Recent Advancements in Millimeter-Wave Antennas and Arrays: From Compact Wearable Designs to Beam-Steering Technologies
Abstract
1. Introduction
1.1. Background and Significance
1.2. Evolution of mmWave Antennas and Arrays
1.3. Challenges in mmWave Antenna Design
- High signal loss: mmWave signals become weak due to air, obstacles, and absorption.
- Weak penetration: they have limited penetration through obstacles such as walls, foliage, and the human body.
- Miniaturization: designing efficient antennas for compact devices is challenging.
- Heat issues: high frequencies can cause heating.
- Material limits: regular materials do not work well; new ones are needed.
1.4. Applications of mmWave Antennas
- 5G and 6G networks: mmWave technology enables high-speed wireless communication, offering faster data transfer, reduced latency, and better efficiency [7].
- Wearable and body-centric antennas: compact and flexible mmWave antennas support advancements in wearable electronics, smart textiles, and health monitoring devices [8].
- Autonomous vehicles and UAV communication: mmWave antennas are crucial for vehicle-to-everything (V2X) communication, allowing real-time data exchange for navigation and collision avoidance [9].
- Radar and remote sensing: mmWave radar systems are used for precise object detection and environmental sensing in defense, weather monitoring, and industrial applications [10].
2. Methodology
2.1. Databases Searched
2.1.1. IEEE Xplore
2.1.2. Scopus
2.1.3. Web of Science
2.2. Search Strategy and Keywords
Keyword Selection
- mmWave antennas;
- Phased array antennas;
- Millimeter wave communication;
- Beamforming techniques;
- 5G and 6G antenna design;
- High-frequency antenna arrays.
- AND (e.g., mmWave AND phased arrays) to narrow results by combining related topics.
- OR (e.g., millimeter wave OR mmWave) to include different terms and synonyms.
2.3. Inclusion and Exclusion Criteria
- Peer-reviewed journal articles or conference papers.
- Studies published between 2000 and 2025.
- Articles focused on the design, analysis, fabrication, or application of mmWave antennas, phased arrays, or beamforming techniques.
- Papers that address performance evaluation, challenges, or future trends in mmWave communication and antenna systems.
- Non-English articles.
- Editorials, opinion, and non-peer-reviewed papers.
- Studies that focus only on theoretical models without experimental validation.
- Duplicate studies or articles lacking full-text access.
2.4. Data Extraction and Analysis
- Study details: Author(s), publication year, and source (journal/conference).
- Objective: The aim and scope of the study.
- Methodology: Study design and experimental setup.
- Findings: Major contributions and results.
- Discussion: Gaps identified in the study.
3. Antenna Design and Optimization Techniques
3.1. Beamforming and Beam-Steering Techniques
3.2. MIMO Antennas and Array Architectures
- Planar Arrays: Most common in mmWave applications due to compactness and ease of fabrication.
- Cylindrical and Spherical Arrays: Provide 360° coverage and are often used in mobile or drone-based platforms.
- Massive MIMO: Employs large-scale arrays with hundreds of elements to improve beamforming granularity and reduce interference.
3.3. Compact and Wearable Antennas
- Flexible substrates: use of polymers like PDMS, Kapton, and Rogers materials for stretchability and bendability [56].
- E-textiles: integration of conductive threads into clothing to form body-worn antenna arrays [57].
- Fractal geometries: space-filling curves that provide multiband operation in a compact footprint [58].
- Implantable antennas: developed for biomedical telemetry at mmWave frequencies [59].
4. Materials, Fabrication, and Integration Technologies
4.1. Advanced Materials for mmWave Antennas
4.2. Fabrication Techniques and Challenges
4.3. Integration with Devices and Systems
4.4. Performance Evaluation Metrics
- Return loss (S11): Measures the amount of power reflected back from the antenna input. A lower return loss (e.g., less than −10 dB) indicates better impedance matching and efficient power transfer.
- Gain: Represents the antenna’s ability to direct radiated power in a specific direction, typically expressed in decibels relative to an isotropic radiator (dBi). Higher-gain antennas provide improved signal strength and range.
- Radiation efficiency: The ratio of power radiated by the antenna to the power supplied to it. High efficiency minimizes losses due to materials and fabrication.
- Bandwidth: the frequency range over which the antenna maintains acceptable performance, often defined by return loss or gain criteria.
