TUTORIAL on Treatment of Some Fundamental Topics in Antenna Theory

Date: Dec 12, 2022, 8.30-17.30 Hall: Bidar

Time (Hrs) Topics Description
08.30 - 9.30 Brief introduction to notation and some preliminary concepts including charge as a fundamental source of EM fields: Prof. Prabhakar Pathak, OSU, USA
  1. Current flow viewed as net motion of charges. Development of complete expressions for the exact EM fields of general current distributions.
  2. Various approximations for the corresponding fields of antennas in their reactive, Fresnel and Fraunhofer regions, respectively.
  3. Complex EM power conservation theorem and its use in developing a general expression for antenna impedance. Use of the antenna impedance in describing an equivalent circuit for a transmitting antenna.
9.30 -10.30 Development of EM Reciprocity and Reaction Theorems for Antennas in the frequency domain: Prof. Prabhakar Pathak, OSU, USA
  1. Field/Lorentz form of reciprocity theorem.
  2. Development of circuit form of the reciprocity theorem for a pair of coupled antennas. Concept of mutual impedance/admittance. A two port network for representing a pair formed by a transmitting and a receiving antenna system.
  3. Generalized reciprocity/reaction theorem in mixed circuit-field form leading to specific field based expressions for calculating the mutual impedance/admittance between a pair of antennas. Examples involving coupled dipoles, as well as coupled slots in a ground plane are discussed.
10.30 -11.00 Tea Break
11.00-12.00 Additional applications of generalized reciprocity/reaction theorems: Prof. Prabhakar Pathak, OSU, USA
  1. Reaction (generalized reciprocity) theorem for calculating the voltage induced in a receiving antenna from a distant/far zone transmitting antenna.
  2. Thevenin/Norton circuit for a receiving antenna.
  3. Reaction theorem for calculating the far zone radiation pattern of a patch antenna without the use of a complicated Sommerfeld integral form of the microstrip Green’s function.
12.00-13.00 Slotted rectangular waveguide array analysis: Prof. Prabhakar Pathak, OSU, USA
  1. Resonant (narrow band ) broad-wall slotted waveguide array theory for generating a broadside beam.
  2. Non resonant broad-wall slotted waveguide array as a leaky wave antenna for frequency scanned beam applications. Forward and backward beams.
13.00 -14.00 Lunch Break
14.00-15.00 UWB Future 5G Transceivers & Wearable Electronics: Prof. John L. Volakis, FIU, Miami, USA

Future communication links (future 5G) will require higher data rates, multiple beams, and higher transmit/receive gains, in addition to smaller weight, cost, and power. With the growing interest for reduced size platforms and the requirement for ultra-wideband (UWB) performance to address multi- functionality, there is a strong need for UWB RF front-ends with ultra flexible interfaces. The latter will include millimeter wave and THz capabilities to enable increased spectral efficiency, multi-functionality and security. Simultaneous transmit and receive (STAR) transceivers are also becoming a focus for the coming decade. Further, in recent years, a variety of flexible fabric-based electronics have been proposed. To this end, our team proposed a new class of conductive textiles that have demonstrated unique capabilities in terms of flexibility, durability and manufacturing-ease using standard automated embroidery machinery. These electronic threads (E-threads) have the capability to generate fully embroidered microwave circuitry that has the same electrical properties as traditional microwave circuits printed on PCBs. As such, a new class of wearable devices that are fully integrated and inconspicuously placed within clothing is possible. This presentation will focus on innovative methods for handling UWB communications with RF front end and back-end capabilities having historically low power and game-changing frequency-independent operation. They will include low power MIMO and beamforming across large bandwidths, from MHz to millimeter wave bands. Challenges in realizing future textile-based electronic devices, including wearable wideband transceivers will be presented. Among them, reliable wearable interconnects, chipsets that are less bulky and integrated with the textile circuitry, and manufacturing challenges will be discussed.

15.00-16.00 Constructive Parameters of Metamaterial: Lorentz Versus Floquet Models : Arun K. Bhattacharyya, Fellow IEEE, Center of Excellence, Lockheed Martin Space, Littleton, Colorado, USA.

An array of conducting obstacles in a host dielectric medium modifies the constructive parameters of the composite medium. Typically, the parameters are estimated using Lorentz model. The Lorentz model predicts that an array of metallic obstacles modifies both permeability and permittivity tensors. Recently, a rigorous Floquet eigenmodal formulation was developed to analyze metamaterials. Contrary to the Lorentz model, the Floquet model predicts that the perfectly conducting obstacles modify the permittivity tensor, but do not modify the permeability tensor of the metamaterial. Interestingly, numerical results obtained from two independent full wave analyses of metamaterial-slabs support the Floquet model. In this presentation, we describe both models and examine the source of discrepancy between the models. We also discuss whether a metamaterial with negative permeability is achievable using conducting obstacles.

16.00 -16.30 Tea Break
16.30-17.30 Chipless RFID, IoT, and 5G and Beyond Technologies for the 21st Century: Dr. Nemai Chandra Karmakar, Director, Monash Microwave, Antenna, RFID and Sensor Laboratory (MMARS), Director, ECSE Industry Engagement, Monash University, Australia

The post-COVID-19 21st -century era has witnessed tremendous impetus in low latency high data rate wireless communications. When people were in lockdowns, the vital means for wireless communications with video content are smartphones using 4/5G and beyond communications. Now, this tradition continues and becomes a new normal in society. The vital building blocks to support such high data rate mobile communications are ultrawideband and/or multiband RF/microwave/mm-wave transceivers, smart antennas, signal processing algorithms and digital design. The Internet of Things (IoT) plays a vital role in fluidity and transparency in data communications over the Internet. The backbone of IoT is radiofrequency identification (RFID) technology. Due to the application-specific integrated circuits (ASICs) in the RFID tag, the cost of the identification and tracking system has become formidably expensive for mass deployment. The chipless RFID, which is a technology in-between the RFID and optical barcodes, has wireless sensing capability and can shade new light in the IoT infrastructure. Microwave and mm-wave ultrawideband technologies are essential elements for chipless RFID readers, signal processing and encoding and decoding techniques. This special tutorial session will provide comprehensive details of the UWB microwave and mm-wave transceiver design, the multiple input multiple output (MIMO) smart antenna system, various chipless RFID tags and signal processing algorithms. Along with this, the 5G and beyond technologies, augmented with monolithic microwave integrated circuits (MMIC) GaAs and GAN-based phase shifters and switching elements, have accelerate the high data rate wireless communications. This tutorial presents these cutting edge technologies automation in mining, manufacturing, healthcare, border security and customs, government departments, retail and many more industries.