Active Microwave Circuits Research Articles

Planar Mercator Smith Chart: An Alternative Approach for Active and Passive Microwave Circuits

This letter proposes a Planar Mercator Smith chart (PMSC), which can be used to design and analyze both active and passive microwave circuits on a 2-D flat surface. The entire surface of the 3-D Smith chart comprises of whole impedance plane, which includes all possible loads is projected to the 2-D flat surface of the PMSC using the mathematical principle of Mercator projection. This eliminates the need for CAD software to be used as a design tool or visualization aid unlike a 3-D Smith chart, and it may be a useful graphical chart for solving microwave problems involving any type of load.

T-Topology Coupler-Based Bandpass Negative Group Delay Active Circuit Design and Test

This article develops a design method for the bandpass negative group delay active microwave circuits. The theoretical calculations, simulation results, and measurements on a tested prototype show excellent consistency. —Haralampos Stratigopoulos, Sorbonne Université, CNRS, LIP6

Time-Efficient Adaptive Procedure for Identification of Multitone X-Parameters

A novel measurement procedure for the time-efficient identification of multitone <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> -parameters of active microwave devices and circuits is introduced. Over a given bandwidth, the procedure allows for an adaptive selection of key spectral components necessary for determining the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> -parameters characteristics with a minimum measurement effort. The sequential selection is based on the divide-and-conquer algorithm. It results in a huge reduction of the measurement time in comparison to the situation when model coefficients at all spectral components are identified. To validate the procedure, an off-the-shelf broadband power amplifier (PA) was characterized under wideband large-signal excitation conditions. Moreover, small-signal terms at all relevant frequencies were collected as a reference and compared with the results provided by a time-efficient adaptive procedure (TEAP). The proposed method resulted in twenty times reduction in the number of samples required to characterize the PA. As an application example, the small-signal coefficients identified with the TEAP are used to correct characterization results for the measurement instrument’s output mismatch. The mismatch-corrected output signal of the PA under test was represented accurately with the error-vector-magnitude of only 0.132%.

Analysis of Conditional Stability and Unconditional Stability and Instability for Microwave 3-Ports

A full and rigorous treatment of conditional and unconditional stability and instability for an active 3-port microwave circuit, represented at a given frequency by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S$ </tex-math></inline-formula> -parameters, is carried out. By terminating a given port with a variable termination one may study at the input and the output of the resulting 2-port circuit the occurrence of unconditional stability and instability, as well as of special cases of conditional stability, defined as reactive unconditional stability or instability. Such conditions are especially relevant in microwave oscillator design and were exhaustively identified for the first time and treated in previous analysis by the authors. Drawing from its conclusions, one obtains in the plane of the variable termination and with a simple algorithm, a single parametric representation, providing at once, in a closed and direct form, the entire collection of boundaries of the regions, wherein the listed conditions occur at ports of the resulting 2-port circuit. Guidelines for the design of microwave amplifiers and oscillators, both in series and shunt configuration, are sketched. Numerical examples, validated by simulations, are also presented.

A novel design of a reconfigurable power divider with stubs for mobile applications

&lt;p&gt;&lt;span&gt;Nowadays, the world knows a huge revolution in telecommunications, which has led to the need to integrate many services, such as long-term evolution (LTE), 5G, wireless local area network (WLAN), and Bluetooth, in one receiving and transmitting device. In the same way, all active and passive microwave circuits must be compatible with the integration of services, including the power divider, which is the subject of our work. This passive component is used in several fields such as medicine, surveillance, radar systems and others applications. Wilkinson divider is one of the most prominent power dividers, it is classified as narrow-band power divider and it is a very useful component in mobile applications (2.4 and 5.8 GHz). In this work, a reconfigurable 4-ports Wilkinson divider is designed using PIN diodes and simulated using connected speech test (CST) simulator software. This designed divider can easily modify the operation mode by activating or disabling the PIN diodes.&lt;/span&gt;&lt;/p&gt;

Integrated 10-GHz Graphene FET Amplifier

Graphene has unique electrical and mechanical properties which can pave the way for new types of devices for microwave applications. However, emerging technologies often have problems with yield and still considerable variation in device parameters cause great challenges for circuit design. In this paper, we present the design and development of an integrated graphene FET amplifier addressing this challenge. A representative graphene FET was selected from a set of devices and then the input and output matching circuits were designed using the negative-image technique. The two-finger GFET with a gate length of 0.5 μm exhibit a typical f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> and f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> of 35 GHz and 37 GHz, respectively. The integrated graphene FET amplifier was fabricated on a high-resistivity silicon substrate together with thin film capacitors, airbridges, and spiral inductors. A record high gain of 4.2dB at 10.6GHz was measured for a single transistor amplifier stage and agrees well with simulations. These results indicate significant progress towards active microwave circuits based on emerging 2D materials.

