Search

Mobile and wireless communications are playing an irreplaceable role in our daily life. 5G is highly expected and can be considered as the convergence of mobile and wireless communications. This topic becomes one of the hottest research topics recently, and papers on this topic have been paid much attention. lists the top ten papers published in the IEEE Transactions on Microwave Theory and Techniques (TMTT) in 2019 with the highest numbers of Full Text View since published. Seven papers are about millimeter-waves (mm-waves), and because mm-waves multiple-input–multiple-output (MIMO) will be adopted globally, the 24.25–27.5-GHz band and 27–29.5-GHz bands are now approved worldwide as the standard 5G communication bands. The most popular paper is published by Asbeck et al. [item 1) in the Appendix] for mm-wave power amplifiers. [ABSTRACT FROM AUTHOR]

This paper introduces a novel compact ultralightweight multiband RF energy harvester fabricated on a paper substrate. The proposed rectenna is designed to operate in all recently released LTE bands (range 0.79–0.96 GHz; 1.71–2.17 GHz; and 2.5–2.69 GHz). High compactness and ease of integration between antenna and rectifier are achieved by using a topology of nested annular slots. The proposed rectifier features an RF-to-dc conversion efficiency in the range of 5%–16% for an available input power of −20 dBm in all bands of interest, which increases up to 11%–30% at −15 dBm. The rectenna has been finally tested both in laboratory and in realistic scenarios featuring a superior performance to other state-of-the-art RF harvesters on flexible substrates. [ABSTRACT FROM PUBLISHER]

The editor reflects on the special issue of the periodical which is based on the 2012 International Microwave Symposium held on June 17-22, 2012 in Montreal, Quebec. He mentions that due to increased number of submissions to the special issue, it has been divided into two issues the first one was published in December 2012, and the next one in January 2013. He adds that the aim behind including conference papers in the issue is to present results that might help improve engineering designs.

In this paper, inkjet-printed UHF and microwave circuits fabricated on paper substrates are investigated for the first time as an approach that aims for a system-level solution for fast and ultra-low-cost mass production. First, the RF characteristics of the paper substrate are studied by using the microstrip ring resonator in order to characterize the relative permittivity (ϵτ) and loss tangent (tan δ) of the substrate at the UHF band for the first time reported. A UHF RFID tag module is then developed with the inkjet-printing technology, proving this approach could function as an enabling technology for much simpler and faster fabrication on/in paper. Simulation and well-agreed measurement results, which show very good agreement, verify a good performance of the tag module. In addition, the possibility of multilayer RF structures on a paper substrate is explored, and a multilayer patch resonator bandpass filter demonstrates the feasibility of ultra-low-cost 3-D paper-on-paper RF/wireless structures. [ABSTRACT FROM AUTHOR]

In this paper, the feasibility of inkjet printing of circuit and microwave structures on paper-based substrates is investigated for the first time in the implementation of a complete low-cost wireless platform for sensors. First, the system-level design of the module including the amplifier characterization were carried out to ensure optimum performance of the sensor modules in the UHF bands used in RF identification communication. These results were then used to design two different antenna structures, which are printed on paper along with their respective circuit layouts using inket-printing technology. Different techniques were investigated for the assembly of circuit components on the silver printed layouts. Finally, wireless link measurements on the assembled prototypes verified the good performance on the wireless and sensing sides. [ABSTRACT FROM AUTHOR]

This paper demonstrates the design of an 800-MHz solar-powered active wireless beacon composed of an antenna and an integrated oscillator on a low-cost paper substrate. Inkjet printing is used to fabricate the conductive circuit traces and the folded slot antenna, while the oscillator circuit is designed using off-the-shelf components mounted on the paper substrate. Flexible, low-cost, amorphous silicon (a-Si) solar cells are placed on top of the slot ground and provide autonomous operation of the active circuit eliminating the use of a battery. A prototype is built and characterized in terms of phase noise, radiation patterns, and the effect of solar irradiance. Such low-cost flexible circuits can find significant applications as beacon generator circuits for real-time identification and position purposes, wearable biomonitoring as well as solar-to-wireless power transfer topologies. The measured phase noise is -\116 dBc/\Hz at 1-MHz offset, while drain current is 4 mA and supply voltage is 1.8 V. [ABSTRACT FROM AUTHOR]

