Manos Tentzeris

• PhD, University of Michigan, USA
• Professor at Georgia Institute of Technology

Internet of Things applications based on backscatter radio principles have appeared to address the limitations of high cost and high power consumption. While radio-frequency identification (RFID) sensor nodes are among the most commonly utilized state-of-the-art technologies, their range for passive implementations is typically short and well below...

A new metamaterial based, circular polarized electromagnetic energy harvester is presented in this work. The structure, which is multilayer and utilises the well-known to the literature geometry of the spiral split ring resonator, operates at the Wi-Fi frequency band. Based on full electromagnetic analysis, the proposed harvester presents high effi...

This work presents a novel tile based approach to constructing, in a modular fashion, massively scalable MIMO and phased arrays for 5G/B5G millimeter-wave smart skins and large-area reconfigurable intelligent surfaces for Smart Cities and IoT applications. A proof-of-concept 29 GHz 32 elements phased array utilizing 2×2 “8-element subarray” tiles w...

This paper presents a novel passive Schottky-diode frequency doubler equipped with an on-off keying (OOK) modulation port to be used in harmonic transponders for both identification and sensing applications. The amplitude modulation of the second-harmonic output signal is achieved by driving a low-frequency MOSFET, which modifies the dc impedance t...

A filtering push–pull power amplifier (PPPA) is presented based on the multifunctional impedance matching network (MIMN), which is constructed by coupled lines and open-circuited transmission lines. Due to the symmetry of designed MIMN, the even-and odd-mode method is employed to analyze the operating mechanisms, which reveal that designed MIMN can...

In this effort, we present a fully energy autonomous two-way repeater system for use in nonline-of-sight (NLOS) interrogation of wireless sensor networks. The proposed system is based on a pair of tunnel diode reflection amplifiers, taking advantage of the existence of a negative differential resistance region that exists when the device is biased...

Rapid advances in antennas, propagation, electromagnetics, and materials are opening new and unexplored opportunities in body area sensing and stimulation. Next-generation wearables and implants are seamlessly providing round-the-clock monitoring. In turn, numerous applications are brought forward with the potential to ultimately transform healthca...

Backscatter communication is an emerging paradigm for pervasive connectivity of low-power communication devices. Wirelessly powered backscattering wireless sensor networks (WSNs) become particularly important to meet the upcoming era of the Internet of Things (IoT), which requires the massive deployment of self-sustainable and maintenance-free low-...

Future devices for the Internet of Things will require communication systems that can deliver higher data rates at low power. Backscatter radio—in which wireless communication is achieved via reflection rather than radiation—is a low-complexity approach that requires a minimal number of active elements. However, it is typically limited to data rate...

5G has been designed for blazing fast and low-latency communications. To do so, mm-wave frequencies were adopted and allowed unprecedently high radiated power densities by the FCC. Unknowingly, the architects of 5G have, thereby, created a wireless power grid capable of powering devices at ranges far exceeding the capabilities of any existing techn...

This study presents a novel dual‐band filtering power divider (DB‐FPD) structure with independently controllable bandwidths for dual‐band application. The proposed DB‐FPD structure is constructed by shorted G‐ and T‐shaped patch resonators, and meandered slot lines are etched on shorted patch resonators to generate resonance in the upper band. The...

In this study, a series of rat‐race couplers with bandpass filtering responses and impedance transforming characteristics are presented based on novel coupled‐line structures. Firstly, a novel filtering rat‐race coupler core circuit is proposed by introducing coupled‐line structures into conventional rat‐race coupler. Then, a series of rat‐race cou...

This paper proposes an electromagnetic based planar pressure sensor using a substrate integrated waveguide (SIW). The proposed pressure sensor is inspired by a rectangular SIW cavity and is additively manufactured using 3D printed dielectric material with inkjet printed conductive pattern. Since the resonance frequency depends on the SIW centre in...

This paper proposes a novel miniaturized wearable antenna (mosaic antenna) for cross-body communication featuring a superior performance compared to five commonly utilized wearable antenna topologies. The proposed mosaic antenna optimally excites the surface waves to enable cross-body communication yet still with a low profile and a miniaturized si...

