Dielectric lens antennas for 300-GHz applications

Abstract Implementation of proper wireless links at submillimetre-wave and terahertz (THz) frequencies requires high-gain antennas. This simulation-based study investigates the performance of dielectric lenses and their feed antennas at 300 GHz. Parametric studies and electromagnetic simulations are used to determine the general lens properties, and the use of waveguide and on-chip antenna feeds is considered. The results show that the studied lens and feed structures can provide good, directive radiation patterns also with beam scanning

Thermal analysis of GaN/SiC-on-Si assemblies:effect of bump pitch and thickness of SiC layer

Abstract The ever-increasing requirements for high device performance and compact size drive the communications industry to lookfor new materials, technologies, and integration concepts. This simulation-based study investigates the thermal properties of a compact, heterogeneously integrated gallium nitride on silicon carbide (GaN-on-SiC) and silicon (Si) assembly. Thermal simulations and parametric studies are used to determine how the heat spreading and temperature levels in the lateral and vertical directions are affected by the thickness of the SiC layer and the distribution of the thermal interconnects. Results show that a SiC layer thinned down to 100 µm shows more pronounced differences in its thermal characteristics compared to thicker ones, especially in terms of its backside heating. Aspects related to practical implementations are also considered

Performance simulation of a 5G hybrid beamforming millimeter-wave system

Millimeter-wave systems are the next step to increase the data rate of 5G mobile communication networks. Hybrid analog-digital beamforming is one of the core technologies to enable millimeter-wave communication. Both the theoretical basics and the hardware design have been investigated in recent years. Current research projects like the European SERENA project strive to develop platforms to demonstrate the performance gain of complete systems. We present a simulation based analysis of a planned proof-of-concept system to evaluate the influence of design decisions and hardware impairments. We use a geometry-based stochastic channel simulator and simulate both certain hardware aspects and signal processing parts. We focus on the signal processing parts directly related to the hybrid architecture used for multi user MIMO precoding like the initial link acquisition and the data precoding. We use our own state-of-the-art algorithms for these parts

Hardware aspects of sub-THz antennas and reconfigurable intelligent surfaces for 6G communications

Abstract The need for unrestricted, high-quality, and high-speed communications in planned sixth generation (6G) wireless systems drives the development and research towards the sub-terahertz (sub-THz) bands which so far have been relatively unused for wireless communications applications. Additionally, the sub-THz bands have gained an increasing interest as a potential spectral region at which to go even beyond the well-known Shannon limits. This review paper provides a technological overview on some of the key hardware aspects of sub-THz wireless communications (at 100–300GHz), namely antennas, reconfigurable intelligent surfaces (RISs), and reconfigurable antenna systems based on state-of-the-art technologies reported in recent literature. Different technologies of antennas and RISs are compared to understand their possibilities and limitations, and to identify the most promising technological approaches to transform 6G from a vision into a commercially viable solution. The paper also presents the authors’ interpretations of possible hardware and design trends that can shape the future research directions

Broadband cross-slotted patch antenna for 5G millimeter-wave applications based on characteristic mode analysis

Abstract This article proposes a wideband differentially-fed dual-polarized magnetoelectric (ME) dipole for millimeter-wave (mm-Wave) applications. Various electric and magnetic characteristic modes of a slotted patch antenna are investigated and utilized effectively to create a stable broadside radiation pattern, covering 5G frequency bands from 24.25 GHz to 40 GHz. To implement this, the lifted ground (LGND) concept is applied to achieve a 57.1% impedance bandwidth for a single antenna element. Additionally, the three resonances of the antenna can be manipulated independently. The use of differential feeding allows more than 36 dB of port-to-port isolation across the entire operating band. The measured gains of the single element and 2×2 array are 8.4 dBi and 13.4 dBi, respectively. Also, the measured results indicate symmetrical E- and H-plane radiation patterns and cross-polarization levels lower than –26 dB.With the favorable electrical performance, compact size, simple structure and low-cost fabrication, the proposed ME dipole is a promising candidate for mm-Wave Antenna-in-Package (AiP) applications