This paper deals with a low-cost method for the assembly of flexible substrate antennas and UHF RF identification silicon (Si) chips. Such a method exploits a magnetic coupling mechanism, thus not requiring for galvanic contacts between the Si chip and antenna itself. The magnetic coupling is established by a planar transformer, the primary and secondary windings of which are implemented on flexible substrate and Si chip, respectively. As a result, the Si chip can be assembled on the antenna with a mere placing and gluing process. First, the idea has been validated by theory. Electromagnetic simulations of a square heterogeneous transformer (1.0-mm side) show a maximum available power gain (MAG) of -0.4 dB at 868 MHz. In addition, the heterogeneous transformer is also quite tolerant with respect to misalignment between primary and secondary. An offset error of 150 \mu\ m reduces the MAG to -0.5 dB. A sub-optimal matching strategy, exploiting a simple on-chip capacitor, is then developed for antennas with 50-\Omega input impedances. Finally, the idea has been experimentally validated exploiting printed circuit board (PCB) prototypes. A PCB transformer (1.5-mm side) and a transformer rectifier (two-diode Dickson multiplier) have been fabricated and tested. Measurements indicates a MAG of -0.3 dB at 868 MHz for the transformer and the capability of the developed rectifier to supply a 220-\k\Omega load at 1.5 V with a -2-dBm input power. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes (MWNTs) are characterized at X-, Ku-, Ka-, and Q-bands by rectangular wave- guide measurements. The scattering parameters (S-parameters) of thin MWNT papers containing a large ensemble of randomly oriented nanotubes are measured by a vector network analyzer from 8 to 50 GHz. A rigorous extraction algorithm has been developed to compute the effective complex permittivity (ϵ = ϵ′ - jϵ″) and permeability (μ = μ′ - jμ″) of the nanotube papers from the measured S-parameters. The extracted effective medium parameters are verified by finite-element simulations using Ansoft's High Frequency Structure Simulator (HFSS). The uncertainties for this characterization method are analyzed. The systematic uncertainties are found larger at lower frequencies than at higher frequencies. The extracted conductivity of the nanotube papers is in the range of 810-1500 S/m and the dielectric constant is from 250 to 700. The extracted complex permittivity can be fitted with the Drude-Lorentz model for the 8-50-GHz frequency range. The effective medium theory is then applied to remove the impact of air in the nanotube paper. [ABSTRACT FROM AUTHOR]

Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers. [ABSTRACT FROM AUTHOR]

Novel 2-D gray-scale inkjet printed microstrip line (MSL) terminations are presented in this paper. The proposed open-end type MSL termination is constructed of a lossy trace printed on paper and placed on a typical dielectric substrate with background. Optimal design guidelines are also discussed for attaining best absorption band given ink resistivity and termination size. Both fixed width and tapered width lines are presented, experimentally showing high absorption levels over a wide bandwidth. These simple to fabricate structures may find applications in scenarios where low-cost wideband planar terminations are needed. [ABSTRACT FROM AUTHOR]

Presents a paper which focuses on the use of the finite-difference time-domain (FDTD) method in conjunction with the generalized pencil of function (GPOF) technique, to evaluate the reflection coefficient from shorted slotlines and coplanar waveguides, on anisotropic substrates. Identification of finite-difference time-domain solutions; Conclusions of the paper.

Focuses on the technical program presented at the 2001 Institute of Electrical and Electronics Engineers Microwave Theory and Techniques Society International Microwave Symposium in Phoenix, Arizona. Coverage of the technical program; Record on the number of paper submission; Citations on the topics in the symposium.

The 2020 Asia–Pacific Microwave Conference (APMC 2020) was held in Hong Kong, SAR, China, on December 8–11, 2020. The conference was organized by the IEEE Antennas and Propagation (AP)/Microwave Theory and Techniques (MTT) Chapter of Hong Kong, and technically co-sponsored by the IEEE MTT Society, the IEEE AP Society, the State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong; the Department of Electrical Engineering, City University of Hong Kong; and the Department of Electronic Engineering, The Chinese University of Hong Kong. Out of 531 papers submitted, 402 papers were accepted for presentation at the conference and publication in the 2020 APMC proceedings. These papers have also been published online on the IEEE Xplore website. The technical program involved more than 1000 authors coming from 28 different countries/regions. [ABSTRACT FROM AUTHOR]

