FSRFT Based broadband double matching via passband extremums determination

Fast simplified real frequency technique (FSRFT) is a numerical solver used to solve microwave broadband doublematching (DM) circuit design problems in a much faster and effective manner. Recently, it has been reported that an FSRFT based Matlab code can complete the design of a order lowpass lumped element double matching network to match a given generator and load impedance within an optimization time of only 0.6 seconds, a 47 fold less time than that of the same design done using the classical simplified real frequency technique (SRFT). FSRFT owes this superior speed performance to the fact that it tracks only (system unknowns plus 1) number of passband extremum points selected from among the number of gain data ( ). This work introduces a simple numerical technique called PED (passband extremums determination technique) to be used in determination of these passband extremum points (PEs). An exemplary order microwave bandpass DM circuit design using FSRFT based Matlab (of Mathworks Inc.) code and the simulation of this design via MWO (of AWR Corp.) has yielded the same circuit performance with an exact agreement. Thus, FSRFT, equipped with the PED, newly proposed hereby, might be used as a powerful solver in designing broadband circuits in many fields such as RF/microwave, radar, and communications.Publisher's Versio

Mixed element wideband microwave amplifier design via simplified real frequency technique

In this study, we illustrate the design and implementation of a wideband microwave small-signal amplifier composed of mixed elements. The design is based on Simplified Real Frequency Technique (SRFT). A design of low power amplifier circuit is completed and its simulations are performed in success. The circuit is designed with lumped elements, however, some of the lumped elements are converted to distributed elements for their convenience in production. In this way, a mixed element wideband microwave amplifier comprised of input/output matching networks with lumped and distributed elements has been formed. Layout work and also post layout simulation is given with satisfying results.This work is supported by RFT Research A.S., an incubator firm settled in Istanbul Teknopark A.S. campus, Istanbul/TurkeyPublisher's VersionAuthor Post Prin

Unit element bandpass filter design via simplified real frequency technique for UWB microstrip patch antenna

Design of a UWB (Ultra Wideband) microstrip patch antenna to operate in the first channel of the UWB standard and a bandpass (BP) UE (Unit Element) microstrip filter (BPUEF) for this antenna are studied and presented with promising experimental results. A typical UE BP filter is a lossless 2-port network which is formed with certain number of cascade connected commensurate transmission lines. Based on the simplified real frequency technique (SRFT) in Richards domain, driving point Darlington impedance function of the BPUEF is obtained via optimization such that optimum power transfer would be possible between a PA (power amplifier) and the antenna. Using the UE synthesis, characteristic impedance values of each UE is extracted from the input impedance function. Theoretical design (Matlab), simulation (ADS, Agilent Inc.) and the measurements are shown to be in a high degree of agreement.Publisher's VersionAuthor Post Prin

