Microwave Office Research Articles

Обзор САПР моделирования СВЧ-устройств

The article is devoted to a brief review of modern CAD for electromagnetic modeling of microwave devices. Five major CAD systems are described in the article: FEKO, μWave Wizard, Sonnet, AWR Microwave Office, HFSS. The main methods are given for each CAD system used for simulation of microwave structures and the main advantages that distinguish its use.

Design and Simulation of Microstrip Bandpass Filter with Regular Slots

This paper presents new microstrip slotted patch resonator bandpass filter with two transmission zeros of output frequency response around design frequency. The proposed filter uses dual-mode (doubly tuned) patch microstrip resonator with regular slots. It has a small surface area and narrower frequency response as compared with single-mode resonators. The filter is simulated by Microwave office 2015 software package at a center frequency of 2.009 GHz. The adopted substrate constant and thickness specification are 10.8 and 1.27 mm, respectively using RT/ Duroid 6010.8 material. Simulation results show that the suggested filter presents interesting frequency responses in addition to smallness properties due its high dielectric constant selection and its miniature surface area. These features represent the appealing features of the latest wireless applications.

The research of the temperature difference effect on the sensitivity of the LNA parameters

There is an investigation of the functional characteristics changes of a low noise amplifier under the influence of temperature changes with helping of a mathematical modelling in particular CAD AWRDE Microwave Office. The relative changes of the functional characteristics of electrical parameters of a low noise amplifier at the fixed frequency as a result of influence of the environment temperature are researching. As a result, temperature changes have a greater impact on the reflection coefficient than on the noise figure and gain.

Design of a High Linearity 6-GHz Class-F Radio Frequency Power Amplifier

In this study, a high linearity class-F RF power amplifier is introduced. It is designed to operate at a frequency of 6 GHz with a bandwidth of 400MHz. The amplifier mixes between the characteristics of conventional switch mode class-F and class B amplifiers. It is biased at very low quiescent power, thus it dissipates negligible DC power in the absence of RF excitation. This makes it suitable for handset applications. The amplifier is designed and tested on Microwave Office Environments. It showed linear input/output characteristics for an input RF power range of -20 to 5d Bm. The amplifier collector efficiency is 80%, which is greater than that of ideal class-B power amplifier. In addition, it is sensitive to amplify low level RF signals, therefore it needs no preamplifier.

Investigation of New Microstrip Bandpass Filter Based on Patch Resonator with Geometrical Fractal Slot.

A compact dual-mode microstrip bandpass filter using geometrical slot is presented in this paper. The adopted geometrical slot is based on first iteration of Cantor square fractal curve. This filter has the benefits of possessing narrower and sharper frequency responses as compared to microstrip filters that use single mode resonators and traditional dual-mode square patch resonators. The filter has been modeled and demonstrated by Microwave Office EM simulator designed at a resonant frequency of 2 GHz using a substrate of εr = 10.8 and thickness of h = 1.27 mm. The output simulated results of the proposed filter exhibit 22 dB return loss, 0.1678 dB insertion loss and 12 MHz bandwidth in the passband region. In addition to the narrow band gained, miniaturization properties as well as weakened spurious frequency responses and blocked second harmonic frequency in out of band regions have been acquired. Filter parameters including insertion loss, return loss, bandwidth, coupling coefficient and external quality factor have been compared with different values of perturbation dimension (d). Also, a full comparative study of this filter as compared with traditional square patch filter has been considered.

