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In this work an overview of the different additive manufacturing techniques will be presented. Each technique will be compared in terms of dimensional accuracy, surface roughness, and quality taking into account the most suitable applications for each one. Then, two applications will be studied: (a) fast prototyping of waveguide component designs using professional grade 3D printers for electromagnetic...
In this paper, the fabrication of Ka band input filters by means of additive manufacturing technology is tested for space applications. Measurements of manufactured prototypes against recurrent filters designed with specifications used in real satellite communication systems are performed, and conclusions about the potential of the additive manufacturing technology for space applications are stated.
Purely passive, mechanically steered waveguide-fed horn arrays are good candidates to satisfy the current need for low-to-medium-profile antennas for mobile user terminals for SATCOM applications. In this work, a unique waveguide feed architecture is proposed, which enables the realization of grating lobe-free, wideband, low-profile waveguide-fed horn arrays operating with dual circular polarization...
In this paper an additive manufactured (AM) W-band monolithic feed chain is presented. The feed chain, which consists of a corrugated horn antenna and a turnstile orthomode transducer (OMT), operates over the entire W-band (75–110 GHz) and fulfills typical RF specifications for a chosen space-borne radiometer application (RL > 20 dB, IL < 1 dB and Xpol < −30 dB). Both the OMT and the horn...
This paper presents a circularly-polarized dual-band antenna for Ka-band satellite communications which operates simultaneously in both civil and military downlink (17.7–21.2 GHz) and uplink (27.5–31 GHz) bands. The antenna is composed of a metallic ridged cavity that is perforated with a crossed-slot. This cavity is excited in sequential rotation through four feeding coaxial cables, thus producing...
This paper will give an overview of the possibilities offered by the additive manufacturing processes to create integrated passive components. After the presentation of different technologies (inkjet printing, polymer 3D printing, ceramic stereolithography) and associated materials, concepts of antennas and filters will be described along with measured results. The paper will specifically highlight...
In this paper, a single-fed four-panel 4×1 patch array antenna operating at 2.43 GHz with switched beam capability is proposed. The design allows the beam to be switched between four discrete directions giving 360° coverage. The antenna beam is switched over the azimuth plane for Φ = 0°, Φ = 90°, Φ = 180°, and Φ = 270°. The beam control is achieved by using GaN-based HEMT SPDT switches. Only three...
For integration into flat mounting volumes in cars a new wideband antenna is presented covering all frequency bands for cell phone LTE and 5G starting with the LTE low band at 698 MHz up to the WLAN frequency bands at 6 GHz. The performance of the antenna as a single part is shown by way of measurement and simulation and a pair of antennas is measured in a car on a turntable regarding its mutual coupling...
In this paper, a technique to maximize the directivity of an antenna array is presented. It consists of a fed monopole and a loaded parasitic one. The nature and value of the load are obtained using the Uzkov equations that calculate the current weighting coefficients in the case of two separately fed antennas to maximize the gain and the directivity in one direction. Reconfigurability is achieved...
A wideband U-slot patch antenna with reconfigurable radiation pattern is investigated. The antenna composes three patches which are one coaxial-fed U-slot driven patch and two parasitic patches located near the two non-radiating edges of the middle driven patch. One varactor diode is installed in middle of each parasitic patch. Both beamwidth and main lobe direction can be tuned by controlling the...
A recently published paper presented a novel concept for obtaining frequency reconfigurable behavior by combining multiple antenna elements and weighting the feed signals for each element. In this paper, we clarify some concepts presented in that paper and analyze the antenna structure in more detail.
This paper presents the extraction of the modes resonating inside a mode-stirred reverberation chamber using the Matrix Pencil method. An increasing time-window technique is investigated as a process to discriminate the true modes and the spurious ones that appear due to the measurement noise.
The 4:th generation communication standard is constantly evolving with more features being added to the standard specifications. Carrier aggregation and higher order MIMO are examples of features used to support higher data rates. The addition of features puts new requirements on wireless devices and this increasing complexity implies that Over-the-Air testing is more important than ever. At the same...
Base station conformance and performance testing is traditionally carried out in a conducted manner, i.e. test instruments are connected via cables to physical ports on the base station. As the complexity of the base station transceiving circuitry increases and more and more antennas are added to the transceiving links, new measurement techniques based on Over-the-Air metrics are needed. This is especially...
A reconfigurable over-the-air chamber represents a reverberation chamber whose walls are lined with antennas that are terminated in reconfigurable impedances, allowing synthesis of a wide range of channel conditions for over-the-air testing of mobile wireless devices. While these chambers have potential for practical device testing, finding the right impedances to achieve the desired channel characteristics...
We present two configurations of multiport antennas for Multiple-input Multiple-output (MIMO) application. The configurations are comprised of three and four dual-polarized self-grounded bowtie antenna as the element, respectively. The MIMO performance of both antennas is evaluated in Random Line-of-Sight (Random-LOS) and Rich Isotropic Multipath (RIMP) channel models as two edge propagation environments...
In this paper we present a 3D wide-band measurement bench for Over-the-Air (OTA) tests. The setup is composed by twelve double-polarized antennas, placed around the Zone Under Test (ZUT), on three different elevation planes. A characterization of the ZUT was performed in order to assess the differences, in terms of amplitude and phase of the incident field, according to the frequency considered.
This paper presents a low-cost measurement method for MIMO antenna performance assessment based on the open-source OpenAirInterface initiative. A first measurement is presented with a prototype with 8 antennas at 2.6 GHz integrated into a 140×140×40mm femto cell and using Laser Direct Structuring (LDS) technique. The setup is validated trough a beamforming gain measurement in a MISO 4×1 configuration...
This paper shows the variation of clusters with the increasing number of antennas. The data was collected from the massive MIMO mobile measurement at 3.5 GHz, in line of sight (LoS) and non line of sight (NLoS) conditions, respectively. And the virtual measurement method is used to form the 64-element, 128-element and 256-element virtual antenna array from the 32-element antenna array. After estimating...
This work investigates the antenna mutual coupling effect on multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems with oscillator phase noises. Since the antenna correlation when taking the mutual coupling effect into account is smaller than that when the mutual coupling effect is omitted, it is shown that, at small antenna separations, the error rate performance...
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