A Semi-analytic Method To Design Wideband Microwave Amplifiers

(Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013(PhD) -- İstanbul Technical University, Institute of Science and Technology, 2013Bu çalışmada, Normalleştirilmiş Kazanç Fonksiyonu (NGF: Normalized Gain Function) olarak adlandırılan yeni bir yöntem kullanılarak genişband mikrodalga yükselteç tasarımı yapılmaktadır. NGF yöntemi, literatürde çok iyi tanınan SRFT (Simplified Real Frequency Technique) yarı-analitik nümerik yöntemi ile birleştirilerek kullanılmakta, yükselteç giriş/çıkış empedans uyum devre fonksiyonları ve devreleri elde edilmektedir. Türeve-dayalı optimizasyon algoritmaları yerine fminsearch arama algoritması kullanılarak yakınsaması daima garanti edilebilir ve gerçeklenebilir empedans fonksiyonları elde edilebilmektedir. fminsearch optimizasyonuna dayalı NGF yöntemi ile SGA (Sloping Gain Amplifier) tasarımı yapılmaktadır. Tezde, bu türden bir eğik kazançlı genişband SGA yükselteç önerilmesinin nedeni SGA türü yükseltecin aynı bandda çalışan düz kazançlı genişband FGA (flat gain amplifier) yükselteç ile karşılaştırıldığında; gerek a) ortalama verimliliğinin daha yüksek, gerekse b) ?hiçbir geribesleme devresi kullanmaksızın? düşük giriş/çıkış/iç yansıma katsayılarına sahip olmasıdır. Bunun aksine, bir FGA?nın giriş ve çıkış yansıma katsayısı değerlerinin düşük elde edilebilmesi; ancak ve ancak kullanılan aktif elemana bir geribesleme uygulanması ile mümkündür. Tezde; SGA türü yükseltecin geniş bir çalışma bandında eğik bir kazanç şekline sahip olmasının, bu tür yükseltecin ?hiçbir geribeslemeye ihtiyaç duymaksızın? daha yüksek ortalama verim ve düşük giriş/çıkış/iç yansımalarına sahip bir yükselteç olarak kullanılabileceği gösterilmektedir. Ayrıca, SGA türü yükselteçlerin özellikle X bandı gibi çok yüksek frekanslarda FGA türü yükselteçlere göre daha verimli oldukları hesaplanmıştır. Bu anlamda, günümüzde halen çok sayıda dar bandlı PA (Power Amplifier) kullanmak zorunda olan tüm taşınabilir kablosuz ekipmanların (örneğin 0.8-5.2 GHz aralığında çalışan çok standardlı çok modlu cep telefonları) sadece bir adet genişbandlı SGA türü bir mikrodalga yükselteçle donatılması, esnek SDR (Yazılım Radyo, Software Defined Radio) teknolojilerine uygunluk açısından büyük önem arzetmektedir. SGA yükselteçleri geleneksel negatif geribeslemeli ve dengeli yükselteçlere göre tasarımı daha kolay, daha ucuz, daha hafif devreleri olanaklı kılmaktadır. Giriş/çıkış yansımalarını azaltmak üzere LRA (Least Reflection Approach) ve BRA (Balanced Reflection Approach) yaklaşımları önerilmekte ve kullanılmaktadır. Ayrıca, SGA türü yükseltecin genlik ve faz cevabına uygun olarak SDR birimi üzerinde Genlik ve Faz Sayısal Ön-Düzeltme Birimi (AP-DPD: Amplitude and Phase Predistortion Unit) önerilmektedir.In this work, wideband microwave amplifier designs are done using a novel methodology we call as ?NGF (Normalized Gain Function)?. NGF method is used in combination with SRFT (Simplified Real Frequency Technique) semi-analytic method, which is a very well-known numerical solver in the literature, and eventually impedance functions and corresponding circuits of input/output matching networks are obtained. Rather than using gradient-based optimization algorithms, search algorithms such as fminsearch are used to obtain optimizations which are always convergent and gives realizable immitance functions. With fminsearch-based NGF, SGA (Sloping Gain Amplifier) design can be done. The thesis proposes such a wideband SGA kind amplifier design because of its a) higher average efficiency compared to a wideband FGA (flat gain amplifier) operating in the same band and b) low input/output/internal reflectances without using any feedback network. On the contrary, it is well-known that an FGA could have low input/output reflectances if and only if it is constructed with an active device around which a feedback network is placed. In the thesis, it has been shown that having of sloping gain shape along a wide frequency band of operation makes an SGA more efficient and low (input/output) reflective without using any feedback. Calculations have showed that SGA has higher efficiency than FGA especially at very high frequencies such as X band. It is rather important to realize the output stage of a traditional mobile phone with only one such a wideband SGA instead of using a large number of narrow band amplifiers. Such wideband single SGA output topology is also very suitable to the flexible SDR (Software Defined Radio) technologies. SGA design approach allows us to obtain easier, cheaper, lighter mobile equipment than negative amplifier and balanced amplifier approaches. Furthermore, novel LRA (Least Reflection Approach) and BRA (Balanced Reflection Approach) are proposed to reduce the input/output reflections. Moreover, a unit, AP-DPD (Amplitude and Phase Predistortion), is proposed to be placed into the SDR in accordance with the amplitude and phase response of the SGA.DoktoraPh

FSRFT Based Broadband Double Matching via Passband Extremums Determination

Fast simplified real frequency technique (FSRFT) is a numerical solver used to solve microwave broadband doublematching (DM) circuit design problems in a much faster and effective manner. Recently, it has been reported that an FSRFT based Matlab code can complete the design of a order lowpass lumped element double matching network to match a given generator and load impedance within an optimization time of only 0.6 seconds, a 47 fold less time than that of the same design done using the classical simplified real frequency technique (SRFT). FSRFT owes this superior speed performance to the fact that it tracks only (system unknowns plus 1) number of passband extremum points selected from among the number of gain data ( ). This work introduces a simple numerical technique called PED (passband extremums determination technique) to be used in determination of these passband extremum points (PEs). An exemplary order microwave bandpass DM circuit design using FSRFT based Matlab (of Mathworks Inc.) code and the simulation of this design via MWO (of AWR Corp.) has yielded the same circuit performance with an exact agreement. Thus, FSRFT, equipped with the PED, newly proposed hereby, might be used as a powerful solver in designing broadband circuits in many fields such as RF/microwave, radar, and communications.Publisher's Versio

