RF Circuit Design

The use of a triple combination of theory, simulation, and lab exercise is most commonly used to promote better student understanding of microwave fundamentals. As part of the RF engineers training education program, an advanced experiments program has been developed in which students can experience successive trial and error procedures including design, circuit fabrication, simulation, and measurement. As a result, it is expected that it be possible for other colleges of technology to use these methods to help students better understand the basis of practical microwave circuit design procedures. In this paper, the design theory and production evaluation process are focused on waveguide inductive and capacitive window.

This paper presents the characterization results of several new passive millimeter wave circuits integrated on very thin ceramic substrate. The work is focused on the design and characterization of a novel rounded Wilkinson power divider, a 90° hybrid coupler, a rat-race coupler, and a novel six-port (multiport) circuit. Measurements show the wideband characteristics, allowing therefore their use for multi-Gb/s V-band wireless communication systems.

The use of a triple combination of theory, simulation, and lab exercise is most commonly used to promote better student understanding of microwave fundamentals. As part of the RF engineers training education program, an advanced experiments program has been developed in which students can experience successive trial and error procedures including design, circuit fabrication, simulation, and measurement. As a result, it is expected that it be possible for other colleges of technology to use these methods to help students better understand the basis of practical microwave circuit design procedures. In this paper, the design theory and production evaluation process are focused on waveguide inductive and capacitive window.

The use of a triple combination of theory, simulation, and lab exercise is most commonly used to promote better student understanding of microwave fundamentals. As part of the RF engineers training education program, an advanced experiments program has been developed in which students can experience successive trial and error procedures including design, circuit fabrication, simulation, and measurement. As a result, it is expected that it be possible for other colleges of technology to use these methods to help students better understand the basis of practical microwave circuit design procedures. In this paper, the design theory and production evaluation process are focused on waveguide inductive and capacitive window.

Advances in electronics technologies have led to a kind of a 'boom' in a very wide range of fields, such as, informatics, bioengineering, communications, electronic gadgets, to name a few. Despites the fact that in the digital domain, designers can take full benefits of IPs and design automation tools to synthesize and design very complex systems, the analog designers' task is still considered as a 'handcraft', cumbersome and very time consuming process. This is mainly due to the lack of support by computeraided design programs, which has led to a so-called 'productivity gap' (difference between what technology can offer and what can be manufactured). Thus, tremendous efforts are being deployed by researchers, R/D engineers, etc. to develop new design methodologies in the analog/RF and mixed-signal domains. Actually, the analog/RF and mixed signal fields rely on three major areas, namely Synthesis, Design and Optimization. These domains form a trilogy in this realm of analog/RF and mixed-signal circuit and system design. Endeavors are being made to develop new synthesis techniques (building novel active circuits, for instance), design methodologies (proposing new circuits) and sizing/optimization techniques (offering more complex functionalities with advanced performances, higher frequency operating ranges, less power consumption, etc.). On this basis, this book collects in sixteen Chapters, recent theories, synthesis techniques and design methodologies, as well as new sizing approaches. It highlights their application to the design of high performance analog/RF and mixedsignal circuits and systems. This book is intended to researchers and R/D engineers, as well. The book encompasses two parts: Methodologies and Techniques. The first part, Methodologies, is composed of seven Chapters, very briefly introduced in the following: Chapter 1, entitled 'Towards Automatic Structural Analysis of Mixed-Signal Circuits', is proposed by M. Eick and H. Graeb. It presents a new method for the automatic structural and functional analysis of analog, digital and mixed-signal circuits. Chapter 2, 'Efficient Synthesis Methods for mm-wave Frequency Passive Components and Amplifiers', authored by B. Liu and G. Gielen, deals with an efficient high-frequency synthesis methods for integrated passive components as well as for the synthesis of mm-wave-frequency linear amplifiers, using the memetic machine

This paper describes the design of the harvester RECTENNA for charging mobile applications. A rectenna (RECtifying anTENNA) is a combination of a receiving antenna and a rectifying circuit which converts RF signal to into direct-current (DC) voltage. The design consists of microstrip patch antenna and Villard voltage doubler circuit which is designed at 900 MHz band.3 stages of Schottky diode voltage doubler circuit are designed and simulated in this paper and matched to the antenna design. CST is used for modelling the antenna using transmission line method, and ADS used for the modelling and simulation of the rectifier. The output voltage of the rectifier is 5.014 V which indicates the suitability for charging mobile applications.

