M.J. Ammann

Technological University Dublin - City Campus | TU Dublin · School of Electrical Engineering Systems

A compact series-fed, omnidirectional printed dipole array for mm-wave bands n257, n259, and n261 is proposed. A series feed technique with microstrip to grounded-coplanar-waveguide transition was used to feed the antenna. The prototype was fabricated and measured for the range from 27.25 GHz to 28.5 GHz. The measured peak gain is 10.3 dBi with a m...

The paper proposes methodology to employ circularly polarized UWB signals for simultaneous measurement of orientation and distance changes between transmitter and receiver. The proposed technique uses the rotational Doppler effect on circularly-polarized pulsed communication. The amplitude of a circularly-polarized signal is immune to polarization...

A calibration method for a high-resolution hybrid MIMO turntable radar imaging system is presented. A line of small metal spheres is employed as a test pattern in the calibration process to measure the position shift caused by undesired antenna effects. The unwanted effects in the antenna near-field responses are analysed, modelled and significantl...

A printed edge-fed counterpart of the wire Bruce array antenna, for frequency scanning applications, is presented in this paper. The unit-cell of the proposed antenna consists of bowtie and semi-circular elements to achieve wide bandwidth from below 22 GHz to above 38 GHz with open-stopband suppression. The open-stopband suppression enables a wide...

A printed edge-fed counterpart of wire Bruce array antenna, with open-stopband mitigation at broadside, is presented. The proposed antenna comprises of 11 meandered unit-cells periodically modulated in congruence with wire Bruce array antenna's theory. To mitigate the effects of open-stopband, the horizontal and vertical lengths of unit-cell are ad...

Refined optimisation of complex curve-linear shaped radiators, such as travelling wave Vivaldi antennas, can be achieved by considering simulated near-fields to interpret in detail the structural influences of a design. The relationships between space- and time- distributions of electromagnetic (EM) energy clusters and the geometric features are re...

The aim of this work was to develop multimodal anthropomorphic breast phantoms suitable for evaluating the imaging performance of a recently-introduced Microwave Imaging (MWI) technique in comparison to the established diagnostic imaging modalities of Magnetic Resonance Imaging (MRI), Ultrasound (US), mammography and Computed Tomography (CT). MWI i...

A tri-band mm-wave planar Bruce array antenna for fifth generation communications (5G) is presented. The 16-element planar Bruce array antenna is simulated and fabricated on Rogers RT/Duroid 5880 substrate with thickness of 0.254 mm. For a compact and simple structure, the antenna has a highly directional fan-beam radiation pattern at broadside and...

A calibration method for a high-resolution hybrid MIMO turntable radar imaging system is presented. A line of small metal balls is used in the calibration process to measure the position shift caused by undesired effects of the antennas. The unwanted effects in the near-field antenna response are analysed and significantly mitigated based on the re...

The millimetre wave (mm-wave) frequency band is widely used for imaging in security systems, medical applications, through-wall imaging and non-destructive testing due to its low propagation loss and adequate resolution. Based on the Friis transmission equation, the Ka-band is commonly used to exploit a lower propagation loss compared to the remain...

A planar Vivaldi antenna structure with a core element is proposed for high gain. Techniques to achieve a significant gain improvement over the full Ka (24–40 GHz) band are implemented; including a frequency-independent excitation method, the introduction of logarithmic ripple on the lateral edges and enclosing the antenna in a dielectric material.

The efficiency and beam-scanning performance of a compact beam reconfigurable antenna are presented. The proposed design achieves flexible switchless bidirectional radiation pattern of 360° in azimuth by using phase variations between its 3 ports. Antenna miniaturization is performed by dielectric loading; designs are presented for 4 different perm...

The paper investigates the use of CubeSat body as an UHF antenna for 435 MHz band. Since the lowest characteristic modes in 1U CubeSat become significant around 1 GHz, a set of four arms is developed to decrease this frequency and realize compact antenna that can be enclosed within in a sphere of 0.3 wavelength diameter. The antenna does not rely o...