OTA measurement technique for sub-THz integrated lens antennas

Abstract Moving to sub-THz frequencies introduces new challenges for wireless communications systems in terms of design, implementation, and testing. This paper presents a measurement technique for over-the-air (OTA) characterisation of sub-THz antennas at WR3.4 band (220‐330 GHz), and a silicon (Si) lens fed by an on-chip antenna is used as a test vehicle. In the proposed measurement technique, the received sub-THz AM-modulated test signal is downconverted to kHz-range using a square-law power detector. Measurements and simulations/calculations are used to compare several key antenna/link parameters. Agreement between the results is good, which shows that the proposed technique provides a good and less hardware-intensive alternative for sub-THz antenna measurements

Dual-band dual-polarized planar antenna for 5G millimeter-Wave antenna-in-package applications

Abstract This article presents a dual-band, dual-polarized antenna operating from 24 up to 40 GHz at 5G new radio (NR) millimeter-wave (mm-Wave) Frequency Range 2 (FR2) bands. A novel stacking arrangement of ring patches is proposed to achieve wide dual-band operation with stable gain. Two pairs of stacked ring patches operating at lower (24.25–29.5 GHz) and upper (37–40 GHz) FR2 bands are alternately integrated at four metal layers. The antenna offers a sharp roll-off and a filter-like response with radiation nulls between the operating bands due to the stacking configuration. The antenna is aperture-coupled and stripline-fed, and it conforms to the antenna-in-package (AiP) requirements. The proposed single antenna element and a 2 X 2 array are fabricated utilizing a standard commercial printed circuit board (PCB) fabrication facility. The measurement results show a decent agreement with the simulations in terms of impedance matching, isolation, radiation patterns, and realized gain. The proposed design is a promising candidate for 5G mm-Wave base station antenna arrays

Dual-polarized filtering antenna for mm-Wave 5G base station antenna array

Abstract This paper presents a dual-polarized filtering antenna designed for a 5G mm-Wave base station phased array. The out-of-band radiation of a stacked patch antenna is suppressed by embedding filtering structures along with radiating patches and feed network. Four radiation nulls can be tuned by introducing a combination of open-loop and hairpin resonators at appropriate locations, and a bandpass filtering response can be achieved. The antenna design principles and simulated performance are discussed. The antenna operates in n257 and n258 mm-Wave bands, demonstrating -10 dB impedance bandwidth at 24.25—29.5 GHz. The realized gain remains stable between 5 and 6 dBi at all the operating frequencies. The isolation between the ports and cross-polar discrimination remain better than 20 dB in all the covered frequency range

A study of the effects limiting the responsivity of a broadband THz power detector with on-chip antenna in 0.13μm SiGe HBT technology

Abstract This paper presents a broadband THz power detector with on-chip antenna implemented in 0.13μm SiGe HBT technology. The detector has a center frequency of 280 GHz, bandwidth of 64 GHz and responsivity of about 1 A/W. The nonlinear response of the power detector is analyzed and un-desirable linearization effects are discussed. High DC current gain and low-impedance base biasing are shown to improve the conversion gain, but the dominant gain-reducing effect is the feedback from the emitter resistance. The dynamic range and noise sources are also explained

Broadband characteristics of integrated Si lens antennas at 220–330 GHz

Abstract Directive, high-gain wireless links are needed to achieve practically feasible communications distances at sub-THz frequencies. This work investigates the operation of an integrated Si lens antenna that is fed by an on-chip antenna connected to a power detector, and the lens is working in receive mode. The antenna is studies using both simulations and over-the-air measurements. The simulated and measured results are in good agreement, and the proposed antenna design is a viable candidate for use in more advanced, higher functionality 6G applications