I n this chapter, we will explore the parallel resonant circuit and its characteristics at radio frequencies. We will examine the concept of loaded-Q and how it relates to source and load impedances. We will also see the effects of component losses and how they affect circuit operation. Finally, we will investigate some methods of coupling resonant circuits to increase their selectivity.

In this thesis, a thru-reflect-line (TRL) calibration technique enabling full Sparameter characterisation for membrane circuits has been demonstrated in the WR-03 waveguide band (220 to 325 GHz). The designed membrane TRL kit is packaged in E-plane split blocks. An improvement of beam lead to ground connection was utilized by recessing the block surface. The proposed calibration provides the reference planes right at device under tests, thus reduces an extra de-embedding step. Membrane circuits such as stub filter, thin film resistors, thin film capacitor were characterised by applying the presented method. The simulated and measured results agree well, showing the validity of this approach. Furthermore, the measurement uncertainties such as temperature variation, time drift, system noise, power level fluctuations, connection repeatability and assembly tolerance were systematically investigated. For the connection repeatability study, the amplitude response of transmission coefficient varies within ±0.1 dB while that of reflection coefficient is below-30 dB across the frequency band. In addition, the result of the membrane circuit is not sensitive to circuit mounting tolerance. These analysis prove that this technique is applicable in the WR-03 band. However, it is also very crucial to have a setup with good cables because of the significant impact of the cables on the characterisation result.

This paper describes the design of the harvester RECTENNA for charging mobile applications. A rectenna (RECtifying anTENNA) is a combination of a receiving antenna and a rectifying circuit which converts RF signal to into direct-current (DC) voltage. The design consists of microstrip patch antenna and Villard voltage doubler circuit which is designed at 900 MHz band.3 stages of Schottky diode voltage doubler circuit are designed and simulated in this paper and matched to the antenna design. CST is used for modelling the antenna using transmission line method, and ADS used for the modelling and simulation of the rectifier. The output voltage of the rectifier is 5.014 V which indicates the suitability for charging mobile applications.

The design and simulation of a 2nd harmonic based upconverter is introduced. With the proposed upconverter, it is possible to reach a good noise figure with power and area reduction. The design of the circuit was made with the UMC 0:18 lm Mixed Mode/RF CMOS technology. However, the design methodology can be extended to a different CMOS process. According to the performance exhibited by the purposed mixer, it may be useful in wideband short-range communication technologies, such as certified wireless USB.

This paper presents an efficient analysis of a substrate integrated waveguide (SIW) single-layer hybrid ring coupler (rat-race) for millimeter-wave and microwave applications. The scattered field from each circular cylinder is expanded by cylindrical eigenfunctions with unknown coefficients that have been solved by electric and magnetic tangential boundary on each metallic via. The coupler S-matrix is calculated by using mode matching that uses the cylindrical vector expansion analysis to minimize the computational time and provides more physical insight. To achieve higher bandwidth, the radiuses of the coupler under analysis have been optimized in Matlab code by invasive weed optimization (IWO) method, and the results have been verified by CST package. The return loss and the isolation are less than −15 dB, and −18 dB, respectively. The insertion loss is divided equally-3±0.2 dB, with0±5and180±10degrees in output ports over the operating frequency bandwidth and the agreement of pha...

