Symon K. Podilchak

• P.Eng., Ph.D.
• Professor (Assistant) at Queen's University

A low-cost leaky-wave antenna using cylindrical surface waves propagating on a grounded dielectric slab is proposed. The excited surface waves are then perturbed into a leaky-wave regime, by the addition of annular microstrip-based (“bull-eye”) gratings. Various surface-wave modes may be considered, however, we desire to achieve radiation from the...

A microstrip-based leaky-wave antenna for two-sided frequency beam scanning and broadside radiation is presented. In particular, the optimized “bull-eye” ring structure is designed to support leakage of the fundamental TM mode of the guiding structure in a regime without any other leaky- or surface-wave modes. Also by following suggested design rul...

A simple methodology is presented for the estimation and compensation of mutual coupling in antenna systems of arbitrary geometries, including antenna arrays in the vicinity of scatterers. The methodology includes both theoretical and experimental schemes, while also, does not resort to assumptions often encountered in previous mutual coupling esti...

Planar leaky-wave antenna (LWA) designs that utilize a printed surface wave (SW) source are presented. Specifically, by the addition of a periodic arrangement of width-modulated microstrip lines on top of a grounded dielectric slab (GDS), a sinusoidally modulated reactance surface (SMRS) can be realized, providing appropriate conditions for leaky w...

A fully digital antenna array is developed and experimentally tested for beamforming, null generation, and in-band full duplex (IBFD) retro-directive beam-steering. The supporting S-band array is compact and comprised of co-located transmit and receive stacked patch elements with isolation values of 40 dB. In addition, each element is fed using H-s...

A compressed sensing (CS) digital radar system based on a sparse array design is proposed for use in automotive collision-avoidance applications. The proof-of-concept radar system offers an enlarged antenna aperture, employing fewer elements and can distinguish targets at an angular separation of only 2 degrees for a bandwidth of 6.25%. This resolu...

This work proposes a low-cost, low-profile, and wideband antenna with the capability of dual-circularly polarized (DCP) radiation. The design concept utilizes a common and shared sub-array aperture for both circularly polarized (CP) states, achieving competitive performances. The basic structure comprises five patch elements and the first state, CP...

Polarimetric radars utilize dual-polarized antennas for transmitting and receiving signals with orthogonal polarizations, enabling the detection of target characteristics. This improves reliability and enhances the capability of the radar sensing system to distinguish between objects such as vehicles, stationary metallic objects, and humans, more s...

A novel metasurface radome design is presented which combines the properties of a rasorber as well as a phase gradient metasurface (PGMS). By replacing the traditional frequency selective surface or lossless layer, in a radar absorber (i.e. a rasorber) with a PGMS, a new structure can be realised which provides dual-functionality in terms of both b...

A Fabry-Perot leaky-wave antenna (LWA) with dual-differential feeding is proposed for full-duplex (FD) scenarios by offering dual-linearly polarized radiation. The compact feed system includes slots within substrate integrated waveguide (SIW) technology to excite two orthogonal fields with high isolation. The 2-D LWA aperture field is constituted b...

A circuit-based calibration system is presented for active phased arrays. In particular, to achieve the desired (and corrected) consecutive phase differences and relative magnitudes between RF channels, a computer controlled circuit system was developed for dynamic adjustment. The proof-of-concept demonstrator uses a phase sensor, phase shifters (P...

Planar metasurface lens structures based on microstrip technology, optimized to control the propagation of surface waves (SWs), are presented. Two different lenses are studied, i.e., a converging or plane-wave-like lens and a diverging lens. Near-field simulations and measurements are reported to demonstrate the guiding features of the designed len...

This letter presents a three‐dimensional (3‐D) printed metallic antenna array that combines folded‐shorted patches (FSPs) and meandering for structure compactness. The design provides dual‐band functionality, operating in the L‐band and the S‐band. The compact and broadband feeding network, which is also integrated onto the backside of the antenna...

A compact antipodal Vivaldi antenna array (AVAA) with ultra-wideband (UWB) beam steering capabilities is presented. The fabricated and measured array prototype has good matching from about 1.5 GHz to 11 GHz (147%) for all ports and can achieve wide angle steering, with low side-lobe and cross-pol levels, within that range. The compact 118.6mm x 81m...

This paper presents a novel radio frequency fingerprint (RFF) enhancement strategy by exploiting the physical unclonable function (PUF) to tune the RF hardware impairments in a unique and secure manner, which is exemplified by taking power amplifiers (PAs) in RF chains as an example. This is achieved by intentionally and slightly tuning the PA non-...

A self‐calibrating circuit system for use within active phased array antennas is presented. The system addresses the issue of unwanted channel phase imbalances and random phase errors which can deteriorate array performance. Basically, unwanted insertion phase offsets that can originate within each RF channel, due to the supporting and active circu...