This paper investigates design considerations and challenges of integrating on-chip antennas in nanoscale CMOS technology at millimeter-wave (mm-wave) to achieve a compact front-end receiver for 5G communication systems. Solutions to overcome these challenges are offered and realized in digital 28-nm CMOS. A monolithic on-chip antenna is designed a...

Full-duplex radios have become a topic of increased interest in the wireless communications community. As part of this development, many efforts were directed to passively decrease the self-interference level at the antenna outputs. However, in many proposed solutions transmission and reception occur through different propagation channels. This art...

A millimeter wave Grid Array Antenna for fifth generation (5G) communications is presented. The 20 cell, nearly-rhombic, 40×40 mm2 Grid Array Antenna structure is simulated and fabricated on a Rogers RT/Duroid 5880 substrate with thickness of 0.25 mm. The grid array has |S11|<-10dB for two frequency ranges in the upper 26 GHz millimeter wave band a...

A method and apparatus for measuring rotation of a target are disclosed. In one embodiment circularly or elliptically polarised radar signal is directed to a dipole target lying in the plane of the wavefront, which scatters and returns a linearly polarised signal to a circularly polarizing receive antenna. Changes in phase of the receive signal are...

The paper proposes an electrically small pattern reconfigurable antenna, which allows flexible beamforming with the antenna diameter being λ/5. The antenna has 3 ports, each designed to radiate a different spherical mode. By applying appropriate phase shift the antenna allows to flexibly sweep its bi-directional radiation pattern across a 360° azim...

A dual-stub co-planar Vivaldi antenna with a parasitic element is presented. The dual stub is coupled between the parasitic element and two tapered slots. The parasitic element shape and size is optimised. The use of slits on the outer edge of the ground plane is shown to provide control of beamwidth and maximum gain. A bandpass filter is used for...

A millimetre wave rectangular microstrip patch antenna array for fifth generation communications (5G) applications is presented. With the increase in demand for high data rates and capacity, there is a need to include mm-Wave frequencies for 5G. The 4×2 patch array is simulated and fabricated on a Rogers RT/Duroid 5880 substrate with a thickness of...

This paper proposes a simple, low-cost multi-mode patch antenna combining good MIMO performance with precise Angle of Arrival (AoA) estimation. The AoA is based on the monopulse antenna concept, however, unlike in radar applications, the necessity for complex circuitry is replaced by the intrinsic properties of even and odd resonant patch modes. Th...

A 5G millimeter-wave radio over fibre optical fronthaul system based on optical heterodyning, utilising an externally injected gain switched distributed feedback laser, is successfully demonstrated. Five bands of UF-OFDM are transmitted over 25 km of fibre and a 28 GHz Vivaldi Antenna wireless link. Transmission performance below the 7% FEC limit i...

A new directional modulation system which uses radiation pattern data for modulation encoding is proposed. The approach allows compact multiport antennas (e.g. MIMO capable antennas) to be used for directional modulation, replacing extensive arrays. The modulation weighting coefficients are calculated with a fixed, antenna specific equation, thus r...

This paper proposes an improved technique to calculate the Envelope Correlation Coefficient (ECC) by directly using the spherical mode spectrum of the antenna under test. The technique avoids errors due to numerical pattern integration and simplifies post-processing for near-field measurements. The technique is successfully tested on two different...

This paper proposes a new approach to reduce weight and complexity of VHF/UHF cubesat antennas by utilizing a dual band antenna, rather than standard two-antenna system routinely implemented in cubesats. Three systems are compared: A standard system with separate transmit/receive dipoles, a dual-band dipole for both transmit and receive and a dual-...

A new equivalent circuit based Wheeler Cap method to calculate MIMO efficiency is introduced. The method works without the necessity for interpolation by avoiding concur of resonating and cavity modes. The method is tested with a set of three differently correlated MIMO antennas. Results are compared with the recently proposed quality factor method...

The usage of driving assistance systems that are based on V2X communication technologies as ITS-G5 are a promising technology to increase road safety as well as traffic efficiency. To allow for communication even in challenging propagation scenarios (such as busy urban intersection), we investigated a new concept for rooftop mounted beam-steerable...

