Antenna Systems Group

The EmRG Antenna Systems Group researches advanced beamforming and massive MIMO systems for satellite and 5G/6G communications. Our work focuses on PCB-based active phased-array antennas, digital beamforming massive MIMO systems, 3D-printed antenna systems, passive antenna arrays, packaging and system integration, and electrothermal-mechanical co-design techniques.

Rendering of a modular large-scale active phased array antenna for SATCOM with heatsink

Prototypes

Antennas, arrays and calibration methods designed and measured in the group, from 27 GHz through to the FR3 band.

Exploded rendering of the near-field probing array showing the beamformer IC side and the patch side

27-30 GHz uniformly distributed near-field probing

The 8 by 8 active phased array board showing probe switching and beamforming RF distribution, next to the antenna and probe patch face

28 GHz 8 x 8 active phased array antenna with near-field probe

Layout of the 16 by 16 dual-circularly-polarized active phased array antenna, patch face and feed face side by side

16 x 16 dual-circularly-polarized active phased array antenna for SATCOM

Exploded view of the multi-feed antenna element showing four RF ports, the stacked feed layers, via transitions and shielding vias

Reconfigurable polarization multi-feed antenna, 37-40 GHz

Fabricated FR3 4 by 4 antenna array layers, including the patch array and the coupling apertures

FR3 4 x 4 antenna array

Polar plot of measured gain against phase state, comparing outline and gain data with the auxiliary data used by the constellation modelling algorithm

Constellation modelling algorithm for rapid calibration of phased arrays

Array design and construction

The arrays are built as multi-layer printed circuit boards in which the radiating elements, the embedded near-field probes, the stripline feed network and the beamforming integrated circuits all share one stack. The figures below show how those layers are arranged, how the boards are interconnected, and how a finished array is measured.

Exploded view of the antenna element showing the cross-shaped patch, parasitic element, stripline and via transition

Element structure of the dual-polarized embedded near-field probe

Cross-section diagram of a thirteen-layer board showing the antenna element, stripline, via transitions and the flip-chip beamforming integrated circuit

Layer cross-section of the embedded near-field probe, with its flip-chip beamforming integrated circuit

Photographs of the top and bottom sides of the dual-polarized embedded near-field probe board

Dual-polarized 37 to 41 GHz embedded near-field probe, top and bottom views

Diagram of a ten-layer printed circuit board stack-up, from the parasitic patch and near-field probe on layer one to the RF and surface-mount layer

Ten-layer stack-up of the 28 GHz 64-element phased array

Diagram of four SMPM connector and adapter stacks joining a primary and a secondary printed circuit board

SMPM interconnect between the primary and secondary boards of the near-field probing array

Photograph of a 4 by 4 antenna array mounted on a motorized positioner, with a measured beam pattern overlaid

4 x 4 array on a motorized positioner during pattern measurement

Cross-section diagram of a thirteen-layer board showing the antenna element, stripline, via transitions and the flip-chip beamforming integrated circuit
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Layer cross-section of the embedded near-field probe, with its flip-chip beamforming integrated circuit
Photographs of the top and bottom sides of the dual-polarized embedded near-field probe board
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Dual-polarized 37 to 41 GHz embedded near-field probe, top and bottom views
Diagram of four SMPM connector and adapter stacks joining a primary and a secondary printed circuit board
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SMPM interconnect between the primary and secondary boards of the near-field probing array

Ongoing research projects

Large-scale active phased array antennas for SATCOM

Development of a modular large-scale phased array antenna system for SATCOM applications, enabling scalable 1024/4096-element arrays with electronic beam steering, high-gain performance, and integrated RF and thermal packaging.

Rendering of a modular large-scale active phased array antenna for SATCOM with heatsink

Modular large-scale active phased array antenna for SATCOM

Low-power-consumption lens-based phased array system

A novel lens-based phased array architecture enabling high gain, wide scan coverage and reduced power consumption.

Block diagram of the lens-based phased array showing feed selection, beam separation and array-level combining

Lens-based phased array: feed selection, beam separation and array-level combining

Fast calibration of large-scale phased arrays

A highly accurate, rapid calibration method for large-scale phased array antennas. The number of required measurements is reduced by orders of magnitude compared with conventional exhaustive calibration, while the accuracy is preserved.

Fast phased-array calibration signal chain and the resulting raw and desired constellations

Fast phased-array calibration signal chain and the resulting raw and desired constellations