The increasing use of backscatter radio for pervasive Internet-of-Things systems as a low-power and low-cost communication scheme will result in dense deployments of tags that need to operate under bandwidth (BW) constraints. Typical backscatter tags and computational radio frequency (RF) identification systems are unnecessarily limited to modulating data with “ON–OFF” switching front-ends, which leads to extensive spectrum occupancy, due to the rectangular pulses. This paper sets the foundations to overcome these limitations and proposes designs of RF front-ends that are capable of varying the tag reflection coefficient in a continuous way over time. Arbitrary waveforms can be generated to perform pulse shaping on the backscattered signals, which require significantly reduced BW. The principles presented in this paper will enable sophisticated tags to perform complex modulation schemes under BW constraints, while maintaining a very low RF front-end complexity, using a single nonlinear component such as a p-i-n diode or field-effect transistor. Migrating the idea of pulse shaping from complex power-demanding active radios to such minimal RF front-ends will complete backscatter radio as a communication scheme for simple RF tags and sensors in large-scale deployments. Each tag becomes a miniature software-defined radio that implements diverse communication schemes with increased spectral efficiency. [ABSTRACT FROM PUBLISHER]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM AUTHOR]

This article presents tips which can be used by readers to get their manuscripts published in the periodical "IEEE Transactions on Microwave Theory and Techniques," vol. 53. The author cannot overemphasize the importance of grammar and organization of ideas given by readers. Reviewers are very busy people and they were chosen because they have made important contributions to the field. Whether one is a native English speaker or not, he/she take the paper to an expert for grammatical proofreading and correction: a native-speaking English literature, history, or philosophy professor or graduate student. The readers are advised to go over the paper together with grammatical advisers.

The maximum efficiency point of an inductive power link depends on its load power consumption and the distance between the transmitter and the receiver. Matching networks (MNs) and adjustable ac–dc converters have been proposed in the literature as a means to achieve and track this maximum efficiency point. Most of the published papers in inductive power transmission only use one of these two methods without considering a joint design. In this paper, we analyze and compare both methods proposing a general joint design which exploits the advantages of each method. A proof-of-concept system was developed following the proposed flow, built and tested. This system, with a regulated output voltage, presents improvements in measured efficiencies of up to 80% (from 9.2% to 16%) at the largest distances, thus maximizing the distance range. The same approach can be used to maximize output dc voltage, instead of the link efficiency. The proposed system using our designed MN achieved a maximum output voltage that was 90% higher (from 1.36 to 2.59 V) than the case where only a step-up converter was used. [ABSTRACT FROM AUTHOR]

This paper proposes a new coupling matrix synthesis technique called the coupling matrix compression technique, which focuses on reducing the dimension of the $N+2$ coupling matrix. The presented coupling matrices can be compressed, and this technique can be used to design dual-mode resonators for high-isolation dual-band filters. One dual-mode resonator is represented as two closely coupled resonators when using this technique. The formulae for resonant frequencies and $\omega _{m}$ in dual-mode theory are also derived in this paper. A dual-mode embedded hairpin resonator is designed and analyzed using this technique, and a dual-band filter using the proposed resonators is designed and fabricated to validate the proposed technique. [ABSTRACT FROM AUTHOR]

This paper presents the design of a broadband and high-power amplifier with bounded performance technique (BPT). Like the real frequency technique (RFT) or the simplified RFT (SRFT), BPT achieves broadband performance via matching at some in-band discrete real frequencies. It solves some design issues that are not addressed in the RFT and the SRFT. Among them are the inclusion of the design specifications in the device selection and design process and the possible degradation of operation metrics that are not optimized. BPT also avoids complicated analytic mathematics by using circuit prototypes. In this paper, we show the design of an amplifier with BPT. It has a 3-dB compression power of at least 100 W and a drain efficiency of at least 50% over the band 1–2.8 GHz or 94.7% fractional bandwidth. We also show the design of the same amplifier with the traditional SRFT and compare its expected performance with that designed with BPT. [ABSTRACT FROM AUTHOR]

This paper presents an innovative experimental method for microwave power devices linearity characterization, based on a carefully designed multi-tone signal. Measurements working deeper into the understanding of in-band (IB) signal-to-noise characterization of nonlinear devices are presented. The test signal used in this paper is based on an unequally spaced multi-tone (USMT) signal, which is a tailored stimulus signal with flexible statistics. Its originality stands in its inherent property of allowing signal and intermodulation (IM) distortion separation to facilitate the derivation of the IB signal-to-noise ratio or linearity degradation, without assuming any specific modulation format. For the first time, this paper reports measurements with small $\Delta _{f}$ frequency arrangement using an USMT signal to investigate low frequencies (LFs) parasitic effect on the current and the linearity. Furthermore, this test bench allows to analyze together LF phenomena (“trapping effect”, memory effect, etc.) and high-frequency phenomena under large-signal condition with a telecom like signal. Smith chart load–pull linearity contours under wideband USMT test signals are reported for the first time. This provides a new tool to check system-level design specifications and to optimize radio frequency (RF) power amplifier structures with modulated signals. The measurements were performed using a GaN high-electron-mobility transistors (HEMT) 3-W transistor. [ABSTRACT FROM AUTHOR]