New Compact Microstrip Patch Antennas: Design and Simulation Results

Objectives: To design new multi-band antennas based on patch resonator with comparative results to each other. Both antennas are compact in size and have high quality responses which can be applied in many handheld and personal communication devices. Methods/Analysis: New microstrip patch antennas based on modified first iteration of Minkowski fractal geometry and applying central small square cut in the main resonator have been presented in this paper with and without inserting corner square patches. Both antennas have designed using single layer and dual feeds to operate as multi frequency devices. The antennas have been modeled and optimized by using the Microwave Office (MWO) simulator based on the method of moments. The projected antennas have been designed using FR4 substrate with a relative dielectric constant of 4.4 and a substrate height of 1.6 mm. Compared with the microstrip patch antenna without inserting corner patches using same main patch resonator dimensions and substrate specifications, the designed antenna with corner patches exhibits more operational frequencies as well as as greater frequency ratios with respect to the first fundamental frequency. Findings: New microstrip antennas based on patch resonator with and without inserting corner patches have been proposed. The first antenna exhibits multi-frequency behavior, where resonances appear to take place at frequencies of 2.49, 3.03and 6.63 GHz, within 2 to 7 GHz frequency range. The second antenna exhibits a higher number of resonant frequencies that appear at 2.14, 2.55, 5.03, 5.81, 5.9 and 6.14 GHz respectively under same previous frequency range. The first three operational frequencies have decreased or shifted by inserting corner square patches due to increased electrical physical dimensions of the second antenna. Also, these corner patches act as EM perturbation elements to stimulate the second antenna with more resonant frequencies within 2-7 GHz frequency sweeping range. Theoretically, there is an important relation between antenna dimensions and guided wavelength. This relation specifies if antenna dimension is less than quarter guided wavelength (λg), then the antenna is impractical because radiation resistance, bandwidth and gain are decreased and therefore the antenna size is enlarged. By the way, the dimensions of Antennas 1and 2 have been found to be (0.259 λg x 0.259 λg) and (0.269 λg x 0.269 λg) respectively according to their fundamental frequencies which are satisfactory. Both antennas have small sizes and high quality responses which can be applied in many handheld and personal communication devices. Novelty/Improvement: In this paper, new multi-band antennas based on patch resonator have been proposed. The proposed resonators have been initiated from the transformed version of the first iteration of Minkowski fractal geometry. These antennas have compact dimensions with good return loss and radiation pattern performances which are desired features to be adopted in many communication devices

Design and Simulation of 1.5GHz Amplifier Utilizing the BFR92A and Transmission Lines

The key factor of providing good performance for any electronic device is by eliminating unwanted reflections those lead to waste energy and, therefore, affect circuit stability. This is done by finding an approach to match both of the circuit’s input and output to other in-between connected elements. Amplifiers fall within this category, in this paper, our target is to match the BFR92A transistor to 50ohms input and output loads to achieve 11dB gain at 1.5GHz with 100MHz of bandwidth that it can be used for RF low noise amplifiers. In this research, different approaches were used to utilize and achieve our work requirements by, primarily, using Micro-Wave Office software (M.W.O) to calculate S-Parameters and simulate the amplifier performance. In the first design approach, intermediate line and quarter-wave plate have been used and the results are accurately discussed. Another way to design was by utilizing the stub lines to get preferring gain and bandwidth and, then, comparison has made between both approach’s results to examine which is better to use.

Design and Performance Investigation of a New Distributed Amplifier Architecture for 40 and 100 Gb/s Optical Receivers

The design of distributed amplifiers (DAs) is one of the challenging aspects in emerging ultra high bit rate optical communication systems. This is especially important when implementation in submicron silicon complementary metal oxide semiconductor (CMOS) process is considered. This work presents a novel design scheme for DAs suitable for frontend amplification in 40 and 100 Gb/s optical receivers. The goal is to achieve high flat gain and low noise figure (NF) over the ultra wideband operating bandwidth (BW). The design scheme combines shifted second tire (SST) matrix configuration with cascode amplification cell configuration and uses m-derived technique. Performance investigation of the proposed DA architecture is carried out and the results are compared with that of other DA architectures reported in the literature. The investigation covers the gain and NF spectra when the DAs are implemented in 180, 130, 90, 65 and 45 CMOS standards.The simulation results reveal that the proposed DA architecture offers the highest gain with highest degree of flatness and low NF when compared with other DA configurations. Gain-BW products of 42772 and 21137 GHz are achieved when the amplifier is designed for 40 and 100 Gb/s operation, respectively, using 45 nm CMOS standard. Thesimulation is performed using AWR Microwave Office (version 10).

Evaluation of the Equivalent Lumped Element Parameters of Modified Microstrip Ring Resonator

Microstrip ring resonator (MRR) sensor was modeled by simple equivalent lumped element circuits in free space based on simulation data obtained from Microwave Office (AWR) simulator and comparison was made with the measurements using the E5071C Network Analyzer. The calculated reflection coefficient, |G| and complex input impedanceZinusing lumped element model were compared with the measurements results. Both results showed well agreement with a little discrepancy, basically due to imperfect soldering. The MRR was designed to have operating frequencies between 0.5 GHz and 4.5 GHz. The maximum surrounding of magnetic field,Hϕis within 15 A/m in free space.

Опыт разработки высокочастотных трактов пассивной фазированной антенной решетки в виде гибридных интегральных модулей СВЧ

The article specifies the design challenges associated with the construction of phased antenna array high-frequency paths with a given amplitude-phase distribution of an average power level microwave signal. The authors propose several variants of the microstrip-based implementation of these paths. The design description for two microwave modules shows the possibility of using the integrated technology to build VHF and UHF wavelength band beam-forming antenna systems in order to reduce their mass, dimensions, production and setup costs. The article proposes what component parts could be used to build integrated phased antenna arrays. As a basic set of components used directional coupler with the right connections, providing amplitude and phase distribution of the signal by a given law. And as the substrate for the stripline is proposed to use a dielectric material with a dielectric constant greater than 10. The authors demonstrate the possibilities for the usage of state-of-the-art software to design, conduct accurate numerical simulation for and setup microwave antenna modules. The paper described in detail the calculation method of amplitude – phase characteristics of subgroups using Microwave Office software company Applied Wave Research (AWR). The calculated and experimental radiation pattern of antenna systems performed based on the developed and manufactured by the described integrated microwave modules.