- Isolation (for MIMO systems): describes the degree of decoupling between antenna elements, critical for reducing mutual interference and improving system capacity.
- Specific absorption rate (SAR): important for wearable antennas, SAR quantifies the rate at which human tissue absorbs electromagnetic energy, necessitating designs that minimize exposure.
- Beamforming accuracy: for phased arrays and beam-steering antennas, the precision of beam direction and shape affects system performance in dynamic environments.
5. Applications of mmWave Antennas
5.1. Wireless Communication (5G and 6G Networks)
5.2. Wearable and Body-Centric Applications
5.3. Automotive Radar and V2X Communication
5.4. UAV and Satellite Communication
5.5. Imaging and Sensing Technologies
5.6. Biomedical Imaging and Health Monitoring
5.7. Environmental and Industrial Sensing
6. Discussion and Future Directions
Limitations and Trade-Offs in Current mmWave Antenna Technologies
7. Conclusions
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Title | Aim of Paper | Research Findings | Conclusion |
---|---|---|---|
Compact UWB MIMO Antenna for 5G Millimeter-Wave Applications [13] | Design a compact ultra-wideband MIMO antenna for 5G mmWave applications. | Proposed a compact UWB MIMO antenna with high isolation and wide bandwidth suitable for 5G applications. | Demonstrated the feasibility of compact MIMO antennas for high-speed 5G communications. |
A Survey on Millimeter-Wave Beamforming Enabled UAV Communications and Networking [14] | Provide a comprehensive survey on mmWave beamforming for UAV communications. | Reviewed mmWave antenna structures, channel modeling, and beamforming techniques for UAVs. | Identified challenges and future research directions in mmWave UAV communications. |
Overview of Millimeter Wave Communications for Fifth-Generation (5G) Wireless Networks [15] | Overview of mmWave communications with a focus on propagation models for 5G. | Compared propagation parameters and channel models over 0.5–100 GHz range. | Highlighted the importance of accurate channel models for mmWave 5G deployment. |
A Miniaturized Antenna for Millimeter-Wave 5G-II Band Communication [16] | Design a miniaturized antenna for 5G-II band communication. | Developed a compact antenna with improved gain and bandwidth for 5G-II band. | Validated the antenna’s suitability for compact 5G devices. |
A Comprehensive Review on Millimeter Waves Applications and Antennas [17] | Review mmWave applications and antenna designs. | Discussed various mmWave antenna models and their applications in high-speed data transmission. | Emphasized the potential of mmWave technology in future communication systems. |
Hybrid Beamforming for 5G and Beyond Millimeter-Wave Systems: A Holistic View [18] | Present a holistic view on hybrid beamforming for 5G mmWave systems. | Compared different hardware structures and beamforming algorithms for efficiency and performance. | Identified promising hybrid beamforming techniques for future wireless networks. |
Ultra-wideband Antenna System Design for Future mmWave Applications [19] | Design an ultra-wideband antenna system for future mmWave applications. | Proposed an antenna system with enhanced bandwidth and gain for mmWave applications. | Demonstrated the system’s potential for next-generation wireless communications. |
Millimeter Wave Sensing: A Review of Application Pipelines and Building Blocks [20] | Review mmWave sensing applications and building blocks. | Analyzed hardware, algorithms, and models for mmWave sensing applications. | Provided insights into the development of mmWave sensing technologies. |
Metamaterial Inspired Millimeter-Wave Antenna Arrays for 5G Wireless Applications [21] | Design metamaterial-inspired mmWave antenna arrays for 5G. | Developed single and array antenna designs with improved performance using metamaterials. | Showed the effectiveness of metamaterials in enhancing antenna performance. |
Five-Band Millimeter-Wave Antenna of Circular/Linear Polarization for Forthcoming Generations of Mobile Handsets [22] | Develop a five-band mmWave antenna with circular/linear polarization for mobile handsets. | Designed an antenna supporting multiple bands with dual polarization for enhanced performance. | Validated the antenna’s applicability for future mobile handsets. |
