Large Antenna Research Articles

Dynamic Modeling of Liquid Crystal-Based Metasurfaces and Its Application to Reducing Reconfigurability Times

This paper describes and validates for the first time the dynamic modelling of Liquid Crystal (LC)-based planar multi-resonant cells, as well as its use as bias signals synthesis tool to improve their reconfigurability time. The dynamic LC director equation is solved in the longitudinal direction through the finite elements method, which provides the z- and time-dependent inhomogeneous permittivity tensor used in an electromagnetic simulator to evaluate the cells behaviour. The proposed model has been experimentally validated using reflective cells for phase control (reflectarray) and measuring the transient phase, both in excitation and relaxation regimes. It is shown how a very reduced number of stratified layers are needed to model the material inhomogeneity, and that even an homogeneous effective tensor can be used in most of the cases, which allows a model simplification suitable for design procedures without losing accuracy. Consequently, a novel bias signal design tool is proposed to significantly reduce the transition times of LC cells, and hence, of electrically large antennas composed of them. These tools, similar to those used in optical displays, are experimentally validated for the first time at mm- and sub-mm wave frequencies in this work, obtaining an improvement of orders of magnitude.

In Situ Space Plasma Diagnostics With Finite Amplitude Active Electric Experiments: Non‐Linear Plasma Effects and Instrumental Performance of Mutual Impedance Experiments

AbstractMutual impedance (MI) experiments are a kind of plasma diagnostic techniques for the identification of the in situ plasma density and electron temperature. These plasma parameters are retrieved from MI spectra, obtained by perturbing the plasma using a set of electric emitting antennas and, simultaneously, retrieving using a set of electric receiving antennas the electric fluctuations generated in the plasma. Typical MI experiments suppose a linear plasma response to the electric excitation of the instrument. In the case of practical space applications, this assumption is often broken: low temperature plasmas, which are usually encountered in ionized planetary environments (e.g., RPC‐MIP instrument onboard the Rosetta mission, RPWI/MIME experiment onboard the JUICE mission), force toward significant perturbations of the plasma dielectric. In this context, we investigate MI experiments relaxing, for the first time, the assumption of linear plasma perturbations: we quantify the impact of large antenna emission amplitudes on the (a) plasma density and (b) electron temperature diagnostic performance of MI instruments. We use electrostatic 1D‐1 V full kinetic Vlasov‐Poisson numerical simulations. First, we simulate the electric oscillations generated in the plasma by MI experiments. Second, we use typical MI data analysis techniques to compute the MI diagnostic performance in function of the emission amplitude and of the emitting‐receiving antennas distance. We find the plasma density and electron temperature identification processes robust (i.e., relative errors below 5% and 20%, respectively) to large amplitude emissions for antenna emission amplitudes corresponding to electric‐to‐thermal energy ratios up to .

Configuration synthesis and unfolding stiffness characteristics analysis of a truss antenna connecting mechanism based on URU-RR-URU hexagonal deployable unit

• A method of configuration synthesis of deployable connecting mechanism is proposed. • Simulation analysis method is used to determine the stiffness of the driving spring. • The motion principle of the modular mechanism based on URU-RR-URU unit is simulated. • Two deployable mechanisms are compared and discussed. • A prototype with high deployment rate is developed and experiments are conducted. The networking connection mechanism between deployable units is the key to realize large deployable antennas. Considering the RRR-RR-SRS and URU-RR-URU hexagonal deployable units, a method of configuration synthesis for deployable antenna connecting mechanism is proposed. First, according to the hexagonal and triangular combined units’ division of the parabolic reflector and based on screw theory, a method of configuration synthesis for connecting mechanism of a modular mechanism is proposed, and two modular mechanisms are obtained. Next, the motion principle of the modular mechanism, based on a spring actuation URU-RR-URU unit, is simulated, while simulation analysis method is used to determine the spring stiffness . The structure composition, motion characteristics and deployment rate of the two mechanisms are compared and analyzed. Finally, the modular deployable mechanism, able of complete folding, is selected, while the unit prototype and one-circle modular prototype are developed for validation experiments regarding the correctness of the presented theoretical analysis. The results provide a theoretical basis for the design and application of the supporting mechanism of large deployable antennas with high deployment rate.