The development of a dual‐band folded shorted patch (FSP) antenna array is presented which offers dual‐circularly polarized radiation. Applications include small satellites like CubeSats and picosatellites. The proposed 2 × 2 FSP array design operates at 1.1 and 2.4 GHz and offers good radiation performance in terms of minimal reflection coefficien...

The modelling and design of a full wireless microwave communication system is examined, where the signal propagates within an overmoded circular metallic pipeline. Applications include the oil and gas industry. A specific link budget equation was also developed for the S-band transmission system and measured successfully using a 36-meter carbon ste...

Flexible and lightweight textile-based coaxial transmission lines for wearable applications are presented. In particular, textile yarns defined by copper (Cu), polyester (PES), and polytetrafluoroehtylene (PTFE) materials were used to design transmission line prototypes offering a 50- $\Omega$ characteristic impedance. These structures, which have...

A new half-annular bull-eye leaky-wave antenna (LWA) design with suppressed open stopband (OSB) and integrated feeding is presented. The 2-D aperture offers a pencil beam with scanning through broadside and with stable gain values as a function of frequency. To achieve directional radiation, a TM $_{0}$ surface wave supported by a grounded dielect...

A circularly polarized (CP) S-band patch antenna that makes use of a multi-port setup to improve its radiation efficiency and compactness is presented. The design highlights a single-element patch with eight-port feeding, by using compact slot meandering. To the best knowledge of the authors, no earlier literature discloses a similar single-element...

A high isolation antenna is presented which offers dual-polarization monopulse beam patterns, making the design suitable for polarization diverse or full-duplex (FD) systems. The single-layer structure is defined by a network of 2-D sub-arrays oriented in a cross-shape configuration using series-fed slots in substrate integrated waveguide (SIW) tec...

Radio frequency fingerprint (RFF) identification distinguishes wireless transmitters by exploiting their hardware imperfection that is inherent in typical radio frequency (RF) front ends. This can reduce the risks for the identities of legitimate devices being copied, or forged, which can also occur in conventional software-based identification sys...

A miniaturized planar Yagi-Uda antenna for integration with PicoSats or other SmallSat missions is proposed. Miniaturization techniques, such as meandering and 1-D artificial dielectric concepts to reduce the guided wavelength, are employed to overcome space constraints imposed by the SmallSat footprint while still maintaining good performance for...

A Jaumann-like rasorber is examined which offers wideband absorption, angular stability, and polarisation insensitivity. The structure is defined by three layers with two resistive layers placed on top of a lossless layer. Also, all three layers use capacitors to ensure compactness for the metasurface rasorber. These features provide broad angular...

The short wavelength of the mmWave frequency band suggests that even narrow-width blockers affect the mmWave signal strength. There is a lack of literature investigating the effect of small-sized blockages. In this study, we present new measurement results for five metallic objects, mimicking objects indoors or in the street, where the obtained res...

Automotive radars are designed to enhance road user safety and reduce the number of accidents on public roads and there is a constant demand to improve the performance for these radars. In this paper, a novel proof-of-concept multiple-input multiple-output (MIMO) radar architecture is presented by frequency modulated continuous waveform (FMCW) tran...

The feasibility of a wireless system is examined for propagation inside an oil and gas well pipeline. The well bore environment is modeled as a circular aluminium pipe and treated as a metallic microwave waveguide. The experimentation test bed was based on the nominal diameters of commercially available oil and gas well pipelines. At the transceive...

This letter presents a substrate-integrated waveguide (SIW) antenna for CubeSat applications. The compact structure utilizes middle-point feeding and shorting walls to achieve broadside radiation in the far-field at two distinct frequencies. In particular, this dual-frequency behavior is related to the transition from a dominant leaky wave (LW) on...

A planar quasi-endfire surface-wave antenna (SWA) using substrate integrated waveguide (SIW) technology for integration with CubeSats and other small satellites is proposed in this letter. This antenna can be attached to the body of the satellite, resulting in a compact and low-cost design. A quasi-endfire beam pattern is achieved by the radiation...

A new two-port dual-polarized planar antenna with an integrated feeding circuit for in-band full-duplex (FD) (IBFD) applications is presented. The antenna consists of four H-shape slots, stacked patches for enhanced bandwidth (BW), and a separate layer of two differential (0° and 180° split) power dividers connected using vertical transmission line...

We present the design of a novel K-band radar architecture for short-range target detection. Applications include direction finding systems and automotive radar. The developed system is compact and low cost and employs substrate-integrated-waveguide (SIW) antenna arrays and a 4×4 Butler matrix (BM) beamformer. In particular, the proposed radar tran...

A compact crown-shaped planar antenna integrated with a 3 × 3 artificial magnetic conductor (AMC) ground is presented for wearable internet of things communications. Simulations were performed using the commercial software FEKO based on two approaches: characteristic mode analysis and the method of moments. This paper aims to optimize the operation...