Performance improvement of millimeter wave antennas (review) [23] | Review performance improvement techniques for mmWave antennas. | Discussed various methods to enhance bandwidth, gain, and efficiency of mmWave antennas. | Provided a comprehensive overview of performance enhancement strategies. |
Design of a Compact Millimeter Wave Antenna for 5G Applications based on Meta Surface Luneburg Lens [24] | Design a compact mmWave antenna using a metasurface Luneburg lens for 5G. | Proposed an antenna design with improved directivity and compactness using metasurface lens. | Demonstrated the design’s potential for 5G applications. |
Review on Millimeter Wave Antennas- Potential Candidate for 5G Enabled Applications [25] | Review mmWave antennas as potential candidates for 5G applications. | Analyzed various mmWave antenna designs and their suitability for 5G. | Highlighted the importance of mmWave antennas in 5G networks. |
Millimeter wave antenna with enhanced bandwidth for 5G wireless application [26] | Design a mmWave antenna with enhanced bandwidth for 5G applications. | Developed an antenna with improved bandwidth and stable radiation patterns at 28 GHz. | Validated the antenna’s performance for 5G applications. |
High Performance 5G FR-2 Millimeter-Wave Antenna Array for Point-to-Point and Point-to-Multipoint Operation [27] | Design high-performance mmWave antenna arrays for 5G FR-2 band. | Developed 8-element linear and 32-element planar arrays with high gain and beamwidth control. | Demonstrated the arrays’ suitability for various 5G applications. |
Antenna Design for Microwave and Millimeter Wave Applications II: Latest Advances and Prospects [28] | Review latest advances in antenna design for microwave and mmWave applications. | Summarized recent developments in antenna miniaturization, optimization, and array configurations. | Provided insights into future prospects of antenna design. |
Design of multiband MIMO antenna for 5G millimeterwave application [29] | Design a multiband MIMO antenna for 5G mmWave applications. | Proposed a multiband MIMO antenna with improved isolation and bandwidth. | Demonstrated the antenna’s effectiveness for 5G applications. |
MIMO antenna array for mm-wave 5G smart devices [30] | Develop a MIMO antenna array for mmWave 5G smart devices. | Designed a compact MIMO antenna array with enhanced performance for smart devices. | Validated the design’s applicability for 5G smart devices. |
A dual-polarized cavity-backed aperture antenna for 5G mmW MIMO applications [31] | Design a dual-polarized cavity-backed aperture antenna for 5G mmWave MIMO applications. | Developed an antenna with improved isolation and bandwidth for MIMO systems. | Demonstrated the antenna’s suitability for 5G MIMO applications. |
Multiband microstrip patch antenna for 5G wireless applications using MIMO techniques [32] | Design a multiband microstrip patch antenna for 5G using MIMO techniques. | Proposed an antenna with multiple bands and improved performance for 5G MIMO systems. | Validated the antenna’s effectiveness for 5G applications. |
mmWall: Steerable Transflective Metamaterial Surface [33] | Real-time indoor beam relay through walls | Demonstrated full 360° steering with 91% outage-free coverage; SNR boost up to 30 dB | Programmable metasurface provides robust mmWave coverage |
High-Gain Metasurface Lens Antenna for mmWave Radar [34] | Design of lens-integrated metasurface antenna | Achieved >15 dBi gain and narrow beams using metasurface lens element | Compact, high-gain mmWave radar antenna enabled |
Hybrid Antenna–Metasurface Architecture for mmWave/THz MIMO [35] | Integrate passive metasurface with active MIMO array | Achieved steerable pencil beams, reduced RF chain counts | Hybrid arrays improve efficiency and reduce complexity |
High-Gain Metasurface-Integrated Planar Antenna [36] | Enhance planar antenna via metasurface reflector | Measured ∼9 dBi gain across 23–39 GHz bandwidth | Reflector metasurface significantly boosts gain and bandwidth |
Metasurface Filter Antenna Array with Ridge-Gap Waveguide [37] | Improve beam steering and filtering via metasurface + RGW | Achieved dual-polarized wideband performance, low sidelobes | Compact high-performance filter-array design |
Metasurface Antenna for 28 GHz RoF [38] | Enhance gain and EVM in radio-over-fiber link | Gain improved, EVM reduced from 3.7% to 2.7% using superstrate | Metasurface superstrate effectively boosts RoF link performance |
Deep Learning Coordinated Beamforming [39] | ML-assisted beamforming for mobile mmWave links | Approaches genie-aided beam selection, reduces training overhead | AI methods enable efficient beamforming |
