Trevor S Bird

• PhD University of Melbourne
• Professor at University of Technology Sydney

About one hundred years ago, the Radio Corporation of America (RCA) set out to build a complex called Radio Central at Rocky Point, Long Island, NY that was supposed to be the “last word” in long-distance, trans-oceanic radio communication. The facility for transmission was based on a system, remarkable for the time, developed at the General Electr...

The term “antenna feeds” describe many types of antennas in common use today. Feeds are a means of supplying energy to (or receiving energy from) a secondary antenna, such as a reflector, lens, reflectarray, or beam waveguide, via a transmission line or waveguide. Everyday applications of antennas with feeds include satellite communications, radar,...

The term “antenna feeds” describe many types of antennas in common use today. Feeds are a means of supplying energy to (or receiving energy from) a secondary antenna, such as a reflector, lens, reflectarray, or beam waveguide, via a transmission line or waveguide. Everyday applications of antennas with feeds include satellite communications, radar,...

Large-element-spacing (LES) antenna arrays present an attractive proposition with their cost-effectiveness and simplified structures. However, they often encounter the challenge of high-level grating lobes. This paper proposes a novel meta-lens methodology to effectively address the grating lobe issue in fixed-beam LES arrays. The proposed approach...

The late Bob Hansen was President of the Society in 1964 and 1981, and he was made a Life Member of AdCom at the conclusion of his second term. Also, he had a distinguished career in antenna engineering. Bob’s contributions to the Antenna & Propagation Society are described in this contribution, and my collaborations with him.

The Nobel Prize-winning electrical engineer and physicist Karl Ferdinand Braun was a leading innovator and industrialist in the early history of wireless telegraphy and the inventor of numerous technologies that are now vital to electronics and television. For example, he invented the point-contact junction, the cathode-ray tube, transmitter circui...

The IEEE Antennas and Propagation Society (AP-S) in 2024 is 75 years old. This article describes the evolution of the Society from 1949 up to its 75th anniversary. The AP-S has come a long way since its beginning in 1949. From a mainly male Society to its present-day makeup, it has had four women presidents and is encouraging younger members throug...

Michael Faraday was the first to discover magnetic induction, but there were several others searching for induction effects at the same time and even earlier. This group is referred to as the “inductionists.” These included Fresnel, Ampere, and Henry, as well as Faraday. This article outlines the directions each of them took and the interactions Fa...

Heinrich Hertz’s discovery of electric waves in 1887–1888 marks a milestone in the history of science. Yet, his outcome implied a difference between the length of waves on a long straight wire and that of those in air from the same oscillator. This difference entailed either that wire waves travel slower than the speed of light or that air waves tr...

Two hundred and ten years ago, 22-year-old Michael Faraday accompanied a leading chemist of the early 1800s, Sir Humphry Davy, on a tour of France and Italy. This epiphanous trip transformed an otherwise talented and conscientious person with a deep religious faith built on the Sandemanian religious sect into a scientific genius who any school or u...

Mutual coupling between antennas and their surrounding environment has been a recognized phenomenon since the inception of antennas [1]. When an antenna element within an array operates as a transmitter, its radiated field induces electromagnetic currents in nearby elements, leading to reradiation. This coupled field can distort radiation patterns...

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Early electromagnetic (EM) horns were developed experimentally, but in the late 1930s, there was a fundamental shift in the approach. Barrow and Chu laid the mathematical foundations of EM horn antennas. An improved theory and basic practical information relating to horns were encapsulated by 1950 in Volume 12 of the Radiation Laboratory Series edi...

The IEEE Transactions on Antennas and Propagation celebrated seventy years since its inception in 2022. This history concentrates on the last forty years of publication as the first thirty years is covered in an earlier article. The issues faced by each of the past eleven Editors-in-Chief since 1982 are outlined. In the first twenty years of this p...

