60 GHz foam‐based antenna for near‐field focusing

Abstract

An innovative way to manufacture a sectoral horn antenna with a biconvex dielectric lens is presented. The antenna focuses on the near-field signal in the H-plane to illuminate a linear array for example. It is made of only two symmetrical pieces of foam and a metallic support. A prototype is manufactured and measured at 60 GHz to verify its focusing properties and validate the technological process.Introduction: Nowadays, near-field focusing antennas are mainly used for imagery sensing, and characterisation of materials or biomedical devices. By increasing the working frequency, they could be used for point-to-point communication inside a device. Higher frequencies allow a larger bandwidth for high rate transmission.Such a system includes two different parts. The first one is the radiating source which creates a plane wavefront. The second one corrects the phases in order to focus the signal at the desired focal zone in front of the antenna.Several types of antennas already exist to focus in the near-field. An array of patches [1] or slotted waveguides [2] can be used. Lenses can also focus in the near-field. A metallic horn with a dielectric lens has already been manufactured [3]. This kind of system can be used to feed a reflect-or transmit-array [2], but it can directly be used to communicate with a receiver if it has the same capability of focusing.In this Letter, a sectoral horn antenna is presented, loaded with two biconvex lenses. In the following Section, the shapes of the two lenses are designed and the final prototype is simulated. In the subsequent Section, the technological process is presented in order to manufacture the lenses (in particular the dielectric constant). Then the measurement results at 60 GHz are compared with simulation results to validate the prototype.

A Multi‐Objective Optimization‐Based Reflective Metasurface for Enhanced Multi‐Point Focusing With Diffraction Suppression

“…It effectively concentrates microwave energy to the receiving antenna or device (Buffi et al., 2010; Nepa & Buffi, 2017). With ongoing technological advancements, different NFF solutions have been proposed, such as metal reflectors (Surhone, 2010), planar Fresnel zone plates (Karimkashi & Kishk, 2011), and planar microstrip arrays (Bor et al., 2014). In recent years, the development of metasurface technology has brought new vitality to NFF technology.…”

Near-field focused planar transmitarray with low profile design for microwave power transmission

“…Near-field focusing (NFF) can be realized by various antenna structures, such as parabolic reflector antennas [5], dielectric lens antennas [6], microstrip phased array antennas [7,8,9], and planar Fresnel zone plate (FZP) lens [10,11] and so on. However, the traditional parabolic reflector antenna and dielectric lens antenna are large in size and difficult to process.…”

Research and Design of a Dual-band Reflective Foused Metasurface for Wireless Power Transfer

“…Theoretically, electromagnetic waves from the transmitting source can be focused at a certain point in near-field region within the boundary 2D 2 /λ. Since the last century, NFF has been realized through various antenna structures, such as parabolic reflector [6], dielectric lens antenna [7], microstrip phased array [8][9][10][11], and planar Fresnel zone plate [12,13]. However, the development of NFF in a WPT system has been hindered because of the high cost of processing parabolic reflectors, the complexity of microstrip array feeding, and the low efficiency of planar Fresnel zone plate lens.…”