Recent publications

Journal articles

  1. M. A. Chalaki, A. B. Ayed, P. Mitran, S. Boumaiza, “Assumption-Free Active Calibration of mm-Wave Phased Arrays Using Excitation Estimation via Far-Field Measurements,” IEEE Microwave and Wireless Technology Letters, vol. 36, no. 6, June 2026.
  2. J. G. Lim, A. B. Ayed, S. Boumaiza, “A Two-Tier Low-Complexity Linearization Architecture for Fully Digital mMIMO Transmitters,” IEEE Microwave and Wireless Technology Letters, vol. 36, no. 6, June 2026.
  3. Y. Chen, M. A. Chalaki, S. Boumaiza, “High-Accuracy, Fast Calibration of Large-Scale Phased Antenna Arrays via Novel Constellation Modeling Method,” IEEE Transactions on Microwave Theory and Techniques, vol. 73, no. 12, Dec. 2025.
  4. H. Barkhordar-Pour, J. G. Lim, A. B. Ayed, P. Mitran, S. Boumaiza, “Active Calibration Approach Addressing Antenna Mutual Coupling and Power Amplifier Output Mismatch in Fully Digital MIMO Transmitters,” IEEE Microwave and Wireless Technology Letters, vol. 34, no. 6, June 2024.
  5. H. Jin, A. B. Ayed, Z. He, B. Tung, S. Boumaiza, “Embedded Near-Field Probing Antenna for Enhancing the Performance of 37–41-GHz Linear and Dual-Polarized Phased Antenna Arrays,” IEEE Microwave and Wireless Technology Letters, vol. 33, no. 6, June 2023.
  6. A. B. Ayed, H. Jin, B. Tung, P. Mitran, S. Boumaiza, “Array Calibration and Digital Predistortion Training Using Embedded Near-Field Feedback Probes and Orthogonal Coding for Enhancing the Performance of Millimeter-Wave Beamforming Arrays,” IEEE Microwave and Wireless Technology Letters, vol. 33, no. 6, June 2023.
  7. A. B. Ayed, P. Mitran, S. Boumaiza, “Novel Algorithm to Synthesize the Tapering Profile for Enhanced Linearization of RF Beamforming Arrays Over a Wide Steering Range,” IEEE Transactions on Microwave Theory and Techniques, vol. 71, no. 8, Aug. 2023.
  8. A. B. Ayed, I. Jaffri, M. ElAdwy, A. M. Darwish, P. Mitran, S. Boumaiza, “Analysis and Linearization of Frequency-Multiplier-Based RF Beamforming Transmitters Over a Wide Steering Range,” IEEE Transactions on Microwave Theory and Techniques, vol. 70, no. 8, Aug. 2022.
  9. M. Almoneer, J. G. Lim, H. Yu, P. Mitran, S. Boumaiza, “Massive MIMO Precoding Methods That Minimize the Variation in Average Power and Active Impedance With Channel Conditions,” IEEE Transactions on Microwave Theory and Techniques, vol. 70, no. 8, Aug. 2022.
  10. A. B. Ayed, Y. Cao, P. Mitran, S. Boumaiza, “Digital Predistortion of Millimeter-Wave Arrays Using Near-Field Based Transmitter Observation Receivers,” IEEE Transactions on Microwave Theory and Techniques, vol. 70, no. 7, July 2022.

Conference papers

  1. A. B. Ayed, E. Gu, H. Jin, P. Mitran, S. Boumaiza, “Spatial Over-the-Air Post-Distortion Cancellation with an Embedded Distortion-Correcting Transmitter Antenna for Linearizing Phased-Array Transmitters,” 2026 IEEE MTT-S Radio Frequency Systems and Applications Symposium (IMS RFSA), June 2026.
  2. B. Tung, M. A. Chalaki, A. B. Ayed, H. Jin, S. Boumaiza, “Enhanced EIRP and Reconfigurable Polarization Multi-Feed Active Antenna Module for Millimeter-Wave Beamforming Phased Arrays,” 2025 IEEE/MTT-S International Microwave Symposium - IMS 2025, June 2025.
  3. H. Jin, A. B. Ayed, S. Boumaiza, “Dual-Band Near-Field Probing Antenna for Enhancing the Performance of Dual-Band Shared-Aperture Linear-Polarized Phased Antenna Arrays,” 2025 IEEE/MTT-S International Microwave Symposium - IMS 2025, June 2025.
  4. X. Zhang, N. Esfarayeni, A. B. Ayed, M. A. Chalaki, P. Namaki, H. Jin, S. Boumaiza, “UAV-Based Relays Using Active Phased Arrays for Non-Line-of-Sight Millimeter-Wave Communications: Real-Time Field Testing,” 2024 IEEE/MTT-S International Microwave Symposium - IMS 2024, June 2024.
  5. N. Messaoudi, A. B. Ayed, Z. He, B. Tung, P. Mitran, S. Boumaiza, “New Digital Predistortion Training Method with Cross-Polarization Channel De-Embedding for Linearizing Dual-Polarized Arrays using Far-Field Observation Receiver,” 2023 IEEE/MTT-S International Microwave Symposium - IMS 2023, June 2023.
  6. N. Messaoudi, A. B. Ayed, J. Dunsmore, S. Boumaiza, “VNA-Based Testbed for Accurate Linearizability Testing of RF Beamforming Arrays Under Modulated Signals,” 2023 100th ARFTG Microwave Measurement Conference (ARFTG), Jan. 2023.
  7. A. B. Ayed, Y. Cao, P. Mitran, S. Boumaiza, “Dual-Input Digital Predistortion of Millimeter-Wave RF Beamforming Arrays Driven by Two Non-Contiguous Intra-band Signals,” 2022 IEEE/MTT-S International Microwave Symposium - IMS 2022, June 2022.
  8. H. Yu, E. Traore, M. Almoneer, J. G. Lim, J. Xia, S. Boumaiza, “Experimental Study of the Effects of Antenna Crosstalk on the Linearity and Efficiency of 5G Sub-6 GHz Wideband 2 × 2 Transmitter Arrays,” 2021 IEEE MTT-S International Microwave Symposium (IMS), June 2021.
  9. I. Jaffri, A. B. Ayed, A. M. Darwish, S. Boumaiza, “High-Frequency Vector-Modulated Signal Generation Using Frequency-Multiplier-Based RF Beamforming Architecture,” 2020 IEEE/MTT-S International Microwave Symposium (IMS), Aug. 2020.
  10. E. Ng, A. B. Ayed, P. Mitran, S. Boumaiza, “Single-Input Single-Output Digital Predistortion of Multi-user RF Beamforming Arrays,” 2019 IEEE MTT-S International Microwave Symposium (IMS), June 2019.