International Microwave Symposium Research Articles

Nano Probing for Microwave Engineers: Calculating Probe-Sample Capacitance and Charge Distribution of a Near-Field Scanning Microwave Microscope on a Nanoscale

The app described in this article was presented at the student design competition of the 2016 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium. As sponsored by Technical Committee MTT-25 on RF nanotechnology, the competition's objective was to develop user-friendly interfaces to facilitate the design and application of RF nanotechnology. To this end, the app is capable of simulating the capacitance and charge distribution of the probe-sample interaction on a nanoscale in near-field scanning microscopes, such as the scanning microwave microscope (SMM), the atomic force microscope (AFM), and the scanning tunneling microscope (STM).

A Multitude of RFID Tags: A Broadband Design for Stackable Applications

RFID technology has been a part of our lives for a number years. However, research and development are ongoing to produce novel, improved tags for higher ranges working at lower power as well as to differentiate between tags in logistic applications for conventional chip-based RFIDs. Because of such improvements in already existing infrastructures and close-proximity scenarios, the second ultrahigh-frequency (UHF) RFID student design competition was held in May in San Francisco during the 2016 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS2016).

The Sky's the Limit: A Switchable RF-MEMS Filter Design for Wireless Avionics Intracommunication

The switchable RF-microelectromechanical systems (MEMS) filter described in this article was presented as part of the student design competitions at the 2016 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium held in San Francisco in May 2016. The goal of this competition, sponsored by Technical Committee MTT-21, was to design a switchable filter to separate the industrial, scientific, and medical (i.e., ISM) band (2.4-2.5 GHz) from the wireless avionics intracommunication (WAIC) band (4.2-4.4 GHz). The upcoming availability of the 4.2-4.4 GHz band for WAIC to implement wireless connectivity inside passenger aircraft cabins provided the main motivation for this design, and the filter footprint was the most important requirement.

Different Perspectives [MicroBusiness

Reports on the author's attendance at the International Microwave Symposium (IMS) and the Women in Engineering International Leadership Conference (WIE ILC).

Smooth Moves in Power Transition: New Yagi-Uda Antenna Design for Wireless Energy

During last year?s International Microwave Symposium (IMS) in Phoenix, Arizona, the IEEE Microwave Theory and Techniques Society held its fourth Student Design Competition (SDC) in the category Wireless Energy Harvesting. Seven teams from different countries presented their designs during IEEE Microwave Week 2015.

Innovating RFID for Future Applications: A Capacitive Coupled Antenna Design for UHF RFID Application

In the 2015 International Microwave Symposium (IMS 2015) Student Design Competition (SDC) held in Phoenix, Arizona, a new challenge was introduced by the Microwave Theory and Techniques Committee for RFID Technologies (MTT-24), dealing with the topic of ultrahigh-frequency (UHF) RF identification (RFID) tag sensitivity.

Cavity Resonators Do the Trick: A Packaged Substrate Integrated Waveguide, Dual-Band Filter

The 2015 Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium in Phoenix, Arizona, played host to a total of 16 student design competitions. One of these, sponsored jointly by the MTT-12 Technical Committee on Microwave and Millimeter-Wave Packaging and Manufacturing and the MTT-8 Technical Committee on Filters and Passive Components, was based on the design of a substrate integrated waveguide (SIW) dual-band filter.

Balanced\/Unbalanced Wideband: A Wideband, Bifilar Transmission-Line Balun

This article presents the design details of a wideband, bifilar transmission-line balun submitted for the student design competition for wideband baluns held during the 2015 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS 2015) in Phoenix, Arizona, and sponsored by the MTT-17 Technical Committee on HF-VHF-UHF Technology.

Learning by Using Graphene Multilayers: An Educational App for Analyzing the Electromagnetic Absorption of a Graphene Multilayer Based on a Network Model

The app we describe in this article was presented as part of the student design competitions at the 2015 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium. The objective of our particular competition, sponsored by the MTT-25 Technical Committee on RF Nanotechnology, was to develop an app) for handheld devices or personal computers that could not only support instruction in the principles and uses of electromagnetic theory as related to RF nanotechnologies but also apply to solving design problems.

Welcome to the IMS

Discusses the activities supported by the MTT-S Society as well as the events supported by the IEEE International Microwave Symposium.