To paraphrase a quotation of American author James Redfield, the history of fields of endeavor such as antennas and propagation is not just the evolution of technology, but it is the evolution of thought. That is why it is important that organizations such as the IEEE and the Antennas and Propagation Society have History Committees and an IEEE Mile...

Long after Gustave Eiffel’s famous tower had been built to celebrate the first century of the Republic, many Parisians were still offended by this tour de fer and sought its removal. Eiffel argued against this, saying that the unique advantages the tower’s elevation offered for scientific research justified its permanence; the height was particul...

We briefly investigate an experiment carried out by Gian Domenico Romagnosi, in 1802, and concerning the deviation of a compass needle due to galvanic flow, indeed, cited by Ørsted himself, universally acknowledged as the discoverer of this phenomenon, in 1820, and try to understand why the former is unknown even to most of the specialists.

Arnold Sommerfeld is one of the most influential theoretical physicists of all times. His contributions to electromagnetics comprise mathematical theories of diffraction and fundamental work on wave propagation above planar ground, leading to the concept of Sommerfeld integral representations. Probably even more recognized are his contributions to...

This article looks at the careers of some pioneer women in radio and electrical sciences who were active within the hundred years of Hertz’s verification of Maxwell’s equations. Of the seven women chosen here, most were subject to major discrimination, even at universities or in the workplace, due to either being married or just being women. In man...

An expression for the reflection coefficient in a feed resulting from scattering from a neighboring reflector is derived from the reaction theorem. This expression includes the influence of an external interfering source as well. An asymptotic formula for this reflection coefficient is derived, which simplifies for an arbitrary shaped symmetrical r...

During European Microwave Week (EuMW2021), held in London in April 2022, there was a special session devoted to the achievements and impact of Prof. Peter J.B. Clarricoats, CBE, FRS, who passed in 2020. I was asked to contribute during the session. Here is my tribute in more detail.

Writing about history is always fraught with difficulty, as the writer is confronted with a range of known and unknown material. This is what occurred with me when I wrote the February 2022 column [1] in which I described how some scientific areas were made possible by developments in radar and its associated technology that, in later years, resu...

I have asked past presidents for their memories of notable events and Administrative Committee (AdCom) meetings that they attended as well as the high points of their presidential years. These could include anecdotes as well as photos they are willing to share. Many have indicated a willingness to participate.

Advances in our understanding of the world around us are often stimulated by major technological achievements. A case in point was the development of radar. It led to huge steps in remote sensing practice and the creation of two science areas, namely remote interplanetary exploration and radio astronomy.

The fundamental mode of microstrip is a quasi-transverse electromagnetic (TEM) mode with wave propagation possible down to DC. A quasi-TEM mode is the mode most commonly used in patch antennas. This chapter describes the techniques for modeling planar arrays of microstrip patches and, in particular, the effects of mutual coupling. It discusses the...

This chapter presents a more rigorous theory to support the description, and provides the techniques for analyzing mutual coupling. P.S. Carter's work had a big impact on much of the subsequent literature on antenna coupling because for the first time the coupling problem could be expressed as an equivalent circuit. The method of periodic structure...

The physical phenomenon of mutual coupling occurs through the interaction between fields and sources that are present locally. This chapter introduces a model of mutual coupling, and reviews the fundamentals of electromagnetic field equations. The electromagnetic field can be considered as the superposition of the fields associated with electric an...

Aperture antennas such as waveguides and horns are commonly used as elements for directly radiating arrays and in array feeds for reflectors. Analysis of radiation from an open-ended waveguide involves consideration of both the field radiated external to the waveguide and the field inside the waveguide. Arrays of rectangular waveguides have been st...

This chapter covers only effects related to the radiative mutual coupling between the antenna elements and in the frequency domain. It describes the measurement of mutual coupling when all elements apart from one being tested have a matched load, and radiation patterns under the same passive conditions. The basic aim of the so-called static couplin...