In this paper, we report two low noise broadband amplifiers based on ABMN's AlGaN/GaN on SiC HEMT technology for X-band applications. Two design topologies, a single-stage (LNA-1) and a two-stage (LNA-2), have been investigated. LNA-1 and the first stage of LNA-2 is based on common source (CS) with inductive source degeneration topology. LNA-1 has a flat gain response of ±1.4 dB gain variation with a gain greater than 8 dB for 9 V drain voltage and 100 mA/mm drain current. Input return loss better than 9.8 dB and output return loss better than 12.8 dB have been achieved. The simulated value of noise figure for this design is less than 1.4 dB. In LNA-2 design, a two-stage topology is implemented to enhance amplifier's gain. The simulated values for LNA-2 show a gain greater than 16.8 dB with ±2.9 dB gain variation. Input and output return loss values are better than 8.8 dB and 10 dB, respectively. The value of noise figure for this design is less than 1.7 dB in the desired frequency range. Both designs, having state-of-the art small dimensions, are suitable for their potential applications for space communications, Radar, satellite communications etc.

This paper describes the design of the harvester RECTENNA for charging mobile applications. A rectenna (RECtifying anTENNA) is a combination of a receiving antenna and a rectifying circuit which converts RF signal to into direct-current (DC) voltage. The design consists of microstrip patch antenna and Villard voltage doubler circuit which is designed at 900 MHz band.3 stages of Schottky diode voltage doubler circuit are designed and simulated in this paper and matched to the antenna design. CST is used for modelling the antenna using transmission line method, and ADS used for the modelling and simulation of the rectifier. The output voltage of the rectifier is 5.014 V which indicates the suitability for charging mobile applications.

High efficiency RF power amplifiers are increasingly needed in modern mobile communication systems to reduce the battery size and power supply consumption. Class-F RF power amplifiers offer improved efficiency over the conventional class-B power amplifiers by properly controlling the harmonic components of the voltage and current signals at the output terminals of the RF device while driving it to operate as an ON/OFF switch. To do this task, a suitable load network is to be synthesized in order to present the proper harmonic impedances at the output of the RF power transistor. In this paper, a new load network for class F power amplifiers has been introduced and derived analytically. The proposed network consists of a parallel short circuited λ/8 stub, parallel open circuited λ/8 stub, and a T-section lumpedelement transformer. The benefits of this topology include simplicity of design, controllable bandwidth, and harmonic tuning and impedance transformation at the same time. To confirm the approach of analysis, a 10 W class-F UHF power amplifier circuit has been designed and simulated using a typical Gallium Nitride high electron mobility RF transistor (GaN HEMT) to operate at 500 MHz with the aid of the Advanced Design System (ADS) computer package. The simulated results have indicated that the circuit gives a dc-to-RF efficiency of more than 84 % and a power gain of 11 dB at 500 MHz with an operating bandwidth from 440 to 540 MHz.

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.

The need for new technologies to handle peak high speed data rates for the aforementioned communication benefits has unquestionably grown exponentially over the last few years. In this paper, a receiver RF front end mixer design operating for 5G NR application. The BJT transistor with part number BFP405F is selected for the down conversion mixer design. Transistor is biased and check for the stability at the given frequency. Matching circuit is designed for the transistor to obtain the better conversion gain and return loss. The input RF and LO frequencies are 3.5 GHz and 3.3 GHz, respectively, with input power -10 dbm at LO path. The output frequency obtained at the IF is 200 MHz. The designed active down conversion mixer is simulated in ADS. The desired mixer has good linearity, a modest conversion gain, and good return loss. Conversion gain for the designed down conversion mixer is +5.03 dB.

This paper presents the design of a wideband monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) using GaAs pseudomorphic high electron mobility transistor (pHEMT) technology. The flat gain of 30 dB ± 0.5 dB is achieved using a three-stage amplifier topology over 4-12 GHz. The minimum noise figure of 1.0 dB is achieved in a packaging chassis within the frequency band. In order to achieve such a low noise over a wideband, several bandwidth enhancement techniques are applied in the design. An inductive feedback at the source of the first stage results in a very wideband input matching (|S11| <-12 dB) over 3-15 GHz. The gold wire bonds at the input and output of the chip are separately analyzed and modeled into matching networks to ensure wideband low noise behavior of the chip after packaging. This GaAs pHEMT LNA is suitable for radio astronomy receivers such as the Atacama Large Millimeter Array Band 3 IF warm amplifiers.

