Manufacturing of 3D-metallic electromagnetic metamaterials for feedhorns used in radioastronomy and satellite communications

Abstract

The electromagnetic metamaterials at microwaves frequencies are well established in industrial applications nowadays. Recent research has shown that a specific kind of metallic metamaterial can contribute to improve the performance of the microwave feedhorns used in radioastronomy and satellite telecommunications. In this article, we theoretically justify this argument finding a new type of meta-ring with a record bandwidth in terms of cross-polarization, and we explore the manufacturability of these particular metamaterials, successfully fabricating a meta-ring and applying it to a novel and very compact prototype microwave antenna which covers a 2:1 bandwidth.1 The usable frequency is the centre frequency of the transmission/reception band.2 Surprisingly finding a notable electromagnetic benefit, explained in section 2.

A metamaterial with applications in broad band antennas used in radio astronomy and satellite communications

“…In the simulations, a plane wave is reflected on a metamaterial containing an E-field probe over its surface. By comparing the E-field probed in the same position with and without the presence of the metamaterial under test, we can subtract the incoming and reflected signals to obtain the reflection coefficient and surface impedance for each 𝑆 or 𝑃 polarization from equations (2.6) and (2.5) (more details are given in [5][6][7]11]).…”

“…Simplified configurations of the top-plated (left) and "inverted L" (center) corrugations of the metamaterial studied in [11], where 𝑒 = 0.4 mm, 𝑙 = 1.66 mm, 𝑑 = 6.5 mm and the free space between adjacent teeth of the corrugations is 0.25 mm. Right: transverse section of the top-plated (top) and "inverted L" (bottom) topologies.…”

“…In [7] we theorized on cross-polarization of feed-horn antennas and we presented the topology of a new metamaterial able to surpass some limitations of corrugated horns. In [11] we explored the manufacturability of such a metamaterial using different techniques. In this work, we present a prototype of a meta-horn made of this metamaterial, which shows promising results.…”

A microwave blackbody target for cosmic microwave background spectral measurements in the 10–20 GHz range

“…The EM design was verified by combining two different models able to separately estimate both the total reflectivity, 𝑆 11 , due to the pyramids array (used a plane wave as excitation) and the coupling between the feedhorn and the load as arranged inside the cryostat (figure 10), so as to estimate the power intercepted by the load and the spillover generated by the mechanical gap between feedhorn and shield (1 mm, due to thermal needs and the manufacturing process of the meta-horn described in [28,29]. Although the simulation of the complete model is dominated by the 𝑆 11 of the feedhorn alone (especially at low frequency), however, it is powerful to evaluate the spillover component.…”

Dual-Polarized All-Metallic Metagratings for Perfect Anomalous Reflection

“…Moreover, the current designed and fabricated MGs mostly rely on dielectric substrates, be it in the microwave [7,30,33], mmWave [13] or optical [6,15] regimes. However, among the variety of applications in which MG devices can be utilized, systems intended for space exploration or communication satellites are of great importance [34,35]. For such purposes, devices should sustain extreme temperature conditions and properly operate under high levels of radiation, making the utilization of relatively sensitive dielectric materials highly undesirable.…”