This chapter describes the implementation of mutual coupling in the two main applications of beam shaping and direction-of-arrival (DOA) estimation. It considers the estimation of the azimuth angle using the matrix pencil method together with uniform linear arrays with different apertures and different number of array elements. DOA algorithms fall...

This chapter describes the mutual coupling behavior of transmitting and receiving arrays qualitatively through the mutual coupling path, followed by a full-wave moment method analysis that provides insights into how the mutual coupling effect of transmitting and receiving arrays can be modeled and quantified. It discusses mutual coupling compensati...

Antenna mutual coupling occurs naturally through the electromagnetic field. It is sometimes neglected in design with serious consequences. Mutual coupling has also been used to improve the performance of arrays by placing the elements closer together or with nearby parasitics. Whilst detailed design is possible through the several accurate computer...

Wire antennas were the first type of antenna to be analyzed in any detail and for mutual coupling in particular. The moment method is widely used for solving many types of electromagnetic problems including coupling in other types of antennas. The basic symmetrical antenna is the half‐wave dipole, and the monopole driven from its base above an impe...

This chapter investigates mutual coupling in finite antenna arrays that are conformal to curved surfaces. It describes a Green's function representation of two quadric surfaces, the cylinder and sphere. The chapter provides a brief review of the literature on the application of asymptotic techniques to the analysis of mutual coupling in apertures i...

In the April issue of IEEE Antennas and Propagation Magazine , I mentioned that the History Committee is interested in receiving proposals for possible IEEE Milestones. Recently, one Milestone possibility was suggested that is quite unique from ones that have been discussed so far and also it was local to me. This is the Thompson-Lampard calculable...

The radio telescope at Parkes has been at the forefront of international research in radio astronomy since the early 1960s. It received a further accolade recently when it was honored by the award of an IEEE Milestone for its involvement in the first moon landing on 21 July 1969 (Sydney time).

T he development of horn antennas is described from their inception in the 1890s to the present. Our main objective is to describe the advancement of their fundamental features, which are often driven by applications. The horn antennas discussed here were selected based on their significant concept advancements and are listed in chronological order...

A leaky-wave antenna (LWA) on a substrate integrated waveguide (SIW) with continuous beam scanning capabilities and improved gain is presented. A 1-D longitudinal slot array SIW antenna is used as the main radiating element. It was found that due to the capacitive effect of the slot, an open-stopband (OSB) restrains broadside radiation. Although a...

A composite right/left-handed (CRLH) leaky-wave antenna (LWA) can effectively scan the radiation beam from backward to forward direction. However, in most cases a large range of frequency sweep is required to achieve a wide-angle beam scan, which could limit their applications. An in-depth study is conducted on an equivalent circuit model for a CRL...

The development of horn antennas is described from their inception in the 1890s to the present. Our main objective is to describe the advancement of their fundamental features, which are often driven by applications. The horn antennas discussed here were selected based on their significant concept advancements and are listed in chronological order...

A wideband, low-profile, tightly coupled antenna array with a simple feed network is presented. The dipole and feed networks in each unit cell are printed on both sides of a single RT/Duroid 6010 substrate with a relative dielectric constant of 10.2. The feed network, composed of meandered impedance transformer and balun sections, is designed based...

Achieving continuous backward-to-forward wide-angle beam scanning with consistent gain by employing composite right/left-handed (CRLH) leaky-wave antennas (LWAs) is reported. For structural and design simplicity, a single -layer 1-D structure is considered in which each unit cell that consists of a patch shorted centrally to the ground plane. It wa...

For many leaky-wave antennas (LWAs), it is challenging to realise beam scanning through the broadside. A problem is the presence of an open stopband (OSB), which restricts radiation in the broadside direction. In this paper, a novel substrate integrated waveguide (SIW)-based LWA is described to overcome the OSB problem and provide beam scanning con...

Mutual coupling is an important aspect of antenna design, but it is often neglected due to complexity or to obtain an approximation of the radiation pattern. Nevertheless, neglecting it is an over simplification and for best performance it should be included. In addition, some advantages follow in understanding it. Mutual coupling is a function of...