A high gain Vivaldi antenna employing an integrated core element is proposed. The maximum antenna gain is 16.9 dBi and it performs better than 14 dBi over the complete Ka (24 - 40 GHz) band. The design methodology, excitation arrangement and field distribution features are described.

This paper presents the first-ever millimeter wave on-chip antenna (AoC) in 28 nm CMOS technology. The addition of artificial magnetic conductor (AMC) can increase the antenna's power gain and radiation efficiency to −1.75 dBi and 22%, respectively, with an occupied area of 0.95 mm×4.75 mm at 38 GHz. This structure is intended for fully integrated...

A dual band PIFA antenna for portable devices is presented. It operates in the 450 LTE (449 − 461 MHz) and GSM 900 (876 – 922 MHz) frequency bands. The proposed antenna which has a very compact size of 7 (0.01λ0) × 7 × 70 (0.1λ0) mm3 and is suitable to integrate in small envelopes, consists of two branches and a metallic patch. The low cost and ea...

A new design approach of a dual-stub coplanar Vivaldi antenna with integrated filter is presented. The dual-stub excites coupling between a parasitic elliptical element and tapered slots. The dimensions of the parasitic element are studied and optimized for wide beamwidth. The bandpass filter is used for sub-harmonic suppression and pattern shaping...

A new design approach of a dual-stub coplanar Vivaldi antenna with integrated filter is presented. The dual-stub excites coupling between a parasitic elliptical element and tapered slots. The dimensions of the parasitic element are studied and optimized for wide beamwidth. The bandpass filter is used for sub-harmonic suppression and pattern shaping...

A back-to-back microstrip patch antenna with a switchable pattern is proposed for WLAN applications. The patch elements, printed on FR-4 substrates with a common ground plane, are switched with a single-pole double-throw PIN diode circuit. Switching the feed selects either of two identical radiation patterns in the opposing hemispheres for spatial...

A new adaptive technique for steering the direction of minimum axial ratio (AR) (<1 dB) toward the reflected or jamming signal is proposed for global navigation satellite systems antennas. It relies on simple, low cost commercially available circularly polarized antenna elements without influencing their gain. Its performance is demonstrated using...

The paper proposes a method for simultaneous measurement of rotation and distance by using a multi-band circularly polarized radio links. The method is realized using a standard dual-band patch antenna, operating at 1.58 GHz and 2.27 GHz, with respective axial ratios of 1.7 dB and 1.0 dB. Both link distance and antenna rotation were varied from a r...

Dye-sensitised solar cells are proposed as a solarantenna in the form of a proof-of-concept dipole operating at 1.1 GHz. Comprised of glass plates in basic rectangular shapes, various material properties are considered for impact on antenna performance at three phases of assembly. Simulated and empirical analyses indicate how such low-cost solar ce...

The focus of UWB antenna research activity has matured in recent years and currently mainly concentrates on applications such as biomedicine and security. Early UWB antenna designs were driven by the FCC allocation of spectrum in 2002 and focussed on obtaining wide impedance bandwidths with reasonable group delay characteristics. Many of these were...

A low-cost solution for antennas integrated into solar cells, allowing their implementation in solar tracking installations is proposed. The proposed passive device autonomously adjusts the phase shift of a two-element array proportional to the panel rotation. Consequently, the main beam is steered to compensate for panel rotation and maintain a ra...

This paper introduces a feasibility study of a scanning system for applications in biomedical bone imaging operating in the microwave range 0.5 – 4 GHz. Mechanical uncertainties and data acquisition time are minimized by using a fully automated scanner that controls two antipodal Vivaldi antennas. Accurate antenna positioning and synchronization wi...

The paper investigates a new approach to analysis and design of inhomogeneous linear antenna arrays. The approach relies on omnidirectional antennas, which exhibit linear phase variation of the radiation pattern in the far-field. By appropriately combining different phase variations with a spacing between antennas, one can obtain a performance not...

The paper investigates a new application of a previously designed pattern reconfigurable antenna. A single antenna is able to rotate its dipole-like radiation pattern on a single axis. This paper demonstrates how once can efficiently extend this performance by combining two such antennas into a linear array. The proposed array allows continuous ste...

