Millimeter-Wave Electronics Group
Queen's University at Kingston

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Antennas Research


Advanced high-selectivity filtering antennas. A first SIW layer contains a filtering doublet and second layer above has a cavity-backed slot antenna ... read more    
Dually symmetric metal 3D printed orthomode transducer (OMT) and horn antenna with peak realized gain of 20.5 dBi at X-band ... read more
75 GHz to 110 GHz 3D printed dielectric lens and support structure on WR-10 open-ended waveguide ... read more




3D printed graded index of refraction lens and externally metallized circular horn antenna with measured peak gain above 18dBi ... read more    
Millimeter-wave long-slot traveling wave antenna with corrugated slow-wave interior structure for output beam angle control ... read more
Wide angle beam-steering reflecting surface at 30 GHz for indoor 5G environments. Structure fabricated using fused deposition modeling 3D printing technology ... read more




First known demonstration of a fluidically reconfigured lensed beam-steering antenna. Measured realized gain is 8.6 dBi and beam-steering angle is 25° at 32 GHz more    
Polarization and frequency reconfigurable patch antenna. Measured axial ratio is ≤ 3 dB for both LHCP and RHCP modes... read more
Ultrawideband magneto-electric antenna exhibiting a measured realized peak gain of 10.4 dBi at 24 GHz. Impedance bandwith is a record 75.7% ... read more




Tunable monopole antenna with measured frequency shift of up to 23.7% and impedance  band width of 29.9% ... read more    
Antipodal Vivaldi phased array exhibiting 90° of beam scanning to 6.5 GHz and realized gain of 13.1 dBi ... read more
Millimeter-wave Bull's-Eye antenna with peak gain of 18.9 dBi at 36.1 GHz and return loss below -15 dB ... read more



Sensors, Circuits and Systems

An inclinometer based on an angular microstrip half-wavelength resonator, consisting of a fixed and an overlapping, mobile part, is demonstrated. When the inclinometer is tilted, the length of the resonator and consequently, its resonance frequency changes. Experimental tests show that the inclinometer exhibits a sensitivity of 0.384 mm/° and a resolution as 0.035°. The proposed sensor is easily fabricated , cost-effective, compact, and robust.... read more


We are investigating techniques to characterize the dielectric properties of materials. Recently we demonstrated a new dual-band sensor to measure uniaxial anisotropy of dielectric materials. This sensor has two dual-mode resonators in microstrip technology. The configuration of vertical and horizontal electric field lines for the two resonance modes allows for the characterization of a uniaxial anisotropic samples placed on top of the sensor. Space mapping is used to extract the dielectric constants of the sample in two directions, parallel and normal to the surface of the sensor... read more

A six-band microstrip sensor, based on a pair of electrically coupled resonators (ECRs), for dielectric characterization of liquids is demonstrated. A pocket is milled through the substrate bottom of the sensor to contain the fluid sample, avoiding the need for a sample holder. The pocket is located in a region of high electric field intensity between the open loop resonators. Experimental tests show that the sensor can measure a wide range of εr values between 2 and 79 ... read more

The broadband complex permittivity response of widely used thermoelastic polymers used in 3D printed electromagnetic structures is reported. Fluids such as ethylene glycol and water solutions, solvents and certain oil compounds for microfluidic antenna and microwave passive circuit design are also reported. Analytic expressions for the permittivity response as a function of frequency for the materials under study were extracted and fit to the Cole-Cole equation using a nonlinear least-squares routine ... read more


Dielectric fluid channels located on a transmission line path can change in the propagation velocity of the guided wave. This effect can be used to design tunable passive microwave/milimeter-wave structures for high-power applications since fluids do not introduce signal distortion or electronic noise. The fluidic channels in the transmission line path can be modeled using a lumped-element electric circuit to facilitate circuit design... read more

Massive MIMO systems use high-resolution phase shifters for beam-forming.  We have set performance records for low phase-error, high-resolution phase shifters using  that are electronically tunable over the full 360° range. Our technique (figure right) uses coarse and fine vector scaling broadband to obtain precise  vector amplitude control, resulting in measured RMS
phase and amplitude errors of 1.25° and 0.7 dB, respectively, at 5.4 GHz. The central component of the system are microwave operational transconductance amplifiers (OTAs) pioneered in our group ... read more

Stringent linearity requirements are placed on power amplifiers (PA) found in scientific test instrumentation because the equipment's performance has to be superior to the circuits under test.  Using gallium nitride (GaN) transistors for power amplification and employing  RF digital-assist methods, our Group has developed broadband power amplifiers delivering 2 Watts of RF power over a 6 GHz band- width with a measured OIP3 above +50 dBmThe PA output stage was designed using a GaN HFET process at the Canadian Photonics Fabrication Centre in Ottawa ... read more

This distortion-cancelling circuit block (cell) reduces signal distortion in microwave amplifiers inde- pendently of the inner-workings of the amplifier. Therefore, the cell can be used to improve the performance of generic off-the-shelf amplifiers. The distortion canceller uses the principle of ... read more

Collaborators (current and former)
  • Guildline Instruments Ltd.
  • Grafoid Inc.
  • California State University Northridge, USA
  • Defense Research and Development Canada
  • INAOE, Mexico
  • Version 2 Inc.
  • Capella Aerospace
  • Test Photonics Ltd.
  • Royal Military College of Canada
  • Univ. Federal do Rio Grande do Sul, Brazil
  • Gain Microwave Corp.
  • CEIT, San Sebastian, Spain
  • Universidad de Navarra, Spain
  • Universita di Trento, Italy
  • Xi'an Jiaotong University
  • Gennum Corp.
  • Universiteit Twente, Holland
  • Politecnico di Torino, Italy
  • CINVESTAV del IPN, Mexico