Energy-Efficient Design of Broad Beams for Massive MIMO Systems

Massive MIMO is a promising air interface technology for 5G wireless communications. Such antenna systems offer capabilities to utilize channel correlations to create beams suitable for user specific transmissions. Most of the prior research is devoted to user-specific transmission in such systems, where a narrow beam is formed towards a user to improve its reception. Meanwhile, public-channel transmission to multiple users at once by means of broad beams has been understudied. In this paper, we introduce the concept of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">array-size invariant</i> (ASI) beamforming, enabling generation of broad beams from very large antenna arrays where all elements are transmitting at maximum power. The ASI technique offers the possibility to achieve a perfectly flat array factor by exploiting the additional degree of freedom coming from the dual-polarization beamforming. The proposed technique is applicable to both uniform linear and rectangular arrays. The benefits of the method are shown by means of several numerical examples. In particular, the practical usefulness of the ASI beamforming, in terms of coverage and energy efficiency, is illustrated on an example of designing a cell-specific broad beam for public-channel transmission in a realistic network deployment.

A new adaptive co-site broadband interference cancellation method with auxiliary channel

With the boom of the communication systems on some independent platforms (such as satellites, space stations, airplanes, and vessels), co-site interference is becoming prominent. The adaptive interference cancellation method has been adopted to solve the co-site interference problem. But the broadband interference cancellation performance of traditional Adaptive Co-site Interference Cancellation System (ACICS) with large delay mismatching and antenna sway is relatively poor. This study put forward an Adaptive Co-site Broadband Interference Cancellation System With Two Auxiliary Channels (ACBICS-2A). The system model was established, and the steady state weights and Interference Cancellation Ratio (ICR) were deduced by solving a time-varying differential equation. The relationship of ICR, system gain, modulation factor, interference signal bandwidth and delay mismatching degree was acquired through an in-depth analysis. Compared with traditional adaptive interference cancellation system, the proposed ACBICS-2A can improve broadband interference cancellation ability remarkably with large delay mismatching and antenna sway for the effect of auxiliary channel. The maximum improved ICR is more than 25 ​dB. Finally, the theoretical and simulation results were verified by experiments.

Performance of Cooperative Relay NOMA with Large Antenna Transmitters

The potential of the Non-Orthogonal Multiple Access (NOMA) approach for wireless communications in the fifth generation (5G) and beyond can not be underestimated. This is because users with favorable channel conditions can serve as relays to improve system performance by employing Successive Interference Cancellation (SIC). Lately, the combination of NOMA and the cooperative relay has attracted the interest of researchers. The analysis of cooperative relay NOMA (CR-NOMA) with a massive multiple-input multiple-output (mMIMO) system is mainly based on theoretical channel models such as the correlated-based stochastic channel model (CBSM) even though the geometric-based stochastic channel model (GBSM) has been found to provide better, practical and realistic channel properties. This, in our view, is due to computational challenges. Again, the performance of CR-NOMA systems using the GBSM channel model with large antenna transmitters and network coding schemes has attracted little attention in academia. Therefore, the need to study mMIMO CR-NOMA that considers channel properties such as path-loss, delay profile and tilt angle has become vital. Furthermore, the co-existing of large antenna transmitters with coding schemes needs further investigation. In this paper, we study the performance of a two-stage mMIMO CR-NOMA network where the transmitter is represented as a uniform rectangular array (URA) or cylindrical array (CA). The communication channel from the transmitter (TX) to the user equipment (UE) through a relay station (RS) is modeled with a 3GPP’s three-dimensional (3D) GBSM mMIMO channel model. To improve the analytical tractability of 3D GBSM, we defined the antenna element location vectors using the physical dimension of the antenna array and incorporated them into the 3D channel model. Bit-error rates, achievable rates and outage probabilities (OP) are examined using amplify-and-forward (AF) and decode-and-forward (DF) coding schemes. Results obtained show with fixed power allocation and SNR of 20 dB, far or weak users can attain a high achievable rate using DF and URA. Again, from the results, the combination of AF and CA presents better outage probabilities. Finally, the results indicate that the performance difference between CBSM and GBSM is marginal, even though the proposed 3D GBSM channel model has a higher degree of random parameters and computational complexities.