High efficiency RF power amplifiers are increasingly needed in modern mobile communication systems to reduce the battery size and power supply consumption. Class-F RF power amplifiers offer improved efficiency over the conventional class-B power amplifiers by properly controlling the harmonic components of the voltage and current signals at the output terminals of the RF device while driving it to operate as an ON/OFF switch. To do this task, a suitable load network is to be synthesized in order to present the proper harmonic impedances at the output of the RF power transistor. In this paper, a new load network for class F power amplifiers has been introduced and derived analytically. The proposed network consists of a parallel short circuited λ/8 stub, parallel open circuited λ/8 stub, and a T-section lumpedelement transformer. The benefits of this topology include simplicity of design, controllable bandwidth, and harmonic tuning and impedance transformation at the same time. To co...

In this paper a new design of a broadband microwave&lt;br&gt; power limiter is presented and validated into simulation by using&lt;br&gt; ADS software (Advanced Design System) from Agilent technologies.&lt;br&gt; The final circuit is built on microstrip lines by using identical Zero&lt;br&gt; Bias Schottky diodes. The power limiter is designed by Associating 3&lt;br&gt; stages Schottky diodes. The obtained simulation results permit to&lt;br&gt; validate this circuit with a threshold input power level of 0 dBm until&lt;br&gt; a maximum input power of 30 dBm.

A method of optimizing components and transistors sizing for CMOS Cross-Coupled LC voltage controlled oscillators is presented in this paper. The design constrains of power consumption, phase noise, and the Figure of Merit (FoM) of LC_VCOs are applied on Multi-Objective AI techniques, simultaneously. The design parameters of LC_VCOs are obtained from the two strong algorithms, the Multi-Objective Inclined Planes system Optimization (MOIPO) and the Multi-Objective Particle Swarm Optimization (MOPSO). It was  implemented in MATLAB, to the Pareto Optimal Front (POF) solutions, which have an amazingly trade-off between three objective functions. The LC_VCO circuits were simulated using this method in a 0.18μm-CMOS process by HSPICE RF environment. The results show that the size of components of the PMOS-only and NMOS-only integrated LC_VCOs and the optimal trade-off curve between minimum power and minimum phase noise.

In this paper, we present the design of ultra wideband (UWB) planar Five-Port Reflectometer using the elliptic coupler which has the advantage to offer a wide bandwidth compared to the hybrid one. The elliptic coupler and the five-port circuit were designed and simulated in the 1.5 to 3.5 GHz band using ADS software of Agilent. An analytical calculus and simulation results of a five-port circuit using elliptic coupler demonstrate limitations of this structure.

A three-port power divider consisting of a directional coupler, a Wilkinson power divider, and two transmission lines connected to them is proposed. Theoretical analysis reveals that highly unequal power division can be achieved by a feedback mechanism of two transmission lines along with the coupling coefficient of the directional coupler and the power division ratio of the Wilkinson power divider. The three-port power divider inherits the performance characteristics of high isolation, low reflection coefficients at all ports, and the minimum number of components. The proposed power divider is designed at 5.8 GHz and fabricated and evaluated through measurements. It demonstrates that electromagnetic simulation results are in good agreement with theoretical prediction and measurement results. The three-port power divider is compact in the planar form, so it can be easily integrated into radio frequency front ends.

In this paper, a 10 W ultra-broadband GaN power amplifier (PA) is designed, fabricated, and tested. The suggested design technique provides a more accurate starting point for matching network synthesis and better prediction of achievable circuit performance. A negative-image model was used to fit the extracted optimum impedances based on source-/load-pull technique and multi-section impedance matching networks were designed. The implemented amplifier presents an excellent broadband performance, resulting in a gain of 8.5 ± 0.5 dB, saturated output power of ≥10 W, and power added efficiency (PAE) of ≥23% over the whole bandwidth. The linearity performance has also been characterized. An output third-order intercept point (OIP3) of ≥45 dBm was extracted based on a two-tone measurement technique in the operating bandwidth with different frequency spacing values. The memory effect based on AM/AM and AM/PM conversions was also characterized using a modulated WiMAX signal of 10 MHz bandwi...