RF CMOS Low Noise Amplifier Design-A Case Study

A design methodology of Differential Design of CMOS low noise amplifier (LNA) with source degeneration for Bluetooth frequency is presented. The results show that the proposed topology is effective and can be used to achieve the minimum noise figure at all frequencies of interest. This LNA was realized in 0.18μm CMOS technology using Microwave Office Tool from AWR Inc. The measured noise figure is 2.066 dB and the gain is 20.29 dB.

DESIGN AND SIMULATION OF PRINTED MICRO STRIP LOW PASS FILTER BASED ON THE ELECTROMAGNETIC MODELS 18GHZ PRINTED MICROSTRIP LOWPASS FILTER USING X-MODELS

This paper presents the Design, Simulation and characterization of Printed Micro strip Low Pass Filter based on 15 mil Alumina substrate. Simulations show a comparison between a pure EM simulation with EM Sight and a more efficient hybrid approach that combines EM analysis (using X-Models) with conventional circuit simulations and both approaches match the measured data. Furthermore, the proposed paper has four different low pass filter designs, lumped design; basic designs uses only micro strip lines; advanced design uses multiple edge coupled micro strip lines, EM sight design provides a very sharp cut-off frequency response with low insertion loss, results having great agreement with excellent correlation. Tuning and Optimization of the design is carried out using AWR Microwave office tool.

New Microstrip Bandpass Filter Designs Based on Stepped Impedance Hilbert Fractal Resonators

ABSTRACTThe proposed microstrip bandpass filters in this paper have compact sizes and narrow band responses which are the requirements of modern wireless communication circuits. These filters are constructed from dual-edge coupled resonators; each resonator is based on applying step impedance resonator generator on first and second iteration of Hilbert fractal resonators on each segment of each iteration level. They have been designed for the industrial, scientific, and medical band (ISM) band applications at a centre frequency of 2.4 GHz using a substrate with a dielectric coefficient of 9.6 and thickness of 0.508 mm. The performance of bandpass filters has been analysed using a method of moments (MoM) based on software package, Microwave Office 2009, from Advanced Wave Research Inc., which is widely adopted in microwave research and industry. Simulation responses show that these filters possess good frequency response characteristics with second harmonics suppression. Moreover, these filters showed noticeable miniaturization which is an important feature for many communication applications. The simulated and measured results are in good agreement.

Design of Magneto-Inductive Magnetic Resonance Imaging Catheters

A catheter-based RF receiver for internal magnetic resonance imaging is described. The device consists of a double-sided thin-film circuit, mounted on a hollow catheter. The system was originally designed for biliary ductal imaging, but is also potentially useful for vascular imaging. Signals are detected using a resonant L-C circuit at the catheter tip, transmitted along the catheter using an array of coupled L-C resonators, and coupled into a conventional RF system using a demountable inductive transducer. Protection against external B1 and E fields is obtained by using figure-of-eight-shaped elements with an electrical length shorter than that of an immersed half-wave dipole. Electromagnetic modeling software (AWR Microwave Office) is used to analyze a system designed for <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> H imaging at 1.5T, determine the effect of the tissue surround, demonstrate signal detection and transmission and verify intrinsic safety.

Circularly Polarized Proximity-Fed Microstrip Array Antenna for Micro Satellite

Design of circular polarization microstrip antenna array was developed to support micro-satellite technology. Circular polarization antenna array used for data transmission applications operating in the S band frequencies from the satellite to the ground station . In this study of the patch array using proximity coupling techniques in this study to obtain high gain and wide of bandwidth. The structure of the antenna array design consists of four identical square patch elements and to use the concept of corporate transmission line fed power divider network uses three transformers quarter-lambda T-junction. Bandwidth impedance matching for resonance between two patches is ¾ l antenna system for center frequency of 2.25 GHz. The antenna is designed using the method of moments through simulation with microwave office software applications. The results of simulations and measurements obtained antenna parameters, such as: bandwidth of return loss <-10 dB above 100 MHz resonant frequency shifted to 1.75%, VSWR (1 to 2), the bandwidth of axial ratio <3 dB is 1.6% (narrowband) and the maximum directivity (gain) is 9.128 dB. Overall study results showed good performance antenna array with circular polarization properties, high gain and operates in the S band frequency micro satellite system.