ELAA Channel Characterization with Parameter Estimation Based on a Generalized Array Manifold Model

The extremely large antenna arrays (ELAAs) and millimeter-wave systems have become key techniques for obtaining higher frequency spectrum efficiency in sixth-generation (6G) communication systems. It is necessary to determine appropriate statistical models to describe the channel characteristics for the ELAAs, such as spatial non-stationarity, dispersion in angular domain, and spatial consistency. Thus, a signal model based on the generalized array manifold (GAM) that describes the dispersion in direction using the definition of the slightly distributed scatterer (SDS) is proposed in this work. An estimator for the parameters of the GAM model, namely GAM Space-Alternating Generalized Expectation-maximization (GAM-SAGE), is also designed. Moreover, a method to obtain a stochastic SDS-based channel model (SBCM) that is capable of reproducing the spatial consistency is proposed. The method is then used to establish measurement-based models for line-of-sight (LoS) and non-line-of-sight (NLoS) scenarios using a 40×40 receiver (Rx) planar antenna array at a carrier frequency of 40 GHz. The results demonstrate that the SBCM is capable of achieving spatially consistent results and outperforms the specular-path (SP) models in completely characterizing the ELAA channels at millimeter-wave bands, which are fundamental for the design of 6G.

Electrically large aperture horn array antenna with low side lobe level for Ku‐band frequency

AbstractUsing electrically large antennas for array applications may cause grating lobes and this can change the array pattern. To achieve a low side lobe level for boresight pattern for linear or planar array antennas, in the literature it is seen that the common method is the use of feeding each antenna with some amplitude distribution and keeping the distance between the antennas less than a wavelength. However, in this study the distance between the antennas is chosen to be greater than a wavelength. Therefore, the common methods cannot be used. To achieve a low side lob level in the radiation pattern for an array of antennas composed of antennas with a distance greater than one wavelength. The aperture length of each antenna is chosen to be variable and an analytical solution method is used to calculate the amplitude of each aperture field of the horn antennas. Thus, the determination of unit horns' optimal aperture lengths Li can be considered a multivariable optimization problem. This challenging problem was achieved using a novel meta‐heuristic optimization algorithm called the differential evolutionary algorithm (DEA), where the aperture lengths of each array element are taken as inputs to find the optimal side lobe level (SLL). Based on the obtained solutions, a 4 × 1 horn array antenna design alongside its feed network was designed for Ku‐band applications. The design of the array is simulated in CST simulation software, and the obtained simulated results had been compared with experimental results and counterpart designs in the literature.

Integrated sensing and communication in 6G: a prototype of high resolution multichannel THz sensing on portable device

6G is believed to go beyond communication and provide integrated sensing and computing capabilities for a vision of Connected Intelligence with everything connected, everything sensed, and everything intelligent. Integrated sensing and communication will play a vital role for the fusion of physical and cyber worlds. The exploration of higher frequency bands, larger bandwidth, and more advanced large antenna technologies is paving the way towards the goal. In particular, the study of THz opens the possibility to have high resolution sensing and imaging capability on a communication mobile device. In this paper, we take a step along this direction and justify such possibility by building a THz sensing prototype with millimeter level imaging resolution while considering the physical aperture constraint of typical mobile device.

Attitude control actuator scaling laws for orbiting solar reflectors

The rapid evolution of in-orbit manufacturing will enable the fabrication of low-cost, large-scale space structures. In particular, the use of 3D printing technologies will remove traditional payload constraints associated with launch vehicles, due to fairing size and launch loads, thus allowing the construction of larger and lighter structures, such as orbiting solar reflectors. These structures will require efficient attitude control systems, able to provide the necessary torque for maneuvers and to counteract perturbations, such as gravity gradient and solar radiation pressure. In this paper, a top-level overview of actuator performances for orbiting solar reflectors is provided, and scaling laws associated with the required actuator mass and input power are developed. For each class of actuator, upper bounds on the maximum size of the structure which can be effectively controlled are presented. The results can also be extended to other classes of large planar Earth-pointing structures such as solar power satellites, solar sails, or large antennae.