Single pole double throw (SPDT) switch is commonly used in radio frequency (RF) transceiver system for time division duplex (TDD) operation of digital communication system. The proper selection of SPDT switch topology or configuration is very important in order to meet wireless digital communication performance. Therefore, this paper reports on the analysis of insertion loss, return loss and isolation for three different configurations (Type A, Type B and Type C) of series-shunt SPDT switch at 2.4 GHz. In early stage of product development, the analyses have been performed in simulation software. As a result, Type C has shown better insertion loss and isolation in transmit and receive mode compared with other configurations.

The paper concentrates on summarizing significant worldwide developments in the Low Noise Amplifier domain for the Square Kilometre Array telescope. Several technologies, design topologies and noise measurement techniques of LNAs for SKA have been proposed and analysed since the commencement of the project in 2000. Transistor technologies including GaAs mHEMT, GaAs pHEMT, SiGe HBT, CMOS, InP pHEMT have been extensively studied and characterised at multiple institutes around the world. The proposed site of SKA is either Western Australia or South Africa. Both sites experience a very significant physical temperature variation even over a 24 hour period. Hence temperature dependant studies on the DC, small signal and noise characteristics of different transistors have been carried out. Cryogenic characterisation down to 15K physical temperature of certain types of transistor technologies has also been performed. Both hybrid and MMIC LNAs based on the above technologies have been designed and measured. Depending on the antenna topology and impedance, both single ended and differential LNAs with various input impedances have been explored. Performance of LNA integrated with the antenna has been simulated and the effect of the variation of antenna impedance on the overall performance of the before mentioned components have been studied. Design, development and comprehensive analysis of measured data of both variations of LNA and their pros and cons have been portrayed in this paper. Due to system architecture requirements, differential input-single ended output LNA configuration has been designed and measured. In this paper their advantages, disadvantages and their sources will be identified. Some interesting theories and techniques of differential noise measurements have been proposed during SKA project and will also be explained as part of this paper.

The design trade-offs of a transmitter (TX) for the Medical Device Radiocommunications Service (MedRadio), which encompasses low power consumption in a bandwidth from the 401MHz to the 406MHz, small form factor and robustness, are discussed in this work. The aim is to determine the key factors for linearity and efficiency in a direct-up TX architecture suitable for MedRadio. A solution based on the use of a predriver amplifier preceding the power amplification stage with output power modulation is sketched. Experimental results of the predriver prototype in a double poly, three metal layers, 0.5µm CMOS technology show the effectiveness of the proposed circuit for high efficiency frequency translation.

dBc/Hz,.respectively..The.proposed.approach,.implemented.in.AIDA-C,.guarantees.accuracy.by.using. commercial.circuit.simulators.(HSPICE®.and.ELDO®).to.evaluate.the.performance.of.the.tentative. circuit.solutions,.where.the.number.of.time-consuming.circuit.simulations.is.efficiently.pruned.by.the. optimization. kernel.. Three. multi-objective. optimization. algorithms,. the. NSGA-II,. the. MOPSO,. and. the.MOSA,.are.experimented.with.in.the.synthesis.of.the.quoted.oscillators.and.compared.in.terms.of. performance.using.statistical.results.obtained.from.multiple.synthesis.runs.for.each.one.of.the.oscillators.. The.performance.of.the.optimized.oscillators.is.then.compared.to.other.state-of-the-art.results,.showing. the.benefits.of.the.presented.multi-objective.design.approach. Design.Guidelines.for.Improving.the.Power-Added-Efficiency.of.CMOS.RF.Multipath-Polyphase. Power.Amplifiers.