This paper describes an innovative remote surface sterilization approach applicable to the new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The process is based on the application of a liquid film on the surface or object under sterilization (OUS). A beacon signal is required to self-steer the transmitted power from th...

A new four-port dual-polarized antenna and array are presented for In-Band Full-Duplex (IBFD) applications, offering high inter-port isolation. The single-element antenna system consists of four H-shape slots, stacked patches for wide bandwidth, and two external hybrid couplers. The multilayer antenna is well matched from about 2.1 to 2.4 GHz and p...

A compact two-port feeding circuit that supports a dielectric resonator (DR) element is presented for applications requiring polarization diversity. The L-band structure consists of a cylindrical DR that can generate right-handed circular polarization (RHCP), left-handed circular polarization (LHCP), and linearly polarized radiation. The DR dimensi...

This article presents a novel dielectric resonator antenna (DRA) with an eight-port feeding system offering gain and polarization diversity. The single-antenna unit is defined by a square arrangement of four aperture coupled slots (ACSs), hybridized with the radiation of the dielectric resonator. Basically, an atypical feeding layout, realized by t...

Two planar Yagi-Uda antenna designs for integration on the solar modules of PicoSats are proposed. One antenna is designed to be implemented on top of the solar cell while the other configuration is based on the removal of one of the extra solar modules to ease design whilst using FR4 as a substrate underneath. Miniaturization techniques such as ef...

A pattern-reconfigurable microstrip patch array antenna with switchable beams for WLAN application is presented. The proposed 1×2 array can steer the beam approximately to-30 0 , 0 0 , and +30 0 in the H(xz)-plane with the aid of DC biasing circuitry. An external switching circuit was also developed to measure the prototype effectively. The overall...

The millimetre-wave (mmWave) band communication system suffers from its susceptibility to blockage. Unlike human blockage, which has been extensively investigated in the literature, the impact of other small objects on signal strength, such as metal road signs, is not completely understood. In this study, we measure and investigate the attenuation...

A decagonal-shaped split ring resonator metamaterial based on a wearable or textile-based material is presented in this work. Analysis and comparison of various structure sizes are compared considering a compact 6×6 mm 2 metamaterial unit cell, in particular, where robust transmission-reflection (RTR) and Nicolson-Ross-Weir (NRW) methods have been...

A multi-fed radially periodic two-dimensional leaky-wave antenna is proposed for the generation of a directional beam continuously scanning in elevation by changing the frequency, and over a discrete number of directions in azimuth when activating different elements of the feeding system. The structure is planar and constituted by a circular ground...

We propose the design and test of a 2-D Fabry-Perot structure based on a multilayer slab arrangement fed by a circular array of simple sources. Such a class of planar leaky-wave antenna can be made by low-loss commercial laminates and it is bounded on top by a sub-wavelength partially-reflecting surface. The antenna is designed to suppress undesire...

A wearable textile antenna with dual-band and dual-sense characteristics is presented in this work. It operates at the 2.45 GHz band for WBAN and WLAN applications, and at the 1.575 GHz band for Global Positioning System (GPS) applications. An antenna backing based on an artificial magnetic conductor (AMC) plane operating at 2.45 GHz band is introd...

A flexible folded-shorted patch (FSP) antenna with dual-band functionality for wearable applications is presented. The proposed antenna is operational at 400 MHz and 2.4 GHz and can be considered compact for the lower operational frequency band (0.13λo × 0.13λo × 0.02λo). Flexible polydimethylsiloxane (PDMS) is used as the substrate due to its rela...

This article describes a full-bridge rectifier and a receiving antenna array for operation within an innovative wireless power transmission (WPT) system. A high-power transmitter using circularly polarized free-space waves and based on a retrodirective antenna array technology is also employed to boost the overall received RF power at the input of...

A two-dimensional leaky-wave antenna fed by an array of fully integrated sources and able to provide fixed-frequency continuous beam steering through broadside is presented in this contribution. The structure is constituted by a “bull-eye” leaky-wave antenna fed by a proper arrangement of four surface-wave launchers, whose excitation coefficients a...

The design and operation of a compact antenna array offering circularly polarized (CP) radiation for picosat and other small satellites for communication applications is presented. The proposed array combines folded-shorted patches (FSPs) and meandering for antenna miniaturization. Realization of CP is achieved by a compact and planar feed circuit...

An isolation technique, which does not require conventional circulators, is proposed for the realization of a simple and low-cost aperture-coupled circularly polarized antenna for application to full-duplex devices. The approach is based on the use of slotlines loops to provide surface current cancellation in specific regions of the antenna structu...

A retrodirective antenna (RDA) array for wireless power transmission (WPT) is presented. Applications include the wireless charging of mobile phones and other handheld devices. The reported RDA defines an active high-power transmitter module which retrodirects a received beacon tone back to a mobile unit by circularly polarized (CP) free-space radi...