The MTT-S Historical Collection [MTT World

The at the 2014 International Microwave Symposium (IMS2014) in Tampa, Florida, USA, marked the 35th anniversary of the IEEE Microwave Theory and Techniques Society (MTT-S) Historical Collection. The collection was started and first displayed at IMS1980 in Washington, D.C. According to a report by Ted Saad: At the 15 January 1980 MTT-S Administrative Committee (AdCom) meeting in Washington, D.C., Dr. Steve Adam, the then AdCom president, gave me the task of preparing a historical exhibit for the 1980 MTT-S Symposium to be held in Washington on 28–30 May 1980. No specifications or instructions were given. The was an outgrowth of a suggestion on the part of Dr. John Horton, who for several years had proposed some type of microwave hall of fame. The collection has grown steadily over the years and now consists of more than 1000 cataloged items. At the end of 2014, there were 522 pieces of hardware, 328 books, 196 miscellaneous documents, and 14 videos. The hardware artifacts comprise; 353 tubes, including gridded types, klystrons, magnetrons and other crossed-field types, radar transmit‐ receive (T/R) tubes, and tube components; 76 subassemblies or modules, including amplifiers, oscillators, and various test equipment; 56 transmission line items, including couplers, slotted lines, variable attenuators, phase shifters, and filters; 37 individual solid-state components. Some of the artifacts are one-of-akind experimental pieces like the copper- foil-lined wooden block that was used as a waveguide coupler. Many are samples of mass quantities taken from the production line. The oldest truly microwave items are two 1932 splitanode magnetrons from Ross Kilgore of Westinghouse. The newest is a 1996 Litton mini traveling-wave tube (TWT). The books include engineering texts such as a complete 28-volume set of the MIT Radiation Laboratory (Rad Lab) series, biographies of various individuals, company histories, and manufacturers' catalogs.

Guest Editorial

The articles in this special section includes 12 papers from the 2014 IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, Tampa, FL, USA, June 1–3, 2014. The symposium is colocated with the IEEE Microwave Theory and Techniques Society (IEEE MTT-S) International Microwave Symposium (IMS) each year and is a premier symposium of the IEEE MTT-S.

Transistor Model Building for a Microwave Power Heterojunction Bipolar Transistor

This article describes the detailed development of a large-signal transistor model for a microwave power heterojunction bipolar transistor (HBT). Based on the neurospace-mapping (Neuro-SM) technique, this model uses neural networks to map a coarse model space represented by the existing model simulations onto the fine model space represented by device measurements. This article tied for first place in the Microwave Transistor Modeling Student Design Competition at the 2014 IEEE International Microwave Symposium (IMS2014) held in Tampa, Florida.

Packaged Tunable Combline Bandpass Filters

This article describes the design of a packaged tunable bandpass filter used for the Student Filter Design Competition held during the 2014 International Microwave Symposium (IMS2014) in Tampa, Florida. The focus of the 2014 competition was to demonstrate a tunable bandpass filter between two wide separated bands. The first band is 4.25-4.4 GHz, and the second band is 6.25-6.4 GHz. The tunable filter must be realized on a printed circuit board with planar and lumped surface-mounted components and required to be assembled in an open-tooled FP118118-1 package [1] securely sealed with a copper tape lid. The entire package was mounted on an evaluation board, with 50-X traces connecting the radio-frequency (RF) input and output pins to 50-X female subminiature version A (SMA) connectors. The evaluation board also had a trace that connects the dc control pin of the package to a pad on the perimeter of the evaluation board. The filter performance was measured at the SMA interfaces with a dc voltage level from 0 to 20 V to shift the passbands of the tunable bandpass filter using a varactor [Microwave Associates (M/A) Com 46H202].

Design of 1:4 Ultrawideband Hybrid Transmission-Line Balun

This article presents the 1:4 wideband balun based on transmission lines that was awarded the first prize in the Wideband Baluns Student Design Competition. The competition was held during the 2014 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS2014). It was initiated in 2011 and is sponsored by the MTT-17 Technical Coordinating Committee. The winner must implement and measure a wideband balun of his or her own design and achieve the highest possible operational frequency from at least 1 MHz (or below) while meeting the following conditions: ? female subminiature version A (SMA) connectors are used to terminate all ports ? a minimum impedance transformation ratio of two ? a maximum voltage standing wave ratio (VSWR) of 2:1 at all ports ? an insertion loss of less than 1 dB ? a common-mode rejection ratio (CMRR) of more than 25 dB ? imbalance of less than 1 dB and 2.5?.