A concept of seamlessly colocated and cointegrated antennas and front-end chain circuits in the form of a unified and integrated design space is proposed, studied, and demonstrated in this paper, which strives to create future joint circuiting-radiating front-end analog functional blocks. To show the proposed concept, the building elements involving dual-function amplifier antenna are highlighted as an example and arranged in a series-connected array, each acting simultaneously as a matching circuit and transmitting antenna. In other words, a single geometrical space serves as both circuits and antennas, meaning a space overlap in which the circuit is an antenna and the antenna is a circuit. This reflects both the harmony and harmonious relationship of the circuit antenna. In this paper, the spacing between two neighboring array elements is utilized to accommodate active devices, such as transistors, in this example. As the first theoretical and experimental demonstration, this paper involves the design of patch antennas, the analysis of mutual coupling, and the placement of amplifying transistors in different operation modes. The modeling procedure for a $1 \times N$ amplifier-antenna system is presented. The proposed concept is experimentally validated by prototyping a $1 \times 2$ amplifier-antenna array at 5 GHz with rectangular patches and off-the-shell HJ-FET. An equivalent circuit network is established for the proposed dual function block. Measured results show that the experimental block has −10 dB matching bandwidth of 125 MHz at the steering angle of +30° with an amplifying gain of 11.5 dB. It is also experimentally illustrated that frequency tuning and beam steering can easily be enabled by varying the dc bias. The design of $1 \times 4$ amplifier-antenna array at 5 GHz is also discussed to generalize the proposed theory and guide the design of higher order amplifier arrays. [ABSTRACT FROM AUTHOR]

Multiarm slotline stubs have been used to increase the bandwidth of slotline open circuits in transitions between microstrip and slotline and between coplanar waveguide and slotline. The model used in prior papers is a series connection of the short-circuit terminated stubs, resulting in an increase in the input impedance by a factor of $N$ , where $N$ is the number of stubs. In this paper, it is shown that this model cannot be applied for slotline with finite width metal planes or coplanar stripline (CPS), because it does not account for higher order modes that are necessarily excited on the multiarm structure. This paper presents a physical explanation and model that accounts for the higher order modes on the structure and explains how the multiarm finite width slotline/CPS stub structure increases the bandwidth of the transitions between slotline and other transmission lines. With the correct model presented in this paper, it is expected that improved slotline or CPS circuits can be developed. [ABSTRACT FROM AUTHOR]

Over the past few years a significant growth of research involving the utilization of RF/microwave technologies in healthcare applications has been taking place. This "Special Issue on Biomedical Applications of RF/Microwave Technologies" is proof. Encouraged by funding from government agencies and private sources, and recognizing the emerging opportunities offered by high-frequency electronics and novel sensing technologies for advancing healthcare, researchers from various engineering disciplines have directed their interests to applications involving biological science and clinical medicine. The increase in RF/microwave-related activities targeting medical or biological problems is noticeable within the IEEE Microwave Theory and Techniques Society (IEEE MTT-S) community and beyond. These activities are broad in their scopes and involve multiple disciplines. They range from therapeutic, diagnostic, remote monitoring, and imaging applications of microwave technologies in clinical settings, as well as those involving sensing and communication over or through body tissues, where physiological or biochemical information are transmitted wirelessly, to the biological effects of these applications, in which the interaction of microwaves with tissues and living systems should be understood and manipulated. In addition, RF/microwave now serves as one of the key enabling technologies in innovative healthcare delivery and telemedicine. Three papers are on exposure systems for bioelectromagnetic research. Nine papers present radar-based systems for vital sign monitoring and object imaging. The remaining two radar papers focus on cancer detection by imaging. The Special Issue features papers from the US, UK, Japan, Korea, Australia, Canada, Saudi Arabia, Italy, Malaysia, Belgium, Germany, China, and France, indicating global efforts utilizing RF/microwave innovation for healthcare. [ABSTRACT FROM AUTHOR]

The article outlines the procure for the Paper Submission in Electronic Form for authors. Topics include the guidelines provided by the journal "IEEE Transactions on Microwave Theory & Techniques"; Microsoft Word is the preferred format for this final submission, page charges for traditional submissions.