Electrical Property of 3D Printed Continuous Fiber Reinforced Thermoplastic Composite Mesh Reflecting Surfaces

Continuous fiber reinforced thermoplastic composites have been widely used in modern aerospace and other high-end manufacturing fields because of their light weight, high strength, fatigue resistance, and corrosion resistance properties. Due to the reinforcement of carbon fiber strands, continuous fiber reinforced thermoplastic composites have good conductivity which makes it a potential material for the preparation of space-borne antennas reflecting surfaces. The reflecting surfaces of common mesh antennas are usually prepared by gold-plated molybdenum wire which is expensive and hard to produce. In this study, the continuous fiber reinforced thermoplastic composites mesh reflecting surfaces are prepared by 3D printing technology. The effect of different mesh shape and mesh size on the electrical properties are investigated systematically. The electrical property of the reflecting surface were tested by waveguide method at the S band with the frequency of 1.9 ~ 2.3GHz. The results show that the reflection loss of the 3D printed continuous fiber reinforced thermoplastic composite mesh reflecting surfaces are lower than 0.25 dB, which can well meet the requirement of space-borne antennas in the S waveband. The reflection loss of the 3D printed continuous fiber reinforced thermoplastic composite mesh reflecting surfaces increases with the increase of mesh size accordingly for both the quadrangular and the triangular mesh reflecting surface. The reflecting property of the mesh reflecting surface tends to be better with a higher surface mass density. The results foresee that the continuous fiber reinforced thermoplastic composites can be used to develop the reflector of large mesh antenna in the future work.

Design and Analysis of a New Deployable Docking Mechanism for Microsatellites

In-orbit docking technology of microsatellites to realize combined reconfiguration has a wide application prospect, such as large antennas and space telescopes. In order to reduce collision impact and improve docking accuracy, a new deployable docking mechanism is proposed based on the slider-crank principle, which has the advantages of smaller volume and larger posture tolerance. To achieve large capture tolerance and increase the success rate of docking, the posture error is analyzed by considering the specific boundary of the position and pose. And a step-by-step cooperative capture strategy is proposed to complete the velocity selection and action matching among multiple capture arms. The reliable docking of posture correction in the docking process is realized by designing the action path of the docking mechanism. The effects of tolerance capture under different initial posture conditions are analyzed by dynamic simulation. The effectiveness and superiority of the step-by-step cooperative capture strategy are valid by comparison with the synchronized capture strategy. The comparison results show that the impact force is reduced by 8% than the synchronized strategy. The capture experiments are carried out to verify the docking performance. The results show the proposed configuration with a step-by-step cooperative capture strategy achieves successfully reliable capture, weak impact, and large posture tolerance under eight extreme initial pose conditions.

An Inhomogeneous Plane-Wave Based Single-Level Fast Direct Solver for the Scattering Analysis of Extremely Large Antenna Arrays

A semianalytic single-level fast direct solver (FDS) is presented for the method-of-moments (MoM) analysis of large planar antenna arrays with up to few thousands of complex elements on current desktop computers. Assuming a partition of the impedance matrix, the proposed scheme factorizes the near-field blocks via a singular value decomposition (SVD)-based low-rank approximation and the intermediate-field blocks via an analytical inhomogeneous plane-wave (IPW) expansion. The near- and intermediate-field bases are then unified to leverage the Woodbury formula for the inversion. The solutions for the excitation of each array ports are obtained at once with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$O(N^{15/7} \ln ^{3} N)$ </tex-math></inline-formula> computational cost and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$O(N^{11/7} \ln N)$ </tex-math></inline-formula> memory for array problems with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> basis functions. The complexities are traced precisely and the error is controlled by means of analytical formulas for the required number of IPWs. The FDS is also combined with a macrobasis function (MBF) approach to deal with antenna geometries containing many subwavelength details. This article includes simulations of regular arrays of about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$169^{2}~3$ </tex-math></inline-formula> -D dipoles and an irregular array composed of seven stations of the low-frequency square kilometer array (SKA) telescope comprising each 256 log-periodic (LP) antennas. The proposed FDS allows the analysis of the coupling effect both within any one station but also between the stations of the telescope, a size and complexity of problem which has not been possible with existing published techniques.