In 1989 funding was provided by CSIRO to develop capabilities in telecommunications. One of the first endeavors was to investigate "indoor communication" via wireless. An indoor wireless system that could achieve a data rate of 50Mbps or higher was envisaged at 60GHz (wavelength of 5mm). This early decision resulted in research on antennas and prop...

A ±45° dual-polarized concentrically arranged dipole antenna is proposed for base station applications. The simple, robust antenna consists of four simple dipoles arranged in a square above a flat reflector. Two specially designed feeding networks for the two polarizations are proposed to simultaneously excite the four dipoles. Without shaping the...

A method for designing circularly-polarized (CP) horn antenna is proposed, which is based on a standard pyramidal horn with a linear-to-circular polarization transformer. A compact transparent metasurface transformer is first designed to perform linear-to-circular polarization transformation, and then this is inserted in a linearly-polarized standa...

The main limitations of uniform half-width microstrip leaky-wave antennas (HW-MLWAs), namely a single operating band and only forward beam scanning, are overcome here with an HW-MLWA loaded with periodic L-shaped slots. The antenna exhibits tri-band operation and the main beam can be steered in the forward direction in one band, and in the backward...

A finite range gain expression given in the literature for open ended rectangular waveguide is improved by employing the gain correction factor approach of Polk by returning to the original aperture field integrals. In these, the phase factor is approximated to third-order and the amplitude factor to second-order with distance from the antenna from...

A technique for the design of low side-lobe pyramidal horn antennas loaded with a thin single-layer metasurface lens is extended using a subwavelength-size element. The single dielectric lens is printed on both sides with two identical subwavelength metallic square-ring resonators arrays. By placing the metasurface lens inside an existing standard...

We describe a hybrid de-embedding method that can achieve a good balance between accuracy and the number of standards required. In this new approach, the characterization of a fixture is based on a combination of electromagnetic (EM) simulation and measurement. The S-parameters of the fixture are initially obtained from EM simulations, and then mod...

A new formula for gain as a function of distance is described. It is based on the gain correction factor approach of Polk. In the new expression, gain reduction factors are obtained by field integration over equivalent aperture magnetic currents. The phase factor of the integration is approximated to second-order and the amplitude to first-order fr...

A rigorous gain measurement campaign is reported for a 4.8–11-GHz wideband double-ridged horn antenna with linear ridges. This work includes a systematic uncertainty analysis in which a detailed description is given for the uncertainty associated with various aspects of the measurement of the gain by means of the two-antenna method.

A method is reported to suppress the sidelobe radiation of a standard pyramidal horn using a thin single-layer metamaterial lens. The metamaterial lens is composed of two identical metallic dipole arrays printed on both sides of a single dielectric layer. By placing the metamaterial lens inside a standard pyramidal horn, the electromagnetic fields...

An array feeder for a reflector or a lens provides considerable flexibility in the beams that can be produced. A single beam could be obtained by combining all elements; multiple beams can be created with clusters of subarrays or the elements combined in such a way that a beam is steered by adjusting the phase and amplitude of the elements. A varie...

Reflector antennas are in widespread use in communications and radar applications in the twenty-first century. They are seen on towers for point-to-point telecommunication links, on houses for pay tv and in news items of spacecraft travelling to distant galaxies. This chapter provides an introduction to reflector antenna fundamentals for design and...

Reflector antennas are in widespread use in communications and radar applications in the 21st century. They are seen on towers for point-to-point telecommunications links, on houses for pay-tv and in news items of spacecraft travelling to distant galaxies. This Chapter provides an introduction to reflector antenna fundamentals for design and analys...

Radio astronomy has a record of providing a suitable testbed for potential future wireless devices. The reverse also occurs. This paper discusses this relationship through Australian examples and concludes that this symbionic partnership is a result of flexibility from the people involved.

