Karim Tekkouk

Wideband and Large Coverage Continuous Beam Steering Antenna in the 60-GHz Band

A wideband and continuous beam steering flat antenna is proposed in the 60-GHz band. The antenna consists of two layers and is made of two parts: 1) a feeding network and 2) a slotted plate. The relative rotation movement between the two antenna parts generates a phase gradient across the radiating part, and a continuous beam is generated in the upper hemisphere. The mechanical movement between the two antenna parts is facilitated by the use of gap waveguides; therefore, no electrical contact is needed between the two metallic parts. To validate the antenna concept, an antenna has been designed and fabricated in the 60-GHz band. Good agreement has been obtained between the simulations and the measurements. The antenna field of view is up to ±60°. The antenna bandwidth is up to 13% for VSWR <2. The loss within the antenna structure is estimated to be around 0.86 dB.

Continuous beam steering antenna with large 2D coverage for 5G applications

A gap waveguide continuous beam steering antenna is proposed in the 60-GHz band for 5G applications. The antenna is composed of two parts: i) a quasi-TEM feeding network, ii) a slotted radiating plate. The relative mechanical rotation between the two parts generates a phase gradient across the radiating part and the beam radiated in the upper hemisphere can be scanned continuously. The antenna is developed in hollow waveguide with a contactless technology to ease the mechanical movement between the antenna parts. The proposed antenna has been validated numerically and experimentally in the 60-GHz band. Very good agreement has been obtained between simulations and measurements. The antenna field of view reaches ±60°. and its bandwidth equals 13% for VSWR<2. The losses within the structure are 0.5dB. Finally a large 2D beam coverage can be obtained by combining frequency scanning and mechanical rotation of the two antenna parts; these results are also confirmed experimentally.

Corporate-Feed Slotted Waveguide Array Antenna in the 350-GHz Band by Silicon Process

A corporate-feed slotted waveguide array antenna with broadband characteristics in terms of gain and reflection in the 350-GHz band is proposed. To improve the etching accuracy of the thin laminated plates with the conventional diffusion bonding process, a new fabrication process has been developed, where the etching accuracy is lower than ±5 μm. In this process, the laminated plates are made with silicon wafers and etched by deep reactive ion etcher process. These are gold plated then bonded with the diffusion bonding process. The estimated effective conductivity of the gold plated wafer is 1.6 × 107 S/m. The loss per unit length is 1.1 dB/cm. A 16×16 element array antenna has been designed and fabricated in the 350-GHz band with the proposed process. The broadband characteristic in terms of the antenna gain is demonstrated for the first time by measurement in this frequency band. The 3-dB down gain bandwidth is 50.8 GHz in simulation and is 44.6 GHz in measurement.

Multiplexing Antenna System in the Non-Far Region Exploiting Two-dimensional Beam Mode Orthogonality in the Rectangular Coordinate System

A multiplexing antenna system is proposed for high data rate wireless transmission applications in the non-far region. The system is composed of two identical flat rectangular antennas directed toward each other and separated by a distance. Each antenna radiates four beam modes with 2-D orthogonality in the rectangular coordinate system by means of a passive and low-loss beam forming network. Thanks to the orthogonality relation among the modes up to four independent channels in the same direction with the same frequency and polarization can be carried and the signal demultiplexing is facilitated in the reception side. To validate the proposed concepts, the antennas have been designed and fabricated in the E-band around 78.5 GHz. Based on that, the multiplexing system has been experimentally tested. Good agreement between simulations and measurements has been obtained.

High data rate wireless transmission in the non-far zone with 2D orthogonal beams

A high data rate transmission system for short range application is proposed. The system is composed of two identical flat rectangular antennas separated by a distance in the non-far zone. Each antenna generates four two-dimensional orthogonal beams by a passive and low-loss beam-forming network. Thanks to the orthogonality relation between the beams, several channels with the same frequency and in the same direction could be carried and the signal demultiplexing is facilitated in the reception side. Wireless transmission using two-dimensional orthogonality of the aperture field distribution in the rectangular coordinate system is achieved, which is equivalent to Orbital Angular Momentum (OAM) transmission using two-dimensional orthogonality in the cylindrical coordinate system. To validate the proposed concept a transmission system has been designed, fabricated and tested in the E-band around 78.5 GHz. The system generates 4 orthogonal beams and compared to a Single Input Single Output (SISO) system the spectral efficiency could be enhanced up to fourfold.

Corporate-feed slotted wavguide array antenna at 350 GHz band by silicon process

A corporate feed slotted waveguide array antenna with broadband characteristics in term of gain in the 350 GHz band is achieved by measurement for the first time. The etching accuracy for thin laminated plates of the diffusion bonding process with conventional chemical etching is limited to ±20μm. This limits the use of this process for antenna fabrication in the submillimeter wave band where the fabrication tolerances are very severe. To improve the etching accuracy of the thin laminated plates, a new fabrication process has been developed. Each silicon wafer is etched by DRIE (deep reactive ion etcher) and is plated by gold on the surface. This new fabrication process provides better fabrication tolerances about ±5μ™ using wafer bond aligner. The thin laminated wafers are then bonded with the diffusion bonding process under high temperature and high pressure. To validate the proposed antenna concepts, four antenna prototypes have been designed and fabricated in the 350 GHz band. The 3dB-down gain bandwidth is about 35GHz by this silicon process while it was about 15GHz by the conventional process using metal plates in measurement.