IRS-Assisted mmWave Communication [40] | Joint EP + active precoding with intelligent reflecting surfaces | Quadratic gain scaling with number of reflectors, robust to blockage | IRSs offer effective blockage mitigation |
Smart Surface-Enabled 5G mmWave Networking [41] | Programmable roadside metasurfaces for mmWave relays | Achieved robust coverage with real-time beam control | Low-power metasurface aids pervasive urban mmWave |
Dynamic Metasurface Antennas for Uplink Massive MIMO [42] | Realize uplink MIMO with dynamic metasurface antenna arrays | Achieved adaptive beam patterns with few-bit control | D-MIMO arrays present energy-efficient massive MIMO solution |
A Reconfigurable Metasurface for Beam Steering in 5G mmWave Systems [43] | To design and experimentally validate a metasurface-based antenna capable of dynamic beam steering for 5G mmWave applications. | The proposed metasurface demonstrated rapid beam steering over ±30° with high gain (15 dBi) and low sidelobe levels, verified through full-wave simulation and prototype measurements. | The metasurface antenna offers a compact, efficient solution for next-generation mmWave beamforming, improving link reliability in dynamic environments. |
AI-Driven Topology Optimization of mmWave Antennas Using Deep Learning [44] | To develop a deep learning framework for automatic design and optimization of mmWave antennas with complex topologies. | The AI approach accelerated design cycles by 80% and produced antenna layouts with enhanced impedance bandwidth and gain, validated by simulations and fabricated prototypes. | Deep learning enables efficient exploration of large design spaces, pushing the limits of antenna performance and manufacturability. |
Quantum Metasurface Antennas for Enhanced Wireless Communications [45] | To explore the integration of quantum materials with metasurface antennas to enhance signal coherence and reduce noise at mmWave frequencies. | Experimental results showed improved signal-to-noise ratio and coherence times due to quantum material properties, supported by theoretical modeling. | Quantum metasurfaces present a promising path for ultra-low noise mmWave communication systems, with potential impact on secure and high-capacity links. |
Type | Key Characteristics | Use Cases | Typical Data Rate | Pros and Cons |
---|---|---|---|---|
Analog Beamforming [47] | RF-phase-shifter based single-beam steering | IoT devices, low-power mmWave links | Up to 1 Gbps | + Low power, low cost |
- Limited flexibility, supports only one beam | ||||
Digital Beamforming [48] | Digital baseband control for multiple beams and MIMO support | Massive MIMO, adaptive radar, SDRs | Up to 10 Gbps | + High flexibility, ideal for dynamic environments |
- Expensive, high power consumption | ||||
Hybrid Beamforming [49] | Combines analog and digital control for multiple streams with fewer RF chains | 5G NR base stations, mmWave backhaul | 5–10 Gbps (depending on streams) | + Trade-off between performance and cost |
- Moderate complexity, harder calibration |
MIMO Array Type | Structure | Coverage Pattern | Typical Gain (dBi) | Isolation (dB) | Use Cases |
---|---|---|---|---|---|
Planar [52] | Two-dimensional flat surface | Narrow/sector-based (up to 120°) | 6–9 dBi | 15–20 dB | Best suited for smartphones and handheld devices due to ease of integration and low-profile form factor. Limited coverage unless multiple arrays are used. |
Cylindrical [53] | Curved around cylinder or body | Omnidirectional, 360° azimuth | 8–12 dBi | 18–25 dB | Ideal for mobile platforms such as UAVs and vehicle-mounted systems. Provides nearly full azimuthal coverage with moderate complexity. |
Massive MIMO [54] | Large-scale planar or 3D grids | Highly directional, narrow beams with high spatial resolution | 15–25 dBi (array gain) | >25 dB | Used in 5G/6G macro base stations. Offers significant spectral efficiency, beam steering, and spatial multiplexing for dense urban environments. Requires extensive calibration and computational resources. |
Fabrication Method | Resolution/Precision | Scalability and Cost | Strengths and Limitations |
---|---|---|---|
PCB Etching | ∼100 μm | High scalability, low cost | Standard, but limited for 3D/conformal shapes |
Inkjet Printing | ∼50–100 μm | Limited throughput, moderate cost | Suitable for flexible substrates; durability and uniformity concerns |