Low-Noise Amplifier for Statistical Multiband and Multistandard Applications

The Low-Noise Amplifier (LNA) Student Design Competition has continuously evolved since its inception. Each year, students have been challenged to design an LNA with an increased emphasis on ruggedness, linearity, and broadband performance [1]-[5]. The 2014 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS2014) continued this trend by requiring students to design an LNA receiver module for statistical multiband and multistandard applications in an effort to raise awareness about the complexity and nondeterministic nature of the topic. For the first time in competition history, the measurement frequencies were not predetermined and were decided on the day of the competition by two rolls of a six-sided die, with each side representing a frequency in gigahertz. This requirement prevented students from optimizing a design for a particular set of frequencies and instead called for a design possessing linear broadband performance from 1 to 6 GHz.

A Microstrip Circuit Tool Kit App with FDTD Analysis Including Lumped Elements

At the 2014 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS2014), the Apps for MTT Student Design Contest was held,sponsored by the Microwave Field Theory (MTT-15) Technical Committee. One objective of the design contest is to take advantage of the growing computing capacity of smart handheld and mobile devices to promote their use for the computer-aided analysis and design of microwave components and circuits. With the rapid development of recent iOS and Android smart phones or pads, some advanced scientific computation programs can now be executed on these portable devices. These handy devices can also deal with microwave circuit calculations if the applications (apps) are well designed. Since these devices are always accessible, it may be more convenient for engineers and students to analyze and design microwave circuits on the phones or pads directly. Note that full-wave, three-dimensional (3-D) simulations for complicated microwave circuits usually require a large amount of memory and a central processing unit with high performance, so it may be difficult to run full-wave 3-D simulations on portable smart devices.

WebLab: A Web-Based Setup for PA Digital Predistortion and Characterization [Application Notes

The WebLab that is described here was initially motivated by the 2014 IEEE Microwave Theory and Techniques Society International Microwave Symposium's (IMS2014's) Student Design Competition on Digital Predistortion (DPD) Linearization, described in Accurate Linearization with Low-Complexity Models Using Cascaded Digital Predistortion Systems, by Barradas et. al on page 94 in this issue of IEEE Microwave Magazine. To make a comparison of DPD algorithm performance, it is necessary to have one device under test (DUT), a Doherty power amplifier (PA), and one measurement setup for everybody to use. This was not a problem for the finals of the competition because the competitors would all be physically present at the same location. However, for the preparations starting half a year in advance, this posed a serious problem. The solution we implemented takes advantage of the fact that most universities today provide a decent Internet connection for their employees and students. A remotely accessible WebLab seemed to be a viable solution to the problem of letting the competitors practice on the actual DUT using the same measurement setup before the final competition at IMS2014. We decided to construct a Web-based remote-controlled PA measurement setup that allowed any user (not only the competitors) to upload his or her own input data and download the resulting measured output data. The Web page and instructions for using it can be found at http://dpdcompetition.com.

A Compact L-Band Bandpass Filter with RF MEMS-Enabled Reconfigurable Notches for Interference Rejection in GPS Applications

In light of today's crowded radio spectrum and the high level of receiver sensitivity required to receive very weak signals, mitigating interference (cosite, intentional jamming, or from other sources) has become a very important topic of research. The recent controversy regarding the use of spectrum close to the global positioning system (GPS) bands is the motivation for the IEEE Microwave Theory and Techniques Society 2014 International Microwave Symposium (IMS2014) Tunable Radio-Frequency (RF) Microelectromechanical Systems (MEMS) Filter Student Design Competition, held in Tampa, Florida. Although there are frequency bands reserved for GPS,there is sometimes interference from undesired signals from a variety of sources, such as radio emissions in adjacent bands, intentional/unintentional jamming, and naturally occurring space weather. Ensuring the continuity of GPS service requires the protection of its spectrum from interference. This competition was intended to interest students in the design of innovative RF front-end solutions to address this issue. This article describes the work of the winners of the first-place award.

Development of a Model for a Microwave GaInP\/GaAs HBT

This article presents the development of a nonlinear model for a microwave gallium indium phosphide (GaInP)/gallium arsenide (GaAs) heterojunction bipolar transistor (HBT). This model tied for first prize in the Microwave Transistor Modeling student competition held during the 2014 IEEE Microwave Theory and Techniques Society International Microwave Symposium (IMS2014) in Tampa, Florida.