A novel differentially fed fractal antenna coated with a layer of a dielectric film and operating at two bands of Medical Implant Communication Services 402–405 MHz and Industrial, Scientific, and Medical 2.4–2.48 GHz, is investigated to enable sufficient data transmission rates, while featuring a ‘mode‐control’ signal to prolong the battery life....

Unlike conventional energy harvesters that are tuned to individual frequencies and are directional, the proposed wideband (23% fractional bandwidth), omnidirectional system harvests from all FM towers in vicinity. Hence, it does not require each sensor node to be carefully aligned to any one source and makes itself suited for mass-deployment applic...

This article presents the first time that an millimeter-wave (mm-wave) multichip module (MCM) with on-demand "smart" encapsulation has been fabricated utilizing additive manufacturing technologies. RF and dc interconnects were fabricated using inkjet printing, while the encapsulation was realized using 3-D printing. Inkjet-printed interconnects fea...

A novel compact isolation circuit (IC) is proposed for the ultracompact and wideband UHF Marchand balun topology, and exact design formulas are presented for arbitrary coupling coefficients and impedance-transforming termination impedances. The wideband Marchand balun mainly consists of two identical coupled transmission-line sections which are far...

This paper presents a new compact lightweight radio frequency (RF) energy harvesting system. The system relies on a dual-tapered transmission line-based matching network that stretches the rectification capability of an integrated Schottky diode. This topology is demonstrated on a 2.4 GHz rigid harvesting system with a resulting power conversion ef...

This paper proposes miniaturized, lightweight and high sensitivity planar metamaterial based sensors for relative permittivity measurement within [0.9-10.9] GHz band. Each proposed sensor is designed using a thin-substrate microstrip line loaded with a single complementary split ring resonator (CSRR). The loaded resonator is excited using maximum e...

A first-of-its-kind design methodology to realize thermally actuated origami-inspired multilayer Miura frequency selective surfaces (MLM-FSSs) using a polyester-based substrate is presented in this article that can change its frequency response according to the variation in its ambient temperature. In order to maintain the optimum interlayer distan...

An optically transparent metamaterial absorber that can be obtained using inkjet printing technology is proposed. In order to make the metamaterial absorber optically transparent, an inkjet printer was used to fabricate a thin conductive loop pattern. The loop pattern had a width of 0.2 mm and was located on the top surface of the metamaterial abso...

This article proposes a frequency switchable microwave resonator based on a microfluidic defected ground structure (m‐DGS) that provides wider frequency tuning ratio. Because its resonant frequency is determined from the DGS geometry, the resonant frequency can be switched by injecting EGaIn liquid metal into the m‐DGS to decrease the effective ind...

In this article, the implementation of a machine learning (ML) strategy based on neural networks for the real-time range-adaptive automatic impedance matching of wireless power transfer (WPT) applications is discussed. This approach for the effective prediction of the optimal parameters of the tunable matching network and the selection of range-ada...

In this paper, we propose a bi-directional loop antenna array using magic cube origami. The proposed antenna array consists of three one-wavelength loop antenna elements with series feeding. Each loop antenna is realized on a single magic cube, and three cubes are connected in series to form the array. The three cubes can be easily folded and unfol...

This work describes the implementation of a machine learning (ML) classification strategy for read/interrogation enhancement in chipless Radio Frequency Identification (RFID) applications. A novel ML-based approach for classification and of detection tag IDs has been presented which can perform effective transponder readings for a wide variety of r...

Nowadays, the explosive growth of Internet-of-Things-related applications has required the design of low-cost and ultra-low-power wireless sensors; backscatter communication has been introduced as a cutting-edge technology that could address the above constraints. For sensing applications, the monitoring of plant water stress is of high importance...

This work presents a high efficiency, co-planar and low-complexity RF-to-dc rectifier of one diode, which is able to be directly connected, i.e., without a matching network, to a co-planar antenna, e.g., to a dipole or loop antenna. The rectifier was designed to optimally operate at 868 MHz and for low power input. Specifically, it presents 54.82%...

