Power Amplifier for Wireless Application

RF/microwave power amplifier (PA) is one of the components that has a large effect on the overall performance of communication system especially in transmitter system and their design is decided by the parameters of transistor selected. This letter presents a new concept of a wide-band microwave amplifier using scattering parameters that is often used in the radio frequency communication systemas an application of the active integrated antenna[1- 2]. This power amplifier operates from 1.75 GHz to 2.15GHz frequency and it is based on AT-41410 NPN transistor that has a high transition frequency of 10GHz. The proposed Single Stage PA is designed by microstrip technology and simulated with Advanced Design System (ADS) software. The simulation results indicate good performances; the small power gain (S21) is changed between 11.8 and 10dB. For the input reflection coefficient (S11) is varied between -11 and -22.5dB. Regarding the output reflection coefficient (S22) is varied between -13.1 and -18.7dB over the wide frequency band of 1.75-2.15GHz and stability without oscillating over a wide range of frequencies

A novel compact CPW tunable stop band filter using a new Z-DGS-resonator for microwave applications

The paper presents a novel very compact CPW bandstop filter. The designed structure consists of one unit of new Z-DGS resonator, placed on top layer of ground plane between the input and output this structure, which is excited by 50 ohm coplanar line. The designed filter can be used in X-Band applications as the band stop can be shifted to any other desired frequency by tuning the length of the Z-DGS. The proposed filter topology has as benefits good performances in terms of wide stop-band rejection, low insertion loss, high return loss, simple design and more small size (17.908 × 10 mm2) compared to other previous works those reported in literature. The stop-band width is from 3.96GHz to 6.21GHz, exhibits a 22,25 dB rejection bandwidth of 45% with high selectivity characteristic at the center frequency of 5.05 GHz

Design of Negative Resistance Oscillator with Rocord Low Phase Noise

The aim of this paper is to use a new design of a negative resistance microwave oscillator in order to fabricate oscillator with very good performance in terms of output power, efficiency, stability and phase noise. In this study the new concept of oscillator using distributed resonator and micro-strip circuit elements improve performances of our structure. A micro-strip microwave oscillator with low phase noise based on an NPN silicon planar epitaxial transistor has been designed, fabricated, and characterized. In this design, each step has been conducted by using Advanced Design System (ADS) and following a theoretical study which enable to optimize the different performances of the whole circuit. The oscillator produce a sinusoidal signal with spectrum power of 12.25 dBm at 2.45 GHz into 50 Ω load when polarized at Vcc=15V with DC to RF efficiency of 16. The obtained phase noise of -120 dBc/Hz at 100 Hz offset is the result of the use of high Q factor resonator and the depth study of the parameters of the oscillator. Simulation and measurement results are in good agreement

A Novel Design of a Microstrip Microwave Power Amplifier for DCS Application using Collector-Feedback Bias

This paper presents a 1.80GHz class-A Microwave power amplifier (PA). The proposed power amplifier is designed with single-stage architecture. This power amplifier consists of a bipolar transistor and improved by Collector-Feedback Biasing fed with a single power supply. The aim of this work is to improve the performance of this amplifier by using simple stubs with 50Ω microstrip transmissions lines. The proposed PA is investigated and optimized by utilizing Advanced Design System (ADS) software. The simulation results show that the amplifier achieves a high power gain of 13dB, output power rise up to 21dBm and good impedances matching ;For the input reflection coefficient (S11) is below than - 46.39dB. Regarding the output reflection coefficient (S22) is below than -29.898dB, with an overall size of about 93 x 59mm². By the end; we find that this power amplifier offers an excellent performance for DCS applications

A Compact Planar Low-Pass Filter Based on SRR-Metamateria

In this work, a novel design of a Microstrip Low-pass filter based on metamaterial square split ring resonators (SRRs) is proposed. The SRRs has been added to obtain a reduced size and high performances. The filter is designed on an FR-4 substrate having a thickness of 1.6mm, a dielectric constant of 4.4 and loss tangent of 0.025. The proposed low-pass filter is characterized by a cutoff frequency of 2.4 GHz and an attenuation level below than -20dB in the stopband. The LPF is designed, simulated and optimized by using two electromagnetic solvers CST microwave studio and ADS. The computed results obtained by both solvers are in good agreement. The total surface area of the proposed circuit is 18x18mm2 excluding the feed line, its size is miniaturized by 40% compared to the conventional filter. The experimental results illustrate that the filter achieves very good electrical performances in the passband with a low insertion loss of 0.2 dB. Moreover, a suppression level can reach more than 35 dB in the rejected band