Design of Electrically Large UHF RFID Near-Field Bidirectional Antenna With AMC-Based Unidirectional Improvement

Two novel multisegment loops coupled ultrahigh-frequency (UHF) radio frequency identification near-field (NF) antenna with a uniform and strong magnetic field distribution over an electrically large interrogation zone are designed. Each proposed antenna is composed of eight loops, and the current distribution along the loop is kept in-phase using a segmented line. To further achieve a more uniform magnetic field, the last four loops of the two proposed antennas (ANT 1 and ANT 2) are loaded with parasitic structures. Here, a 100% detection rate is achieved by ANT 1 within an interrogation area of 370×560×105 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> for the bidirectional operation setup. As for ANT2, it is backed by an artificial magnetic conductor to enhance the magnetic field strength and reduce the profile with respect to a configuration with a PEC reflector plane, and it has yielded a 100% detection rate within the interrogation area of 370×560×185 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> for the unidirectional operation setup. The proposed ANT2 can cover the UHF band of China, the Federal Communications Commission band of North America, and European Telecommunication Standards Institute band of Europe.

Massive MIMO Empowered Wireless Powered Sensor Networks: An Optimal Design With Statistical CSI

Wireless energy transfer (WET) has been anticipated as a viable solution to combat the challenges of scarce energy supply in Internet-of-Things (IoT) applications. To reap the benefit brought by large scale antenna arrays, massive multiple-input-multiple-out (MIMO) empowered wireless powered sensor networks (WPSNs) is investigated in this letter to meet the urgent demand for reliable and self-sustainable IoT applications. Considering a large-scale antenna array deployed at the access point for energy transfer to and information collection from the multiple-antenna wireless powered sensors, the hardening property in energy transfer is generalized and theoretically proved based on random matrix theory. Based on the hardening properties, the harvesting energy and the uplink sum-rate for sensor data collection are found to be asymptotically deterministic and depend on the statistical channel state information (CSI) only. The hardening properties in both energy and information transfers enable a novel optimal design on the WPSNs based on statistical CSI only. Particularly, the designs of the downlink energy beamforming and multiple uplink information beamforming can be decoupled, and global optimal solutions for the beamforming and time allocation to maximize the uplink sum-rate given downlink power constraint are found in semi-closed forms. Different from prior WPSNs designs, statistical CSI but not instantaneous CSI is exploited and frequent channel estimation and heavy communication overhead can be avoided with a much lower computation complexity, thus improving the practicability and sustainability of the WPSNs. The effectiveness of the proposed design is finally demonstrated by numerical simulations.

Recent Advances in Space-Deployable Structures in China

Deployable space structure technology is an approach used in building spacecraft, especially when realizing deployment and folding functions. Once in orbit, the structures are released from the fairing, deployed, and positioned. With the development of communication, remote-sensing, and navigation satellites, space-deployable structures have become cutting-edge research topics in space science and technology. This paper summarizes the current research status and development trend of space-deployable structures in China, including large space mesh antennas, space solar arrays, and deployable structures and mechanisms for deep-space exploration. Critical technologies of space-deployable structures are addressed from the perspectives of deployable mechanisms, cable-membrane form-finding, dynamic analysis, reliable environmental adaptability analysis, and validation. Finally, future technology developments and trends are elucidated in the fields of mesh antennas, solar arrays, deployable mechanisms, and on-orbit adjustment, assembly, and construction.

Statistical CSI-Based Design for RIS-Assisted Communication Systems

Reconfigurable intelligent surfaces (RISs) have attracted considerable attention over the past years. A RIS can smartly adjust the phase of incident wavefronts and create anomalous reflections towards desired directions. In this letter, we consider a RIS-assisted large antenna system and investigate the ergodic spectral efficiency (SE). By considering a finite dimensional channel, we derive an upper bound on the ergodic SE. Based on this upper bound, we propose an optimal phase shift design by exploiting statistical channel state information. Specifically, we develop a semidefinite relaxation technique and Gaussian randomization procedure for continous phase shift design. Furthermore, an alternating optimization algorithm is applied to the discrete case. Numerical results verify the tightness of the upper bound and the effectiveness of our phase shift design. Considering hardware limitations, we find that a RIS of 2-bit phase adjustable elements achieves the same ergodic SE as the continous phase shift architecture.