The above paper claims that if each 90° transmission-line section of a conventional ring hybrid (CR) is replaced with an asymmetric T-type, the resulting circuit conserves the properties of CR in the frequencies of operation. The theorem is, however, a fundamental mistake, which will be verified further.

A novel multilayer flexible packaging fabrication process using only additively manufacturing techniques including inkjet and 3 dimensional (3D) printing is proposed. The 3D printed ramp structures and inkjet printed transmission lines on top of that are suitable for mm-wave inter-layer connections because lower parasitics are induced to the system...

In this effort, the authors demonstrate for the first time the implementation of a Rotman-Lens-based rectenna system for mm-wave harvesting, in the28 GHz band. The structure merges unique RF and DC combination techniques, for the realization of rectennas that display the unlikely combination of high gain and large beamwidth. The Rotman-lens-based r...

This paper introduces a novel additivemanufacturing technique to obtain high-resolution selective-ink-deposition on complex 3-D objects, packages, and modules for 5G applications. The technique consists of embossing the desired pattern directly on the 3-D printed dielectric surface and then applying ink with a suitable tool. This approach is tested...

The mentioned paper ( IEEE Trans. Compon., Packag., Manuf. Technol ., vol. 7, no. 6, pp. 944–955, Jun. 2017) treats rat-race couplers (ring hybrids) and branch-line hybrids, but three errors are found for the ring hybrids: missing important references, wrong design parameters, and wrong interpretation on the termination impedances, which will be c...

In this paper, a novel high-efficiency, low-cost, and low-complexity RF-to-dc converter was designed for RF energy harvesting in the 2.4-GHz band. The proposed design has two RF inputs and maintains high efficiency over a wide range of incoming incident wave angles. The circuit is based on a Wilkinson power combiner and has two single-diode rectifi...

The above paper treats a method to reduce Wilkinson-type power dividers (PDs), based on small phase delays. However, the admittance matrix [(4) in the above paper] of the suggested topology seems to be erroneous, which will be clarified further.

Three mapping functions are for the first time derived for allowed and forbidden regions of a complex impedance transformer with only one transmission-line section (TL). The divided sections of the allowed and forbidden regions are six for transforming real into complex impedances, and those for both complex termination impedances are 14, indicatin...

Coupled-line ring hybrids (CRHs) are presented for arbitrary circumferences and for arbitrary power-division ratios. They each consist of three single transmission-line sections and a set of coupled transmission-line sections with or without two identical capacitances and contain most properties of the conventional ring hybrids. Therefore, they may...

In this paper, the far-field energy harvesting system for self-sustainable wireless autonomous sensor application is presented. The proposed autonomous sensor system consists of a wireless power supplier (active antenna) and far-field energy harvesting technology-enabled autonomous battery-less sensors. The wireless power supplier converts solar po...

A branch-line hybrid (BH) topology is suggested, consisting of four equal lengths of transmission-line sections (TLs) with two different characteristic impedances and four identical L-sections with each a TL and an open stub. The topology can provide three distinct properties; lower characteristic impedances of TLs, longer electrical paths for the...

A novel Gysel power divider, which can be fabricated without a need for any high impedance transmission-line section (TL), even for the power-division ratios higher than 15 dB, is presented. To derive its design formulas, a new study on the conventional in-phase T-junctions is carried out, and two conditions are newly derived for the arbitrary powe...

This article proposes a low-loss and light 3D-printed substrate-integrated waveguide (SIW). Despite the use of lossy polylactic acid (PLA) material, insertion loss is reduced, and bandwidth is increased due to a honeycomb substrate similar to air. To demonstrate the proposed concept, we fabricated microstrip-fed SIWs with solid PLA and honeycomb su...

This paper covers examples of state-of-the-art nanotechnology-empowered materials relying on additive manufacturing techniques for the ultra-low-cost fabrication of flexible radio frequency (RF) and millimeter-wave (mm-wave) wireless electronics and sensors. First, a look into the utilization of carbon-based nanomaterial inks such as carbon nanotub...