A microstrip leaky-wave antenna (LWA) loaded periodically with C-shaped slots is described. Uniform half-width (HW) microstrip LWAs (HWMLWAs) operate in a single band and radiate a main beam that scans only in the forward direction. The proposed antenna operates in two frequency bands and the main beam can be steered in both the forward and backwar...

Full-wave de-embedding refers to a network de-embedding technique in which the fixture effects are removed by characterizing any connection interface using a full-wave EM simulation method instead of by measurement alone. This technique is able to achieve consistent definition of equivalent circuit voltage and current when the de-embedded results a...

A dual-polarised phase-correcting microwave transmitarray that is based on an ultrathin phase-shifting surface (PSS) has been developed at 22 GHz. The FSS element in this array has a square shape with the rotationally symmetrical geometry. It consists of two identical metallic layers etched on the two sides of a single dielectric layer. A phase-shi...

A summary is provided of developments leading to the design of the corrugated horn antenna. This is based on material sourced from the early pioneers of this technology notably Cutler, Minnett & Thomas, and Clarricoats & Olver.

Wideband microstrip leaky-wave antennas (LWAs) that radiate two symmetrical side beams are described. The two beams are steered simultaneously by sweeping the operating frequency. To achieve this, the second higher order mode of the microstrip is excited. Two electric field nulls are created between the microstrip and the ground plane using via arr...

This book is intended as an advanced text for courses in antennas, with a focus on the mature but vital background field of aperture antennas. The book is aimed at final year, MSc, PhD and Post-Doctoral students, as well as readers who are moving from academia into industry, beginning careers as wireless engineers, system designers, in R&D, or for...

A reflectarray that radiates linear or circular polarization (LP-CP) is proposed for multi-polarization applications. The reflectarray consists of two double-layer dipole arrays that are orthogonally printed on both sides of the dielectric substrate. With a linearly-polarized (LP) feeder, the antenna can transform the LP incident wave into a circul...

Arrays of dielectric rod antennas are being considered at millimeter and terahertz frequencies for a variety of applications. The mutual coupling in such an array is assessed through the measurement and computation for two dielectric rods in the array. Results are presented for linearly tapered rods and rods that give low sidelobes. It is shown tha...

A simple leaky-wave antenna (LWA) array is presented here radiates in the boresight direction. It is based on uniform half-width (HW) microstrip leaky-wave antennas (MLWAs). Uniform HW-MLWAs usually radiate a fan-shaped beam with a beam direction near boresight at lower frequenciesand near endfire at higher frequencies. One of the main challenges o...

A compact ultra-wideband (UWB) dielectric resonator antenna (DRA) with dual band-notched characteristics is proposed. A shorting conductor is attached to one side of the DRA, to reduce more than half the volume of the antenna. An inverted novel shaped strip is designed to print near the feed probe side, to achieve the dual band-notched characterist...

There are a variety of other aperture antennas which find use in specialized applications that have not yet been considered. This chapter introduces the areas of arrays and reflectors come together in the reflectarray antenna. In design and operation, reflectarrays are inherently a combination of arrays and reflectors. Since the 1980s, reflectarray...

This appendix presents the properties of Hankel transform functions. Closed-form solutions to the integral of products of Bessel functions have been described by several authors. In coupling computations involving circular apertures, products of up to three Bessel functions can occur in the mutual admittance expressions. This book covers aperture a...

Arrays of aperture antennas find wide application because of their flexibility and their ability to provide shaped patterns with low sidelobes. These find wide application because of their flexibility and their ability to provide shaped patterns with low sidelobes. This chapter discusses planar arrays and mutual coupling, including the basic radiat...

This chapter presents the theory needed for analysing aperture antennas. It examines special cases of interest pertaining to the topic of radiation from an aperture. The parameters related to radiation that are used to describe the characteristics of radiation are defined. In the near-field region, the field differs little from that in the aperture...