Termination transformation theorem for microwave power transfer networks

Termination transformation theorem (TTT) proposed in this work transforms a doubly complex terminated microwave power transfer network (PTN) to an equivalent doubly resistively terminated termination transformed network (TTN) which is essentially a filter network. In this work, the transducer power gain (TPG) formula, Tgen, based on S and transmission (ABCD) parameters for the PTN have been restudied from the classical literature. Then, a new TPG formula, Tgen1, based on the newly proposed TTT has been derived using the transformed TTN network. To be able to show the validity of the proposed TTT, the newly derived TPG formula Tgen1 and the classical TPG formula Tgen have been computed within the scope of an example PTN design. The theorem has been proved mathematically, and experimentally as well with the aid of a Matlab code. The performance plots yielded from the Matlab code have clearly shown that both TPG formulae, i.e., Tgen and Tgen1, are in complete agreement with each other. In that sense, the proposed TTT might be considered as an alternative and helpful technique to be used in microwave engineering.Publisher's Versio

Broadband matching of PA-To-PCB interconnection for X-band wireless power transfer

Design and simulation of a microwave wideband microstrip unit element bandpass matching network is presented, potential use might be a broadband WPT (microwave wireless power transfer) application in X-band frequencies (8-12 GHz). The source of the main energy can be wind, fossil, tidal, solar, nuclear, hydro etc. and the main energy can be converted from DC to microwave energy which then can be transmitted via the proposed WPT circuit towards a few or a network of a multiple microwave harvester receivers located at a near or far field from the main source. In the work, a bandpass matching network (BPMN) composed of microstrip "unit elements (UEs)" is designed to operate along the whole X-band (8-12 GHz). Designed BPMN is excited by an X-band commercial PA (power amplifier) MMIC (monolithic microwave integrated circuit) packaged chip, and it is loaded by an X-band microstrip patch antenna. A bond wire soldered between the RF output pad of MMIC chip and the input pad of the BPMN has an equivalent LC parasitic impedance assumed to be the generator complex impedance that must be compensated in a typical matching problem. SRFT (simplified real frequency technique) is used in the design of the matching network that compensates the effect of bond wire and very good agreement found between the theoretical design and simulations done in MWO (AWR).Publisher's Versio

FSRFT - Fast simplified real frequency technique via selective target data approach for broadband double matching

This brief introduces a broadband double-matching (DM) solver called fast simplified real frequency technique (FSRFT). FSRFT is essentially a greatly accelerated variant of the well-known classical simplified real frequency technique (SRFT). The basic idea that turns the classical SRFT into a 'fast' SRFT relies on two main approaches: the selective target data approach (STDA) and the constraint optimization approach (COA). STDA constructs an optimization target data set formed of only critically selected target data whose element number is equal to or slightly greater than the order of the system unknowns n plus 1, {n}+1. In order to exhibit speed performance comparison between SRFT and FSRFT, an example design is considered. An exemplary DM problem, dealing with an {n}=6th order low-pass Chebyshev-type equalizer design to match the given generator and load impedances, has been solved by SRFT within 29 s using 90 target data in a typical computer - e.g., Intel 2.20-GHz i7 CPU with 8-GB RAM. On the other hand, the same problem has been solved by the newly proposed FSRFT within only 0.6 s using only n+1=7 critically selected target data in the same computer. FSRFT introduced herein works in any domain, i.e., lumped, distributed, and mixed.Publisher's Versio

A method for low-pass filter designing by commensurate transmission lines

It is well known that the complex Richards-Plane is a transformed domain of Laplace-Plane which is obtained under a tangent hyperbolic mapping. Network functions generated in terms of Richards's frequency are periodic in actual frequencies with periodicity of pi. Once a low-pass prototype network function is designed in Richards's domain, then its periodic feature makes the corresponding periodic band-pass network function to appear at the certain bands repetitively in the frequency axis. Depend on the application requirements, designer can choose the interested band among these repetitive bands. In this work, a filter is built with microstrip commensurate transmission lines in GSM operation pass-band (0.8 <= f <= 2.4 GHz) . This network can be used in communication applications which are designed to operate in the range of GHz as well as the application in a microstrip patch antenna. In the proposed design, Simplified Real Frequency Technique (SRFT) is employed in the frequency detection network, and the simulation result of microwave office tool (AWR) confirms the theoretical result obtained by MATLAB.Publisher's Versio

2W Wideband Microwave PA Design for 824-2170 MHz Band Using Normalized Gain Function Method

In this work, we present the design of a 2W linear wideband microwave PA (power amplifier) targeted to operate in 824-2170 MHz mobile frequency range covering GSM850, EGSM, DCS, PCS and WCDMA. The design is basically based on the NGF (Normalized Gain Function) method which is very recently introduced into the literature. NGF is defined as the ratio of T and |S-21|(2), i.e. T-NGF= T/|S-21|(2), shape of the gain function of the amplifier to be designed and the shape of the transistor forward gain function, respectively. Synthesis of input/output matching networks (IMN/OMN) of the amplifier requires target gain functions, which are mathematically generated in terms of TNGF. The particular transistor used in the design is FP31QF, a 2W HFET from TriQuint Semiconductor. Theoretical PA performance obtained in Matlab is shown to be in a very high agreement with the simulated performance in MWO (Microwave Office) of AWR Inc