Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

This work introduces a compact, flexible, and conformal F-slot monopole antenna for detecting cancer in human arm. This put forward antenna is composed of two flexible materials. One material is denim with a dimension 10 × 10 mm2and the other is felt with a dimension 10 × 15 mm2. The structure is integrated with six metamaterial unit cells to enhance its gain, directivity and bandwidth throughout the operating band. The proposed antenna operates over 5.6 - 58.6 GHz with return loss greater than 10 dB. The antenna attains maximum gain of 6 dBi at 43 GHz. The antenna is further attached to a human arm phantom developed in the simulator for obtaining the required signals for imaging a cancerous tissue embedded in the skin layer of the designed phantom. © 2022 IEEE.

World University root node

Department of Electrical Engineering

2022 IEEE Microwaves, Antennas, and Propagation Conference, MAPCON 2022

Wearable, Conformal, Compact and Flexible F-Slot Monopole Antenna on Textile for Non - Invasive Biomedical Imaging

This paper presents two novel miniaturized substrate integrated waveguide (SIW) cavity-backed slot antennas (CBSAs) with multiband and broadband characteristics. The first antenna combines the modified non-resonant rectangular slot with two pairs of symmetrically placed shorting pins and fed with tapered coplanar waveguide (CPW) to SIW transition for obtaining three resonances at 8.8, 12.25, and 14.35 GHz. The 10 dB return loss bandwidths (BWs) correspond to three resonances are 4.78, 3.11, and 1.82 % with peak realized gain of 6.41, 6.31, and 7.26 dBi respectively. Later for the second antenna, an indigenous method of splitting the SIW cavity is incorporated using shorting vias to obtain broadband impedance matching. Lower and high order modes (half TE110 and TE210) of the SIW cavity are coupled together to achieve broad BW with S11 <-10 dB from 12.34-14.54 GHz (16.4 %) and a flat gain > 6.4 dBi over the operating range. © 2022 European Association for Antennas and Propagation.

2022 16th European Conference on Antennas and Propagation, EuCAP 2022

Substrate Integrated Waveguide Based Compact Multiband and Broadband Antennas at X / Ku-Bands

This paper presents a novel self-decoupled 10-element multiple input and multiple output (MIMO) antenna for mobile terminal applications. High isolation between the elements is achieved by using a novel pattern diversity technique. Overall MIMO consists of two antennas of type A, four antennas of type B, and four antennas of type C, with each one, operating at 5.5 GHz. Antennas-A, B, and C are of slotted pattern, arranged in the system circuit board and two small substrates. The two small substrates having dimensions of 7.4 mm × 150 mm are vertically placed along the long side edges of the system circuit board. The overall size of the system ground plane is assumed to be 150 mm x 75 mm. The designed MIMO antenna is suitable for 5.5 GHz WiMAX operation at the mobile terminal. The MIMO elements show isolation> 15 dB over the common bandwidth (BW) of three antennas i.e. between 5.37-5.7 GHz (5.9 %) with VSWR is 3:1. © 2022 The Institute of Electronics Information and Communication Engineers (IEICE) of Japan.

Asia-Pacific Microwave Conference Proceedings, APMC

Novel Self Isolated Multiple Input and Multiple Output Antenna Using Pattern Diversity Method for 5.5 GHz WiMAX Application

This work describes a compact Double Ridge Conical Horn (DRCH) antenna utilized for ultra-wideband (UWB) Microwave Imaging (MI) applications. The proposed DRCH is appended with a dielectric lens to improve its radiation performance. The proposed antenna achieves a bandwidth from 3.4 GHz to around 20 GHz with good impedance matching. The designed antenna attains a peak gain of 25.22 dBi at 19 GHz. The applicability of the proposed antenna for microwave imaging applications is tested by checking its Specific Absorption Rate (SAR) value. Finally, the proposed antenna is used to image breast tumours in a planar breast phantom with a reduced Delay and Sum (DAS) algorithm. © 2022 IEEE.

2022 IEEE Wireless Antenna and Microwave Symposium, WAMS 2022

Double Ridge Conical Horn Antenna with Dielectric Loading for Microwave Imaging of Human Breast

In this work, a multi band Planar Inverted F Antenna (PIFA) is introduced for wireless communication applications. Initially a basic PIFA is designed. This is followed by extensive modifications to obtain five different bands namely 0.76 - 0.81 GHz, 1.01 - 1.02 GHz, 1.59 - 1.61 GHz, 1.85 - 1.95 GHz and 2.56 - 2.76 GHz. The designed antenna is tested next on human head phantom by finding the specific absorption rate (SAR) value. The obtained SAR values complies both with the American and European standards proving that the proposed antenna can be utilized for communication applications. © 2022 IEEE.