АВТОМАТИЗИРОВАННЫЙ СТРУКТУРНО-ПАРАМЕТРИЧЕСКИЙ СИНТЕЗ СТУПЕНЧАТОГО НАПРАВЛЕННОГО ОТВЕТВИТЕЛЯ НА СВЯЗАННЫХ ЛИНИЯХ НА ОСНОВЕ ГЕНЕТИЧЕСКОГО АЛГОРИТМА

An automated approach to the structural-parametric synthesis of a stepped directional coupleron connected lines based on a genetic algorithm (GA) is described, which makes it possible tocreate an algorithmic environment in the field of genetic search for solving NP complete problems,in particular, the structural-parametric synthesis of a stepped directional coupler on connectedlines. The purpose of this work is to find ways of structural-parametric synthesis of a stepped directionalcoupler on coupled lines based on the bionspiration theory. The scientific novelty lies inthe development of a modified genetic algorithm for automated structural-parametric synthesis ofa stepped directional coupler on connected lines. The problem statement in this work is as follows:to optimize the synthesis of passive and active microwave circuits by using a modified GA. A fundamentaldifference from the known approaches in the use of new modified genetic structures inautomated structural-parametric synthesis, in addition, a new method for calculating a steppeddirectional coupler on connected lines based on a modified GA is righteous in the work. Thus, theproblem of creating methods, algorithms and software for automated structural synthesis of microwavemodules is currently of particular relevance. Its solution will improve the quality characteristicsof the designed devices, reduce design time and costs, and reduce the requirements fordeveloper qualifications.

ТЕОРИЯ ГАРМОНИЧЕСКОГО БАЛАНСА ДЛЯ СХЕМОТЕХНИЧЕСКОГО ПРОЕКТИРОВАНИЯ

The analysis and generalization of the main publications on the methods of synthesis and analysis of non-linear active microwave circuits based on the use of the harmonic balance method are presented. As a result of some classification of mathematical approaches and techniques used in the context of this method, a selection and review of basic algorithms was made, the sequential application of which makes it possible to obtain the final result for a scheme of any complexity. The principles of drawing up the initial system of differential equations for electronic circuits and reducing it to a system of linear algebraic equations are considered. A detailed and, at the same time, simplified interpretation of the approaches involving the use of projection methods and Krylov subspaces is given in order to make them easier to understand. Both the complete and the restart generalized method of minimal residuals are considered, in which the desired solution is obtained in the course of an iterative process, at each stage of which subspaces of lower dimension are constructed. The possibilities of simulators and application packages intended for circuit design of electronic circuits are considered. The problem of matching a power amplifier in large signal mode using the APLAC simulator, which is NI AWR technology for designing high-frequency circuits, is discussed.

Data Transmission Analysis using MW-5000 at 5.8 GHz Frequency

&lt;p align="justify"&gt;In the recent years, the data communication system become the main type of communication in the world. The FSK modulator or demodulator is one of the part that becomes the most important part and extremely advanced with the involvement of microwave active and passive circuits. This paper presents the data transmission analysis using MW-5000 at 5.8 GHz frequency. This experiment use the microwave communication module MW-5000 that is available in electronic laboratory. From this experiment the duration taken for the transmission of data is depend on the length of sentence and the value of baud rate.&lt;/p&gt;

Circuit-based versus full-wave modelling of active microwave circuits

ABSTRACTModern full-wave computational tools enable rigorous simulations of linear parts of complex microwave circuits within minutes, taking into account all physical electromagnetic (EM) phenomena. Non-linear components and other discrete elements of the hybrid microwave circuit are then easily added within the circuit simulator. This combined full-wave and circuit-based analysis is a must in the final stages of the circuit design, although initial designs and optimisations are still faster and more comfortably done completely in the circuit-based environment, which offers real-time solutions at the expense of accuracy. However, due to insufficient information and general lack of specific case studies, practitioners still struggle when choosing an appropriate analysis method, or a component model, because different choices lead to different solutions, often with uncertain accuracy and unexplained discrepancies arising between the simulations and measurements. We here design a reconfigurable power amplifier, as a case study, using both circuit-based solver and a full-wave EM solver. We compare numerical simulations with measurements on the manufactured prototypes, discussing the obtained differences, pointing out the importance of measured parameters de-embedding, appropriate modelling of discrete components and giving specific recipes for good modelling practices.