Envelope correlation coefficient is a key parameter for MIMO antennas, allowing assessment of the signal correlation between multiple input/outputs of an antenna system. A simplified method allows calculation of this coefficient by using only S-parameters, however the method is less accurate and only applies to lossless antennas. This paper discus...

The paper proposes the use of a switchless reconfigurable antenna for a compact and low-cost directional modulation system. These systems are known to provide enhanced privacy of wireless systems, however the necessity for large antenna arrays prevents their implementation in small wireless sensors. The proposed work aims to bridge this application...

A simple pattern reconfigurable printed inverted-F antenna is presented for WLAN applications. The proposed low profile monopole antenna consists of one main radiator and one parasitic element. The antenna is capable of switching both the pattern and polarization across the full 205 MHz bandwidth, using only one PIN diode. The measured gain for the...

The paper proposes a new method for private point-to-point communication. It employs a monopulse antenna system, where the summary beam is used to transmit the useful signal to the intended receiver, while the differential beam is used to generate noise, in order to bury the signal for angles other than boresight. The method is tested using simulat...

An ultra-wideband solar Vivaldi antenna is proposed. Cut from amorphous silicon cells, it maintains a peak power at 4.25 V which overcomes a need for lossy power management components. The wireless communications device can yield solar energy or function as a rectenna for dual-source energy harvesting. The solar Vivaldi performs with 0.5 - 2.8 dBi...

A novel reconfigurable antenna capable of rotating a bi-directional pattern by 360° in azimuth is proposed. The antenna has two ports, no aperture switching components and offers a more compact solution than an array. It provides a reconfigurable pattern in the band 2.525 to 2.595 GHz and a fixed omnidirectional pattern from 2.235 to 2.725 GHz. The...

The use of contactless payment methods for consumer transactions is becoming increasingly popular - 1.1 billion contactless transactions were made by Visa cardholders across Europe in the 12 months to July 2015 (€12.6 billion total value). Typically the contactless payment process uses a Radio Frequency (RF) enabled smartcard or a Near Field Commun...

In this issue’s “Wireless Corner” column, the authors present a compact, low-cost antenna to be used in smart metering or smart grid devices in the lower ultrahighfrequency band. This low-frequency band has the advantage of providing larger coverage areas, but designing a compact antenna is challenging. The proposed antenna is a meander-line-folded...

A back-to-back linearly polarized patch antenna with a single microstrip line feed is proposed for WLAN applications. The antenna consists of two identical rectangular patch elements on the front and rear sides of a common ground plane. One patch antenna can be switched on at a time using a single-pole double-throw PIN diode switching circuit, offe...

A dual band antenna for machine-to-machine applications in ISM and GSM bands is presented. The antenna is compact and operates at 409-442 MHz and 800-1224 MHz, with good efficiency and gain across the frequency bands. A parametric investigation of key geometrical parameters is reported.

A simple polarization reconfigurable printed monopole antenna is proposed for wireless applications. Conducting strips are used to connect to the ground plane providing the necessary additional modes for circular polarization. Linear polarization, right-hand or left-hand circular polarization can be realized using only two PIN diodes, which connect...

A compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of splin...

Introduction: The use of a wireless footwear telemetry antenna (FTA) system, developed by the Antenna & High Frequency Research Centre at DIT, could negate the use of wires in plantar pressure measurement devices and allow unencumbered gait monitoring in patient groups. Methods: Ethical approval for this study was granted by the RCSI Research Ethi...

A wearable microwave hyperthermia system for treatment of breast cancer is proposed to overcome the limitations of currently available clinical applicators. The applicator incorporates an array of rectangular patch elements and a shared hemispheric conformal groundplane. The energy deposition capabilities of the proposed system are evaluated with p...

Introduction: The use of a wireless footwear telemetry antenna (FTA) system, developed by the Antenna & High Frequency Research Centre at DIT, could negate the use of wires in plantar pressure measurement devices, allowing unencumbered gait and running analysis (1). Methods: Ethical approval for this study was granted by the RCSI Research Ethics Co...