Penta-band Planar Inverted F Antenna for Wireless Communication Applications

This paper presents a broadband miniaturized Fabry-Perot cavity resonator antenna (CRA) made of novel electromagnetic bandgap (EBG) superstrate as partially reflecting surface (PRS) and reactive impedance surface (RIS) backed rectangular patch antenna. To the best of the authors' knowledge, the proposed EBG exhibits the highest stopband bandwidth (BW) with a bandgap existing between 7.37 and 12.4 GHz (50.9%). Frequency-selective property of the EBG is utilized under plane wave incidence to demonstrate it as PRS superstrate in CRA antenna. The cavity is excited with a rectangular microstrip antenna which is made of two dielectric substrates with an additional RIS layer sandwiched between them. The RIS provides wideband impedance matching of the primary feed antenna. A 7 × 7 array of the EBG superstrate is loaded over the patch antenna having an overall lateral dimension of only 45 × 45 mm2 or 1.62 λ0 × 1.62 λ0 where λ0 is the free space wavelength at the center frequency of 10.8 GHz. The proposed Fabry-Perot CRA (FP-CRA) achieves gain enhancement of 6.59 dB as compared with the reference antenna and has a 10 dB return loss BW of 23.79% from 10.07 to 12.79 GHz. A prototype of the FP-CRA is fabricated and experimentally tested with single and dual layers of EBG superstrate. Measured results show BWs of 21.5 and 24.8% for the two cases with peak realized gain of 12.05 and 14.3 dBi, respectively. Later a four-element antenna array with corporate feeding is designed as the primary feed of the CRA. The simulation result shows a flat gain of >13 dBi with gain variation <1.2 dB over the impedance BW of 13.2%. Copyright © The Author(s), 2022. Published by Cambridge University Press in association with the European Microwave Association.

International Journal of Microwave and Wireless Technologies

Broadband high gain cavity resonator antenna using planar electromagnetic bandgap (EBG) superstrate

This Chapter presents micromachined resonator and its applications in Radio Frequency (RF) circuits. A wide range of topics and prior work related to MEMS resonators are covered to provide readers with a better understanding up to a reasonable extent. Initially, operating principles of the MEMS resonators and their properties are discussed. Primary modes of the resonators are discussed that includes flexural modes, bulk modes, shear modes and torsional modes. It then discusses three different transduction techniques like capacitive, piezoelectric and piezoresistive. Different challenges behind the manufacturing of MEMS resonators are also discussed. Finally, emerging applications of MEMS resonators, namely their use in timing, sensing and radio-frequency systems are described. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Micromachined Circuits and Devices

Micromachined Resonators and Circuits

This communication presents the miniaturized low-profile second-order (SO) bandstop frequency selective surfaces (FSSs) for single- and dual-band resonances. The unit cell comprises two identical first-order (FO) elements in a back-to-back configuration with the metal grid in between. Two thin dielectric substrates separate the three metal layers. The proposed FO unit cell consists of intercell-connected spiral resonators (SRs) with capacitively coupled cross loop dipole. The SO filter response of the proposed FSS exhibits a wide stopband ( S21 < -10 dB) bandwidth (BW) of 27.6%. The unit cell has the periodicity of 0.162λ0, where λ0 is the free space wavelength at the lower passband. The novelty of the proposed work is a miniaturized simple unit cell geometry, at the millimeter-waveband but not limited to it, with polarization insensitive and high angular stable filter response up to 60° with small variations in the BW. An unconventional four-unit cell element FSS is designed for dual-band SO stopband resonances with the BWs of 8.3% and 13.8%. Prototypes of both FSSs were fabricated and their measured results were found consistent with the simulated filter responses. © 1963-2012 IEEE.

IEEE Transactions on Antennas and Propagation

Second-Order, Single-Band and Dual-Band Bandstop Frequency Selective Surfaces at Millimeter Wave Regime

This Chapter presents radio frequency (RF) micro-electromechanical system (MEMS) based compact, high power and reliable tunable bandpass filter for millimetre wave RF front end. The design is fabricated on 635 µm alumina substrate using surface micromachining process. All functional building blocks of the filter are fabricated and tested independently to ensure the optimum filter performances. Total area of the filter is only 2.3 mm2 including bias lines and pads. The proposed filter can be tuned to any frequency between 27–29 GHz, and it demonstrates insertion loss of 1.92 dB and matching of 23.4 dB at 28 GHz with fractional bandwidth of 6.7%. Filter also gives bandwidth tuning of 4.4 GHz with acceptable loss. A complete set of MEMS based tunable bandpass filter design guidelines are given for the readers. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Micromachined Tunable Filters Using MEMS Switches

A radio frequency micromachined based phase shifter is one of the key components in a modern electronically steerable phased array for satellite communication, radar systems and high precision instrumentation. The phase shifter controls the signal phase to steer the direction of the beam. MEMS technology provides a superior performance in terms of low loss, low power consumption and excellent linearity compared to other technologies. MEMS based digital phase shifters provide a large phase shift and low sensitivity to electrical noise with a high tuning ratio compared to analog versions. This Chapter describes different types of TTDTrue-time-delayPhotoresist phase shifters utilizing MEMS switches and MEMS varactors. A gold-based surface micromachining process is used to develop different kinds of MEMS phase shifters on alumina (εr = 9.8) substrates. All phase shifters are implemented using coplanar waveguide (CPW) transmission lines and actuated by electrostatic actuations. These include the analog type Distributed MEMS Transmission LineDistributed MEMS transmission line (DMTL) phase shifter using push–pull actuation, a 5-bit DMTL phase shifter using MEMS bridge and a fixed capacitor, 5-bit switched line phase shifter using DC-contact MEMS switches and a 2-bit &amp; 5-bit phase shifter using MEMS SP4T and SPDT switches. This Chapter includes details on the design, development, and characterization of MEMS phase shifters. Furthermore, all experimental results are validated with a circuit analysis and full-wave EM simulation. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.