Aerosol Jet Printing | <50 μm | Moderate scalability, high cost | High resolution; useful for complex geometries |
LDS (Laser Direct Structuring) | ∼100 μm | Medium scalability, high initial cost | Conformal 3D patterning; dependent on special polymers |
Photolithography | <10 μm | Low scalability, very high cost | High precision; ideal for MMICs, not flexible or low-cost |
Features | Benefits |
---|---|
High bandwidth | Gigabit data rates. |
Compact array integration | Small cell and user terminal support. |
Beamforming/MIMO capabilities | Enhanced spectral and energy efficiency. |
Platform | Use Case | Frequency Bands |
---|---|---|
UAVs [81] | Real-time surveillance, control | 28 GHz, 60 GHz |
Satellites [82] | Earth observation, broadband delivery | 30 GHz (Ka-band) |
Sector | Application | Advantage |
---|---|---|
Healthcare [83] | Tumor detection, skin diagnostics | High spatial resolution |
Security [84] | Concealed object detection | Non-ionizing, safe scanning |
Industrial [85] | Material defect inspection | Penetration through surfaces |
Use Case | Antenna Design Requirements | Application Type |
---|---|---|
Skin/breast cancer detection | High resolution, non-ionizing, accurate tissue characterization | Imaging |
Vital sign monitoring (respiration, heartbeat) | Doppler sensing, real-time monitoring, integration into fabrics | Wearable sensing |
Wireless implant communications | Miniaturized, biocompatible, low-SAR | Biomedical telemetry |
Use Case | Antenna Design Requirements | Application Type |
---|---|---|
Pipe crack detection and fluid-level sensing | Durable, radar-optimized, high accuracy in harsh conditions | Industrial monitoring |
UAV-based air quality monitoring | Lightweight, wide-area coverage, low power | Environmental sensing |
Soil moisture and smart agriculture sensors | Weather-resistant, compact form, IoT-compatible | Precision agriculture |
Area | Current Status | Future Directions and Research Questions |
---|---|---|
Antenna Miniaturization | Performance–size trade-offs using conventional planar designs | Use fractal or metasurface-based geometries optimized via machine learning. Research Q: How can evolutionary algorithms optimize compact mmWave antennas while maintaining multiband and wideband performance? |
Beamforming and Steering | Analog/digital/hybrid systems with limitations in power and latency | Apply deep reinforcement learning for adaptive beam control in dynamic environments. Research Q: How can DRL be used for real-time beam selection in UAV networks under mmWave conditions? |
Materials | Limited to static or linear dielectric materials | Develop tunable and biocompatible materials such as graphene, LCP, and phase-change materials. Research Q: Can liquid-metal-based substrates provide self-healing and tunable radiation behavior? |
Fabrication Techniques | 2D PCB and limited 3D/inkjet methods | Combine inkjet, laser, and roll-to-roll processes for flexible, multilayer antenna structures. Research Q: How can multimaterial additive manufacturing be used to produce wearable mmWave antennas with conformal curvature? |
Application Expansion | 5G/6G, radar, imaging, wearables | Explore sub-THz systems, quantum networks, and integrated sensing. Research Q1: How can mmWave antennas be co-designed with quantum components for secure, cryogenic communications? Research Q2: What are the trade-offs when integrating sensing and communication within a shared mmWave platform? |
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Mehmood, F.; Mehmood, A. Recent Advancements in Millimeter-Wave Antennas and Arrays: From Compact Wearable Designs to Beam-Steering Technologies. Electronics 2025, 14, 2705. https://doi.org/10.3390/electronics14132705
Mehmood F, Mehmood A. Recent Advancements in Millimeter-Wave Antennas and Arrays: From Compact Wearable Designs to Beam-Steering Technologies. Electronics. 2025; 14(13):2705. https://doi.org/10.3390/electronics14132705
Chicago/Turabian StyleMehmood, Faisal, and Asif Mehmood. 2025. "Recent Advancements in Millimeter-Wave Antennas and Arrays: From Compact Wearable Designs to Beam-Steering Technologies" Electronics 14, no. 13: 2705. https://doi.org/10.3390/electronics14132705
APA StyleMehmood, F., & Mehmood, A. (2025). Recent Advancements in Millimeter-Wave Antennas and Arrays: From Compact Wearable Designs to Beam-Steering Technologies. Electronics, 14(13), 2705. https://doi.org/10.3390/electronics14132705