All Rights Reserved have achieved this goal in my life. To my sisters, Seo-Young and Hye-Sook, and my brother, Hyung-Geun, I give thanks for their love and encouragement. Finally, I would like to thank my wife, Hyekyung, for her unlimited patience and encouragement, which has been the greatest source of energy for me to keep going forward during the entire of this work. She has gone through many challenges along with me including giving birth to our son, Heesoo

This paper presents the characterization results of several new passive millimeter wave circuits integrated on very thin ceramic substrate. The work is focused on the design and characterization of a novel rounded Wilkinson power divider, a 90 ∘ hybrid coupler, a rat-race coupler, and a novel six-port (multiport) circuit. Measurements show the wideband characteristics, allowing therefore their use for multi-Gb/s V-band wireless communication systems.

The wireless communication industry grows faster each day. In terms of RF power amplifier (RFPA), the requirements on efficiency, linearity, bandwidth, output power and cost are getting more stringent. RFPA is considered as the most important component because of consuming large power in a base station. In this paper, a systematic approach is used to design a high flat gain class-F RFPA over an octave bandwidth. The simulation of a 1.5GHz class-F power amplifier mode demonstrates a high drain efficiency while accomplishing a high flat gain over a wide bandwidth. To identify the optimum impedance for the output matching and input matching network, the load-pull and source-pull are performed. The simulation results show that the RFPA can deliver a drain efficiency of 68.37 % at the output power of 40.79 dBm with power added efficiency of 66.94 %. The designed PA achieved a high gain between 13 dB to 17 dB from 0.5 GHz to 2.0 GHz of a frequency band. The matching circuits are realized ...

Linearity plays an important role in the design and implementation of radio frequency power amplifier. Although negative resistance circuits are non-linear circuits, they are associated with distortion, which may either be amplitude-to-amplitude distortion or amplitude-to-phase distortion. In this paper, a unique way of realizing a negative resistance amplifier is proposed using a single Metal-Semiconductor Field-Effect Transistor (MESFET). Intermodulation Distortion Test (IMD) is performed to evaluate the characteristic response of the negative resistance circuit amplifier to different bias voltages using the Harmonic Balance (HB) of the Advanced Designed Software (ADS 2016). The results obtained showed that the proposed negative resistance amplifier exhibits a stable edge gain than a conventional distributed amplifier.

A direct-coupled, lumped broadband amplifier utilizing InP/InGaAs single heterojunction bipolar transistors (SHBT) is presented. The achieved-3 dB-bandwidth is 50 GHz with a dcgain of 9.8 dB and a gain-peaking of only 1.2 dB. To our best knowledge, this is the largest bandwidth reported for InP/InGaAs HBT amplifiers with such a flat gain curve.

This paper reports the design and measurement of a dual band monolithic AGC amplifier to be used in transmit/receive modules for Telemetry, Tracking and Control (TTC) of satellite systems. The amplifier is also included in a multifunction Monolithic Microwave Integrated Circuit, MMIC, containing frequency converters. The block diagram of this chip is shown in figure 1. The goal of the work is to reduce the number, size, and consequently, the cost of the circuitry actually in use, whilst maintaining performance, through the use of mature GaAs PHEMT technology. Issues such as circuit topologies, dc power consumption, circuit area minimization and optimization are all important factors that are addressed during the design.

This paper reports the design and measurement of a dual band monolithic AGC amplifier to be used in transmit/receive modules for Telemetry, Tracking and Control (TTC) of satellite systems. The amplifier is also included in a multifunction Monolithic Microwave ...

Radio Frequency Power amplifier is one of the essential module in the transmission chain of wireless Base stations. There is always a trade-off exists between power efficiency and linearity of the power amplifier. The design of power amplifier using LDMOS based active devices will give cost-effective solution. This work presents the design of a Class A power amplifier for unlicensed ISM band wireless Base station requirements. The design is carried out using Si-LDMOS (Silicon- Laterally Diffused Metal Oxide Semiconductor) technology and is built on Epoxy-FR4 (Flame Retardant, woven glass reinforced epoxy resin) board with a dielectric constant of 4.6 and substrate thickness of 1.6 mm. The amplifier design uses Free scale Si-LDMOS MW6S004NT1 transistor model in Agilent’s Advanced Design System (ADS 2011). The simulation was carried out to analyze the behaviour of power amplifier in the 2.4GHz ISM band. The simulated results has shown an acceptable behaviour with a gain of 16.558 dB, ...