Applications of Dispersion-Engineered Composite Right-/Left-Handed Transmission Line Stubs for Microwave Active Circuits

Applications of Dispersion-Engineered Composite Right-/Left-Handed Transmission Line Stubs for Microwave Active Circuits

Single-conductor co-planar quasi-symmetry unequal power divider based on spoof surface plasmon polaritons of bow-tie cells

In this paper, the spoof surface plasmon polaritons (SSPPs) transmission line (TL) of periodical grooved bow-tie cells is proposed. The complex propagation constant and characteristic impedance of the SSPPs TLs and microstrip lines (MLs) are extracted using the analytical method of generalized lossy TL theory. The properties of the SSPPs TLs with different substrates and the same geometrical configuration are experimented. Then, for comparison, two ML counterparts are also experimented, which shows that the SSPPs TL is less sensitive to the thickness, dielectric constant and loss tangent of the chosen substrate below the cutoff frequency, compared with the ML ones. The single-conductor co-planar quasi-symmetry unequal power divider based on this SSPPs TL is presented in microwave frequencies. For experimental validation, the 0-dB, 2-dB, and 5-dB power dividers are designed, fabricated, and measured. Both simulated and measured results verify that the unequal power divider is a flexible option, which offers massive advantages including single-conductor co-planar quasi-symmetry structures, wide-band operation, and convenient implementations of different power-dividing ratios. Hence, it can be expected that the proposed unequal power dividers will inspire further researches on SSPPs for future design of novel planar passive and active microwave components, circuits and systems.

On the development of a novel high VSWR programmable impedance tuner

Impedance tuners are key instruments used for load- and source–pull measurements. They are crucial for any active microwave components, circuits, and systems characterization and optimization. This paper reports theoretical, simulated, and experimental results related to the development of a novel programmable impedance tuner offering high-voltage standing wave ratio (VSWR). After presenting the proposed tuner principle, a fabricated prototype operating at microwave frequencies and based on a 3.5 mm coaxial line is introduced with experimental results. Depending on the targeted frequency band, different pairs of slugs, with optimized length and characteristic impedance, can be used to obtain an optimal VSWR. This first prototype allowed us to demonstrate the interest of the proposed impedance synthesis principle and to identify ways forward to further improve its performances and push forward this promising technology.

Design and characterization of a resonator-based metamaterial and its sensor application using microstrip technology

Design of a metamaterial based on an S-shaped resonator surrounded by a ground frame and excited by using a feeding transmission line on microstrip technology is presented. Since the resonator, ground frame, and its excitation mechanism are all realized on a microstrip, its characterization can be carried out using common laboratory equipment without needing any waveguide components or plane-wave-illumination techniques. The structure presented here may be realized on any microstrip and does not require special materials. The resonator and ground frame are both on the same side of the microstrip, thus the proposed topology may also be populated with active and passive microwave components, and hybrid active, passive, or reconfigurable microwave circuits may be realized. In metamaterial designs that require plane wave illumination, usually many numbers of periodic unit cells are needed; however, in our design, only one cell is capable of achieving metamaterial properties. The constitutive parameters of the metamaterial are retrieved and compared to demonstrate the agreement between simulations and measurements. The proposed topology is also demonstrated in a sensor application, where simulated and measured results agree well. Thus, it can be realized using standard microwave technology and used for numerous applications where metamaterial properties are needed.

RF Engineering Meets Optoelectronics: Progress in Integrated Microwave Photonics

Integrated microwave photonics (IMWP) is concerned with applying integrated photonics technology to microwave photonic systems. It is one of the most active and exciting areas of current research and development in microwave photonics (MWP), building upon the impressive foundations of integrated photonics in various systems involving material platforms such as indium phosphide (InP) and silicon nitride (Si3N4). The aim of this article is to explain to the wider microwave engineering community the significance of the new field of IMWP and to describe how it may potentially be applied to improve the performance and capabilities of microwave and millimeter-wave (mmWave) systems. Just as the microwave monolithic integrated circuit (MMIC) has revolutionized active microwave circuits, IMWP is poised to open up new applications for microwave engineering that take advantage of the unique functionalities offered by photonics, especially with regard to its large bandwidth.

