Anne Claire Lepage

RCS Reduction With a Dual Polarized Self-Complementary Connected Array Antenna

In this paper, a wideband dual polarized self-complementary connected array antenna with low radar cross section (RCS) under normal and oblique incidence is presented. First, an analytical model of the multilayer structure is proposed in order to obtain a fast and reliable predimensioning tool providing an optimized design of the infinite array. The accuracy of this model is demonstrated thanks to comparative simulations with a full wave analysis software. RCS reduction compared to a perfectly conducting flat plate of at least 10 dB has been obtained over an ultrawide bandwidth of nearly 7:1 at normal incidence and 5:1 (3.8 to 19 GHz) at 60° in both polarizations. These performances are confirmed by finite element tearing and interconnecting computations of finite arrays of different sizes. Finally, the realization of a

Maximal Bandwidth of an Archimedean Spiral Antenna Above a Reflector

28 \times 28

Size, gain and bandwidth trade-offs for wideband diamond dipole with AMC reflector

cell prototype and measurement results are detailed.

Compact multi-band antenna and matching circuit for LTE low frequency bands

In this letter, the maximal achievable bandwidth of an Archimedean spiral antenna above a reflector is investigated. This bandwidth is defined by the frequency range where the gain in the broadside direction is higher than the case without a reflector. To determine this theoretical bandwidth, we propose an analysis consisting in replacing the Archimedean spiral antenna by a bidirectional elliptical plane-waves source above an infinite reflector. Thanks to this approximation, it is possible to evaluate this bandwidth with a simple analytical expression, which is defined by constructive interferences between two plane waves. The maximal bandwidth obtained from this formula is equal to 5:1 for a metallic reflector. Simulations and measurements are then presented in order to confirm this result.

Wideband stepped reflector for Archimedean spiral antenna

Compact and directive ultra-wideband antennas are required in variety of applications. Directional wideband antennas can be designed by using a reflector to redirect the energy back in half space and increase the gain. Use of artificial magnetic conductors (AMC) as reflectors for antennas allows reduction in the thickness of an antenna using traditional perfect electrical conductors (PEC) reflectors. The lateral size of the reflector also has an important effect on the antenna performance. In this paper, we study the trade-offs involved in the design of an AMC used as a reflector for broadband diamond dipole antenna by simulating various sizes of the reflector.

Compact patch antenna for Automatic Identification System (AIS)

This article introduces a coupled planar antenna which is made of a driven monopole antenna and a parasitic element fed through a via. These elements are etched in a no-ground part, which is small compared to the Printed Circuit Board (PCB) size. The antenna has several resonant modes enabling three wide operating bands, which respectively cover the LTE700/GSM850/900, GSM1800/1900/UMTS, LTE2300/2500/2700 and LTE3400/3600 standards. A prototype whose size is suitable for mobile phones has been realized. There is a good agreement between simulation and measurement in term of return loss. Also in this publication, an analysis of the impact of this antenna on the performance of power amplifiers is conducted. It is followed by a practical solution of matching circuit. The effects of the antennas impedance and the matching circuit are demonstrated through the study of the output power of the power amplifier.

Wideband low profile antennas and metamaterials

This paper presents the advantages of a Perfect Electric Conductor (PEC) used as a stepped reflector for an Archimedean spiral antenna. Such a configuration is used to improve the broadside gain over a relative bandwidth of 145%.

Low profile, directive and ultra wideband antenna on a high impedance surface

This paper presents a radiating element developed for the space AIS application. This element is a compact sized and reduced mass microstrip patch antenna integrating frequency resonant adjustment devices. Theoretical and experimental results with good agreement are presented.

Design and measurement of a thin and light absorbing material for space applications

This paper presents an overview on how to design a wideband directive antenna with metamaterials. Two different kinds of antenna are analyzed. First, a Bow-Tie antenna is optimized close to an Artificial Magnetic Conductor. Afterwards, an Archimedean Spiral antenna is associated in close vicinity of a Loaded Electromagnetic Band Gap material. Classical and original methodologies are discussed in order to help the wideband antenna designer.