The design of optimal analog and mixed signal (AMS) very large scale integrated circuits (VLSI) with lesser design cycle time is a challenging task for the integrated circuit (IC) designers. Voltage Controlled Oscillator (VCO) is a radio frequency integrated circuit (RFIC) having wide range of applications. This paper presents a new approach to design a ring oscillator (RO) with optimum performance with only one design cycle. The optimal figure of merit performance for a RO with a constraint of achieving a desired centre frequency is observed using a new technique which combines multi-objective optimization with differential evolution (CMODE). The RO is designed by considering the design parameters extracted from constrained CMODE in Cadence Virtuoso analog design environment (ADE) using gpdk090 library. The simulation results are compared with the CMODE predicted indices and are observed to be in good agreement with it. In this work RO circuits with 9 stages of inverters are considered to be designed for 2 GHz centre frequency with the limitations imposed by gpdk090 library. Results of exhaustive simulation and experimental studies for these ROs are presented here to verify the reduced design cycle time and superior performance offered by the proposed design methodology.

The design of optimal analog and mixed signal (AMS) very large scale integrated circuits (VLSI) with lesser design cycle time is a challenging task for the integrated circuit (IC) designers. Voltage Controlled Oscillator (VCO) is a radio frequency integrated circuit (RFIC) having wide range of applications. This paper presents a new approach to design a ring oscillator (RO) with optimum performance with only one design cycle. The optimal figure of merit performance for a RO with a constraint of achieving a desired centre frequency is observed using a new technique which combines multi-objective optimization with differential evolution (CMODE). The RO is designed by considering the design parameters extracted from constrained CMODE in Cadence Virtuoso analog design environment (ADE) using gpdk090 library. The simulation results are compared with the CMODE predicted indices and are observed to be in good agreement with it. In this work RO circuits with 9 stages of inverters are consid...

Linearity plays an important role in the design and implementation of radio frequency power amplifier. Although negative resistance circuits are non-linear circuits, they are associated with distortion, which may either be amplitude-to-amplitude distortion or amplitude-to-phase distortion. In this paper, a unique way of realizing a negative resistance amplifier is proposed using a single Metal-Semiconductor Field-Effect Transistor (MESFET). Intermodulation Distortion Test (IMD) is performed to evaluate the characteristic response of the negative resistance circuit amplifier to different bias voltages using the Harmonic Balance (HB) of the Advanced Designed Software (ADS 2016). The results obtained showed that the proposed negative resistance amplifier exhibits a stable edge gain than a conventional distributed amplifier.

Linearity plays an important role in the design and implementation of radio frequency power amplifier. Although negative resistance circuits are non-linear circuits, they are associated with distortion, which may either be amplitude-to-amplitude distortion or amplitude-to-phase distortion. In this paper, a unique way of realizing a negative resistance amplifier is proposed using a single Metal-Semiconductor Field-Effect Transistor (MESFET). Intermodulation Distortion Test (IMD) is performed to evaluate the characteristic response of the negative resistance circuit amplifier to different bias voltages using the Harmonic Balance (HB) of the Advanced Designed Software (ADS 2016). The results obtained showed that the proposed negative resistance amplifier exhibits a stable edge gain than a conventional distributed amplifier.

In this paper, we present the design, fabrication, and electrical characterization of a low-power microwave source for interrogation of cesium atomic hyperfine transition frequency using the coherent population trapping (CPT) technique. The 4.6-GHz frequency generation and signal buffering is performed by a single-chip frequency synthesizer ASIC with a frequency tuning resolution of 1 × 10 −13 and a programmable RF output power from −10 to 0 dBm. The circuit was used to modulate the current of a vertical-cavity surface-emitting laser through a dedicated impedance matching network and low thermal conductivity transmission line. Strong modulation sidebands with >60% of carrier amplitude were obtained with an ASIC power consumption of 12 mW. The system was used as optical source for atomic interrogation in an experimental cesium CPT clock. The measured clock stability of 5 × 10 −11 at τ = 1 s, going down to 4.5 × 10 −12 at τ = 200 s, is limited by the signal-to-noise ratio of the detected CPT signal.