Synthesis of matching networks for microwave active circuits based on genetic algorithm

ABSTRACTA new genetic algorithm‐based technique for the synthesis of broadband matching and compensation networks used in microwave active circuits is presented. It allows the complete control over network configurations and element values leading to convenient practical solutions. The technique is implemented in the software tool GENESYN. As an example, the design of interstage network that compensates the transistors' gain slope and simultaneously provides DC bias in 4–6 GHz two‐stage FET amplifier is demonstrated. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2719–2722, 2014

Analysis of Wire-Bonded Multiconductor Transmission-Line-Based Stubs

Wire-bonded multiconductor transmission lines (MTLs) can be used as shunt stubs as a way of overcoming the limitations regarding impedance levels and frequency response of single transmission-line (TL) stubs. The wire-bonded MTL is a particular case that provides greater bandwidth by eliminating high-frequency undesired resonances. In this paper, a general analysis of the behavior of this structure is presented. The performance of all eight possible configurations and an arbitrary number of strips is assessed and some physical insight into their frequency behavior is provided. Six of them allow the implementation of shunt stubs with impedance levels that are complicated or unapproachable with a single stub, while the other two provide additional degrees of freedom that are of interest for the design of filtering structures. The usefulness and validity of the proposed analytical design equations are illustrated by designing, manufacturing, and measuring two artificial TLs with left-handed bandpass response and improved out-of-band rejection. The excellent agreement between the designed and experimental results suggests that the presented analytical equations are most convenient for a quick and reliable design of many passive and active microwave circuits.

Nonlinear Simulation Methods for Active Microwave Circuits: A Review of the Art and Novel Trends

This paper discusses in detail, two techniques for the analysis of non-linearelectronic circuit. The first technique is an automated version of thetraditional time domain solution method (Transient Analysis). For a givencircuit topology the state equations are generated by computer and solvednumerically. The second technique involves the use of a hybrid timefrequencydomain approach and is known as harmonic balance (Steady StateAnalysis). The formulation and solution methods adopted for both methodsare outlined in detail. Emphasis is placed throughout an application tomicrowave circuits. In order to illustrate the properties of each method,sample analyses for two main circuits are given. The first circuit is that of alinear amplifier operating at 12 GHz and driven into saturation. The secondcircuit is that of a nonlinear frequency doubler, doubling from 7-14 GHz.Some advanced applications are discussed in order to further highlight therelative advantages and disadvantages of each technique. Finally it is shownhow a non-linear CAD package can be produced which allows circuitoptimization in a similar way to that allowed by linear CAD programs.Some remaining problems which need more investigations and possiblefuture work are highlighted.

Looking Back at Monolithic Microwave Integrated Circuits

The historical progression of the artifacts has mirrored the evolution of the MMIC field.A monolithic microwave integrated circuit is an active or passive microwave circuit formed in situ on a semiconductor substrate by a combination of deposition techniques including diffusion, evaporation, epitaxy, implantation and other means. It is appropriate to note that the raison d'etre for this technology was to fulfill the following objectives: 1) low cost, 2) reliability and reproducibility, 3) small size and weight, 4) circuit design flexibility and multifunction capabilities, and 5) multioctave performance.

An FET-based microwave active circuit with dual-band negative group delay

Recent studies proved that certain electronic active circuits are capable to exhibit simultaneously a negative group delay (NGD) and amplification in microwave frequency bands. One of the simplest topologies generating this counterintuitive NGD function effect is formed by a series RLC-network in cascade with a transistor. By using this cell, similar to the classical electronic functions, dual-band NGD microwave devices with loss compensation possibility can be designed. Theoretic demonstrations concerning the theory of the NGD circuit considered are presented. The dual-band NGD concept feasibility is concretely illustrated by an example of EM/circuit co-simulations. So, in frequency domain, dual-band NGD with minimal values of about -1 ns was observed simultaneously within two frequency bands centered at about 1.05 GHz and 2.05 GHz. To highlight the functioning of the hybrid device considered, time-domain analysis showing the RF/microwave signal advancement is performed. As application, the concept investigated can be envisaged for data synchronization in multi-channel wireless communication systems eventually degraded by undesired EMI effects.