This paper presents a new compact ultra-lightweight radio frequency (RF) energy harvester fabricated on a flexible substrate. The proposed rectenna is designed to operate over the 2.4GHz ISM band. The rectifier includes a dual transmission lines tapered matching network that provides a combination of compactness, flexibility and an efficiency of up...

This paper introduces a low‐cost, high‐performance mmWave antenna array module at 77 GHz. Conventional waveguide transitions have been replaced by 3D CPW‐microstrip transitions which are much simpler to realize. They are compatible with low‐cost substrate fabrication processes, allowing easy integration of ICs in 3D multi‐chip modules. An antenna a...

In the above paper [1] two equivalent circuits of L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> - and Htypes for a 90° transmission-line section (TL) are suggested only for N = 1. However, the design formulas for N = n, where n ≥ 1 and integer, are already published for L <sub xmlns:mml="ht...

In this article, the particular importance of nanotechnology-enabled materials associated with additive manufacturing techniques for the realization of radio-frequency (RF) components and modules for Internet of Things (IoT) and millimeter-wave (mm-wave) applications is discussed.

Significance Conventional reconfigurable electrical and radio frequency (RF) structures commonly used in applications involving real-time reconfigurability in response to fast varying operational scenarios require specialized substrates or complex electrical circuits. Origami-based RF reconfigurable components and modules offer a solution featuring...

Package-integrated and ultra-thin low-pass filter (LPF) and bandpass filter (BPF) with footprint smaller than $0.5\lambda _{0}\times 0.5\lambda _{0}\times 0.025\lambda _{0}$ at the operating frequencies of 28- and 39-GHz bands are presented for 5G and mm-wave small-cell application. Such package integration of 5G filters with ultrashort 3-D interc...

Ambient backscatter uses radio frequency signals available in the environment (e.g., radio broadcasting, television, or mobile telephony) to transmit data effectively leading to significant energy and cost efficiency increase. This paper presents a novel wireless tag, which for the first time utilizes 4-pulse amplitude modulation technique to modul...

For a frequency‐division duplex (FDD) wide‐band code‐division multiple‐access (WCDMA) system, transmit (TX) signal leakage at the receiver input degrades the receiver performance. To cancel this TX leakage, a frequency selective feedback was previously proposed, but it had an unpredictable feedback loop characteristic due to the uncertainty of the...

As modern warfare has grown increasingly reliant on mission-critical electronics over the past two decades, the United States warfighter has had to carry an increasingly heavy burden of equipment, armor, and batteries. In this study, we review the properties and potential efficacy of energy harvesting technologies across several modalities: solar,...

Wireless sensors are pervasive today for applications spanning environmental sensing, safety, health, structural integrity, smart homes, and smart cities. Implementations of wireless sensor networks and Internet of Things (IoT) systems have typically relied on power supplied by batteries, which have a limited lifetime and pose the increased burden...

In this paper, we propose a frequency-tunable electromagnetic absorber that uses the mechanical control of substrate thickness. The absorption frequency of the proposed absorber can be changed by varying the substrate thickness. In order to mechanically control the substrate thickness, we introduce a 3D-printed molding with air space. The proposed...

Nowadays, the monitoring of plant water stress is of high importance in smart agriculture. Instead of the traditional ground soil-moisture measurement, leaf sensing is a new technology, which is used for the detection of plants needing water. In this work, a novel, low-cost and low-power system for leaf sensing using a new plant backscatter sensor...

This work presents a novel wireless tag operating solely with ambient backscatter signals while featuring high-order modulation capabilities. Specifically, the proposed tag communicates with a low-cost software defined radio reader using backscatter radio principles on ambient commercial FM station signals, while sensing information from sensors ca...

In this article, we propose a low‐cost three‐dimensional (3D) printed metamaterial absorber. The proposed metamaterial consists of a periodic structure of circular truncated cones. The dielectric materials supporting the circular truncated cone are made from a poly(lactic acid) filament using the 3D printer. The conductor of the circular truncated...

This article outlines the design, processing, and implementation of inkjet and 3D printing technologies for the development of fully printed, highly integrated millimeter-wave (mm-wave) wireless packages. The materials, tools, and processes of each technology are outlined and justified for their respective purposes. Inkjet-printed 3D interconnects...