The microstrip patch and other printed antennas are now commonplace as they are readily combined with electronic components and integrated circuits. Another major advantage of the microstrip patch is that it can be flush-mounted planar or conformal with other surfaces, such as an aerofoil, with only a minimum of space required for the feed line. Th...

The Fock functions occur in the asymptotic representation of the circular cylinder and are also used in the description of general convex surfaces. These functions are integrals in the complex [See PDF for text that cannot be displayed in HTML]-plane of the Airy integral or its derivative. A surface Fock function of the n-th kind, order m, is defin...

This appendix explains free-space dyadic magnetic green's function. The magnetic Green's function dyadic is derived from the wave equation for a magnetic dipole in free-space. Commencing with the rotational Maxwell equations, the vector wave equation is formed for the magnetic field in the absence of electric currents. This book covers aperture ant...

Waveguide and horn antennas are based on the method of generating an electromagnetic wave from an exciter, or probe, at one end of a guiding structure with an open aperture. The wave travels to this aperture where it is mostly transmitted as radiation, and if the transition is well matched, only a small fraction of the wave is reflected back toward...

A major limitation of the planar-phased array is that as the beam is scanned from broadside, it broadens and the pattern deteriorates. The canonical structure in this chapter is a circular cylinder, but the approach is equally applicable to a cone or sphere. The chapter describes mutual coupling and radiation for a finite array of rectangular waveg...

This appendix explains complex Fresnel integrals. Several forms of Fresnel integrals have been defined by various authors, and as a result, the definition often depends on the application. The complex Fresnel integral is related to the cosine and integral functions. Another function used in diffraction theory is the modified Fresnel integral. This...

This chapter presents a summary of some useful vector identities and geometrical transformations. A vector quantity is defined in bold lettering, for example, A. A unit vector is shown as a standard variable with a caret (‘hat’) symbol. The three main co-ordinates systems used here are rectangular (x, y, z), cylindrical (ρ, ϕ, z) and spherical (r,...

In transmission, a reflector antenna concentrates energy received from another antenna, called a feed, into a narrow beam of radiation. In transmission, a reflector antenna concentrates energy received from another antenna, called a feed, into a narrow beam of radiation. In reception, the reflector re-directs the impinging field and concentrates it...

This chapter provides some background theory and introduces notation in preparation for use throughout the remainder of this text. The equations that were devised by James Clerk Maxwell and placed in differential form by Oliver Heaviside and Heinrich Hertz are introduced. Heaviside, and independently Hertz, reduced these 20 equations to the four ve...

This appendix talks about Bessel functions. Zeros of the ordinary Bessel function and its derivative can be approximated by the first two terms of McMahon's expansion. The chapter shows the recurrence relations for any of the Bessel functions which stands for any one of the ordinary Bessel functions or Hankel functions. Several applications call fo...

This appendix explains proof of stationary behavior of mutual impedance. A reason for relatively accurate results being possible with simple current approximations is that mutual impedance expression, is stationary with respect to small variations in currents on the antennas. This book covers aperture antennas, which include the main types of horns...

The already theory of aperture antennas is only part of the story in creating aperture antennas. This chapter introduces another side of antenna engineering, that of fabrication, measurement and testing. The principles of fabrication, measurement and test are summarized. These antennas are a lightweight horn for space flight, a dual reflector produ...

A simple array of half-width (HW) microstrip leaky-wave antennas (LWAs) radiates a conical beam around the boresight. Uniform microstrip LWAs usually radiate a fan-shaped beam with a beam direction near boresight at lower frequencies and near endfire at higher frequencies. Six HW-MLWAs terminated by matched loads are used in this array. The whole a...

A printed meta-surface that can reduce the electromagnetic footprint of a metallic cylinder is investigated. The meta-surface consists of a periodic width-modulated microstrip line lying on a homogeneous dielectric layer of constant thickness. When enfolded around the conformal geometry, it gives rise to an isotropic cloak wrapped around the object...