The first dual-band printed monopole antenna for Wireless M-Bus and M2M applications with operation in the VHF and lower UHF band is presented. The antenna operates at 169 MHz and 433 MHz. The miniaturisation of the proposed compact antenna is based on a double-sided meandering structure offering an easily controlled large frequency-ratio. The ante...

This paper introduces the prototype of a scanning system operating in the microwave range 0.5–4 GHz with strong potential for biomedical applications such as breast cancer detection or to assess shape-discontinuity in bones. A fully automated scanner was designed to reduce mechanical uncertainties and data acquisition time. Accurate positioning and...

A dual Planar Inverted-F-Antenna for M2M application is proposed. The antenna covers the lower long term evolution (LTE) band (690–960 MHz) and partially, the upper LTE band (1670–2067 MHz). The antenna is low cost with omnidirectional radiation characteristics. The measured total efficiency and gain are better than 58% and 0.8 dBi across the opera...

In this work,a compact printed spiral monopole antenna operating in the FM frequency band (88{108 MHz) is reported. The antenna is printed on a 100mm £ 50mm PCB layer providing more than 20MHz bandwidth at ¡2 dB threshold and is easily fabricated with low manufacturing cost. The antenna was also measured and simulated on 900mm £ 900mm ground plane...

The paper discusses recent developments and challenges in the design of small omnidirectional circularly-polarized (CP) antennas. Although omnidirectional CP coverage is easily achievable using antenna arrays, it is just recently that small and low-cost antennas delivered this functionality. The paper addresses practical design problems for these a...

The paper investigates an array of two reconfigurable circularly-polarized antennas with omnidirectional radiation pattern. The results are based on a previously reported antenna, which offers a steerable dipolelike radiation pattern. Its capabilities allow reception of a signal from practically any direction with steering realized by rotation of t...

The paper proposes a dual-port patch antenna for MIMO applications, optimized using surrogate-based optimization techniques. The antenna uses two resonant modes (TM100 and TM200) to generate two independent radiation patterns. To enhance the bandwidth of TM200 mode, the patch ground plane was realized as a meshed surface. The proposed approach prov...

An innovative method to measure the angular velocity using circularly polarized antennas is proposed. Due to the properties of circular polarization, the angular velocity is frequency modulated (FM) on a wireless carrier. This enables a low-cost precise continuous measurement of angular velocity using a standard FM demodulator. The hardware can be...

A 433 MHz antenna is proposed for integration with the insole of footwear for a body area network. The folded dipole design with an asymmetric groundplane radiates from its edges and considers the close proximity of the human foot and ground surfaces. It functions for different ground conductivity conditions and an on-body communication link with a...

A circularly polarised solar cell antenna consisting of four sequentially rotated printed inverted-F antennas is proposed. Four multicrystalline silicon solar cells act as the ground plane and the antenna is suitable for low-power airborne communication nodes and wireless sensor networks. The antenna design was developed to allow 100% insolation of...

Issues associated with exploiting a multicrystalline silicon solar cell as a ground plane for an Inverted-F Antenna at 2.45 GHz are reported. Current flow on the solar lattice greatly affects the impedance match of a microstrip transmission line positioned above the solar cell. As a result, an antenna designed with a transmission line parallel to t...

The paper demonstrates how a modulation constellation can be used to steer the radiation pattern of a reconfigurable omnidirectional circularly polarized antenna. The proposed approach offers the benefit of digital beamforming while using a single antenna: the steering can be executed by low frequency electronics and independently for each frequenc...

The integration of a low-profile antenna array with a multicrystalline silicon solar cell capable of powering a low power wireless sensor at 2.45 GHz is reported. Lattice bus bars on the cell are exploited to minimize antenna shadows from low profile antennas and transmission lines for a higher output power. The dual inverted-F array improves gain...

The focus of UWB antenna research activity has matured in recent years and currently mainly concentrates on applications such as biomedicine and security. Early UWB antenna designs were driven by the FCC allocation of spectrum in 2002 and focussed on obtaining wide impedance bandwidths with reasonable group delay characteristics. Many of these were...