Design and Simulation of Cascaded Class-A Microwave Power Amplifier

Microwave power amplifiers are the most significant components in wireless communications systems. As the technology continue to progress, the designers are facing new challenges and opportunities. The purpose of this work is to push the limits of efficiency and bandwidth of power amplifiers. The objective of this research is to design and build a prototype two stage Microwave power amplifier operated at 2.4 GHz with a linear region of operation up to our desired output of 0.5 watt or 27 dBm. The transistor used in the first stage is BFP540 while the output power of the first stage is the input of the second stage in which the ATF50189 transistor is used to for amplification. All the simulations and readings are taken by using AWR Microwave Office software. By using the load line Rl and the biasing points are achieved for both stages. The applications of our proposed device include many products in the field of microwave communications. One of the important applications of a Microwave power amplifier is in the output stage of a transmitter where a signal needs amplification before it is transmitted. DOI: http://dx.doi.org/10.11591/ijece.v3i5.3644

Single-Pole Double-Throw Switches for 2.4 GHz Transceiver in Wireless Communication Applications

The aim of this paper is to present several active types of compact SPDT switches operating at 2.4 GHz and then to compare and interpret the results. An active inductor loaded switch, operating at 2.4 GHz, was designed, and then this switch was simulated with AWR Microwave Office Software, using Moment Method. A 2.4-GHz single-pole double-throw (SPDT) switch with an insertion loss of −5 dB, a 2.4 GHz SPDT switch with PIN diode having an insertion loss of −6 dB and 2.4 GHz SPDT switch with GaAs FETs with an insertion loss of −5.5 dB was implemented using 8 V. The -24 dB return loss in the pass band is the best result for GaAs FETs. So SPDT switch using FET design is better for wireless communications. The other simulation performances of the switches are summarized in the list. A good RF performance has been achieved in the designed SPDT switch based on an active switch. The proposed switch could be used for 802.11b wireless local area network applications.

Miniaturized Hybrid Rat-Race Coupler of a 2.5 GHz Loaded by Resistors

A rat-race coupler is one of the essential components used in microwave circuits. Rat-race coupler has numerous applications in satellite communication, phased array radar antenna systems and radar. Recently, wireless communication systems usually require smaller device size, in order to meet circuit miniaturization. Thus, size reduction becoming major design considerations for practical applications. This paper includes design the proposed microstrip rat-race coupler for frequency 2.5 GHz. The area of the proposed rat-race coupler compared with the conventional structure, the proposed rat-race coupler in this paper has smaller size than the conventional structure. The main outcome of this work is reducing the area of the proposed coupler by 10%. Microwave Office (MWO-225-SUF) tool is used to execute the design of the coupler in this work.

Generalized equivalent circuit model for ultra wideband antenna structure with double steps for energy scavenging

There are various types of UWB antennas can be used to scavenge energy from the air and one of them is the printed disc monopole antenna. One of the new challenges imposed on ultra wideband is the design of a generalized antenna circuit model. It is developed in order to extract the inductance and capacitance values of the UWB antennas. In this research work, the developed circuit model can be used to represent the rectangular printed disc monopole antenna with double steps. The antenna structure is simulated with CST Microwave Studio, while the circuit model is simulated with AWR Microwave Office. In order to ensure the simulation result from the circuit model is accurate, the circuit model is also simulated using Mathlab program. The developed circuit model is found to be able to depict the actual UWB antenna. Energy harvesting from environmental wirelessly is an emerging method, which forms a promising alternative to existing energy scavenging system. The developed UWB can be used to scavenge wideband energy from electromagnetic wave present in the environment.

COMPARISON OF DESIGN SOFTWARE BASED ON MODELING OF MICROSTRIP FILTERS WITH SLOTTED SCREEN

A comparative analysis of design programs Microwave Office and HFSS on examples of microstrip filters with slots in the ground plane was performed. The results of numerical modeling of the filters in comparison with experimental data are presented. Microwave Office’s advantages are an intuitive user-friendly interface and ease of development, the availability of extensive elements library which simplifies and speeds up the design process. However Microwave Office has some disadvantages: using of rectangular grid for drawing the object and time of the analysis models. The main advantages of HFSS are a high speed calculation with sufficient accuracy of the results in comparison with experiment. Using tetrahedral shape cells allows to more accurately describe the three-dimensional structures. The disadvantages of this CAD are difficulty of development and complexity of specifying ports. Thus, the system Microwave Office is better to use during the initial modeling. For more accurate results, if data about ports’ dimension are given, system HFSS is preferable.