Index Modulation Pattern Design for Non-Orthogonal Multicarrier Signal Waveforms

Spectral efficiency improvement is a key focus in most wireless communication systems and achieved by various means such as using large antenna arrays and/or advanced modulation schemes and signal formats. This work proposes to further improve spectral efficiency through combining non-orthogonal spectrally efficient frequency division multiplexing (SEFDM) systems with index modulation (IM), which can efficiently make use of the indices of activated subcarriers as communication information. Recent research has verified that IM may be used with SEFDM to alleviate inter-carrier interference (ICI) and improve error performance. This work proposes new SEFDM signal formats based on novel activation pattern designs, which limit the locations of activated subcarriers and enable a variable number of activated subcarriers in each SEFDM subblock. SEFDM-IM system designs are developed by jointly considering activation patterns, modulation schemes and signal waveform formats, with a set of solutions evaluated under different spectral efficiency scenarios. Detailed modelling of coded systems and simulation studies reveal that the proposed designs not only lead to better bit error rate (BER) but also lower peak-to-average power ratio (PAPR) and reduced computational complexity relative to other reported index-modulated systems.

Networking Method for the Structure of a Large Modular Deployable Space Antenna

A high-precision networking method for a modular deployable antenna with ultramultiple modules is proposed to solve the problem of achieving an accurate formation of the structure of a large-aperture modular deployable space antenna. In accordance with the general requirements for the deployment surface of deployable antennas, the structure composition and deployment principle of a deployable antenna are analyzed, and the topological law of a hexagonal prism modular structure is expounded. On the basis of basic theories of differential geometry, analytical geometry, and robotics, the mathematical model of an envelope circle and that of its center are established. Then, a networking model of structure that includes 61 modules in the fully deployed state is established. Finally, the established model is verified via a numerical simulation method, and the influence law of structural parameters on networking characteristics is analyzed and studied. Simulation results show that the networking method can realize an accurate connection of multiple modules. The networking method for the structure of a modular deployable antenna proposed in this study can provide a reference for research on basic theory of a deployable antenna’s mechanism and related engineering applications.

Community‐wide trait adaptation, but not plasticity, explains ant community structure in extreme environments

Abstract Quantifying trait–environment associations can help elucidate the processes underpinning the structure of species assemblages. However, most work has focused on trait variation across rather than within species, meaning that processes operating at the intraspecific levels cannot be detected. Incorporating intraspecific trait variation in community‐wide analyses can provide valuable insights about the role of morphological adaptation and plasticity on species persistence and the composition of ecological communities. Here, we assessed geographical variation in the direction (i.e. adaptation) and strength of selection, and the magnitude of plasticity, by examining community‐wide trait variation in ant communities along an environmental gradient spanning 9° latitude in Quebec, Canada. Specifically, we measured 9 morphological traits related to foraging strategies, resource use and thermal regulation at 20 locations across temperate and boreal forests. We then examined how the mean and variance of these traits varied along temperature and precipitation gradients. Moreover, we examined how these trait–environment relationships varied across levels of organization, from individual workers (intraspecific) to colonies (intraspecific) and species (interspecific). We observed changes in mean trait values along environmental gradients, but very little change in variance. Specifically, we observed a decrease in the mean length of antennae and an increase in the mean eye length from mild (warm and wet) to more extreme environments (cold and dry). These shifts in trait means were mostly coordinated across organizational levels (i.e. worker, colony and species). We also observed a general increase in trait variance from mild to extreme environments, but only at the species level. Our findings suggest that stressful environmental conditions exert a strong selection pressure on ant morphology causing shifts in optimal trait values. These adaptations may enable persistence at the northern edge of the boreal forest and therefore influence the composition of these ant communities. Specifically, ants with large eyes and short antennae are overrepresented at the transition zone between the boreal forest and the tundra, possibly representing an adaptation to these more open habitats. Our study demonstrates that combining spatial and community‐wide intraspecific functional trait data provides a promising way forward to gain new insights on trait adaptations and processes underpinning community structure along environmental gradients. Read the free Plain Language Summary for this article on the Journal blog.