Cyrille Menudier

Global Synthesis Method for the Optimization of Multifeed EBG Antennas

This paper presents a novel technique for synthesizing a given radiation pattern from an EBG antenna with an array feed. The method determines the optimum sets of input waves and input impedances for the feed ports in order to perform simultaneously the radiation pattern and the impedance matching of all the radiating probes that form the array feed. The method is validated through a numerical design of an EBG antenna excited with four patch antennas. The structure is designed to radiate with a single lobe scanned at 𝜃=30∘ in the E-plane. The interactions between each patch inside the EBG resonator are characterized with the CST MWS software. The optimum weights and the input impedances which simultaneously perform the objective radiation and the matching of all feeding ports are calculated by the developed global synthesis method. The feed network is designed with the Agilent ADS software in order to perform the specified weights and the impedances matching.

EBG resonator antennas: State of the art and prospects

This article presents the recent developments on electromagnetic band gap (EBG) resonator antennas. After reminding the working principles of such radiating devices, a state of the art is presented to show main applications of these antennas including high directivity solutions, multiband devices, omnidirectionnal coverages, focal feeds for reflector and tuning. Finally, some prospects are given for future improvements.

EBG Focal Feed Design Optimization

Recent works have shown that the electromagnetic bandgap (EBG) antenna can be used as a reflector focal feed. The design of such feeds needs to take into account several parameters to obtain both high illumination performances and low reflector antenna side-lobe level. Among these EBG antenna parameters, the quality factor, the excitation probe used and the phase center location constitutes key elements to obtain high performances. This article presents useful design curves to conceive an efficient EBG focal feed. These curves have been used to realize a 30-GHz single-feed EBG device illuminating a side-fed offset Cassegrain antenna (SFOCA). Results show good performances in terms of aperture efficiency and radiation patterns of the reflector antenna compared to the Potter horn previously used with the same reflector.

Circularly polarized directive antenna with parasitc elements for wide band applications

This paper presents the design of a directive and circularly polarized antenna with parasitic elements over the [2.23-2.68] GHz frequency band. The objective of this work is to design an architecture parasitic antenna with single feed element that meets to the radiation objectives: a broadside directional beam with circular polarization over the [2.23-2.68] GHz frequency band.

Development of a remote wake Up System to drastically reduce standby power of electronic devices

In this article we present a new concept to minimize standby power of electronic devices. The proposed technology is based on RF energy transfer and DC conversion to wake up an electronic device (TV, home automation systems, etc.). In this work we present an integrated emitter and a receiver with suitable performances for home or industrial applications. This system covers the entire Industrial, Scientific and Medical (ISM) band between 2.4GHz and 2.48GHz. The originality of this work is based on the development of a direct-synthesis method to design the antennas of the emitter and the receiver. The technology used is optimal for industrial and massmarket applications. Moreover, another key-element concern the receiver composed of a rectifying circuit optimized for low RF power level (-20 dBm) and a self-maintained switch driven with the rectified voltage. The different parts of the design are presented, with a particular focus on antennas. The results are confirmed by experimental measurements and they are compliant with the expected distances.

Multidirectional Receiving System for RF to dc Conversion Signal: Application to home automation devices.

In this article, we present an original solution for radio frequency (RF) to dc conversion with multiple antennas. The presented device operates at 2.45 GHz. It combines passive parasitic element antennas (PEAs) and RF to dc converters. The proposed device collects the RF energy with six independent antennas and realizes the conversion and summation of the dc voltages. The objective is to perform uniform coverage of a room with a gain superior to a single and omnidirectional antenna. The typical application can be energy harvesting or detection for the command unit in home automation. This last application is our goal, and interest in the solution has been demonstrated through an application that aims at reducing standby mode consumption of electronic devices. The article focuses on the critical points to realize an efficient summation. The whole system has been designed and manufactured to work in rooms from 3 m to 15 m wide. The measured performances have been validated.

Switchable steerable square parasitic monopole array design using a genetic algorithm

This article presents a design of a planar 2D parasitic elements monopole array. This design is an active reconfigurable antenna for scanning beams applications in the azimuth plane. A 16% frequency-tuning bandwidth is achieved from 4.6 to 5.4 GHz band. The beams direction is controllable with on/off states that can be generated with switches laying between the elements and the ground plane.

X-band compact dual circularly polarized isoflux antenna for nanosatellite applications

— This paper presents an original solution to design a compact dual circularly polarized isoflux antenna (DCPIA) for nanosatellite applications. This kind of antenna has been previously designed in our laboratory, for a single circular polarization. This antenna is composed of a dual circularly polarized feed and a choke horn antenna. This feed is a cross-shaped slot in the ground plane which provides coupling between a patch and a ring microstrip line with two ports. It is located at the centre of a choke horn antenna. The simulated antenna presents an axial ratio (AR) lower than 3 dB and a realized gain (RG) close to 0 dB over a 400 MHz bandwidth (8.0-8.4GHz) at the limit of coverage (LOC), i.e. 65° whatever the azimuth angle (φ) and the port. A 20 dB matching for each port and 13 dB isolation characteristics between the two ports have been achieved on this bandwidth. It has been realized and successfully measured.

Reducing Electronic Device Standby Power Using a Remote Wake-Up System [Antenna Applications Corner]

In this article, we use a conversion chain to minimize standby-mode power consumption, detailing the different parts of the emitter and the receiver. The proposed technology is based on an efficient radio-frequency (RF) energy transfer and an RF-dc conversion circuit with a self-maintained switch that wakes up an electronic device [e.g., television (TV), home automation systems, etc.], using an integrated emitter and a receiver with performances suitable for home or industrial applications. The developed system works in the industrial, scientific, and medical (ISM) band (2.4-2.48 GHz).

Phase center study of the Electromagnetic Band Gap antenna

This paper is dedicated to the phase centre study of the Electromagnetic Band Gap (EBG) antennas. Such antennas can be used to feed a reflector and they represent a new passive technology to realize multi beam coverage at an attractive cost compared to usual systems with beam forming networks. This work aims at determining the relative position of the EBG antenna phase centre and the parameters which affect it. A performance study is also made to show that these devices reach good performances compared to classical feed like horns.