High frequency class F and inverse class F power amplifiers obtain high efficiency of dc to ac power conversion, by reducing the overlap of voltage and current waveforms at the output of the active device, to ensure that the power dissipated in the resistance R on of the active device is minimised. In this paper the active device is modelled as a switch in series with resistance R on 0 to 5Ω. For ideal switch voltage / current waveforms and equal dc input power for both amplifiers the efficiency of power conversion is compared. To confirm the predicted results ideal lossless load harmonic networks using lumped elements were designed to meet all frequency conditions of the two amplifiers. These networks were done used in Advanced Design System (ADS) software for R on =0, 2 and 4 Ω. The predicted efficiency for 2Ω and 4 Ω were 80% and 60% and the obtained simulation efficiency were 83.2% and 65.5% for class F amplifier. For the inverse class F amplifier the predicted efficiency was 87.3% and 74.5% and for the simulation results it was 87.26% and 74.4%. Above predicted and simulated results show that the resistance R on has less effect on the efficiency of inverse class F than for class F amplifier. As lumped elements can not be used at high frequencies they were replaced initially with lossless transmission lines and then by microstrip lines to also investigate also how copper and dielectric losses affect the efficiency of power conversion.

In this paper, we present the design of ultra wideband (UWB) planar Five-Port Reflectometer using the elliptic coupler which has the advantage to offer a wide bandwidth compared to the hybrid one. The elliptic coupler and the five-port circuit were designed ...

We propose a compact wideband multi-way power divider/combiner with planar structure for applications to RF power amplifiers (PAs). Uniform transmission lines in the conventional divider are replaced with non-uniform transmission lines (NTLs), which are governed by a truncated Fourier series. An optimization-driven framework is employed in even-mode analysis to obtain the coefficients of the NTLs considering predefined operating bands, whereas three isolation resistors are optimized in the odd-mode analysis to achieve optimal isolation and output port matching over the design bandwidth. For verification purposes, a 4-10 GHz 3-way divider is simulated, and measured. Simulations and measurements are in close proximity and show input/output ports matching of better than-10 dB and transmission of-4.9 ±1 dB across the design bandwidth. Index Terms-multi-way power divider, non-uniform transmission lines (NTLs), power amplifiers (PAs), power combiner, wideband Wilkinson power divider (WPD).

An ultra-wideband (UWB) modified 3-way Bagley polygon power divider (BPD) that operates over a frequency range of 2–16 GHz is presented. To achieve the UWB operation, the conventional quarter-wave transformers in the BPD are substituted by two tapered line transformers. For verification purposes, the proposed divider is simulated, fabricated, and measured. The agreement between the full-wave simulation results and the measurement ones validates the design procedure.

Based on the portable systems application, it is necessary to design blocks with high efficiency to increase battery lifetime. Power amplifier is the highest power consumption block in transmitter. The proposed circuit was simulated using ADS Agilent based on 0.18 μm TSMC RF CMOS technology and supply voltage of 3.3V on transistor level. The proposed power amplifier was designed by Class F type at 1800 MHz with 60% efficiency and output powers of 30 dBm.

This paper investigates an evolutionary-based designing system for automated sizing of analog integrated circuits (ICs). Two evolutionary algorithms, genetic algorithm and PSO (Parswal particle swarm optimization) algorithm, are proposed to design analog ICs with practical user-defined specifications. On the basis of the combination of HSPICE and MATLAB, the system links circuit performances, evaluated through specific electrical simulation, to the optimization system in the MATLAB environment, for the selected topology. The system has been tested by typical and hard-to-design cases, such as complex analog blocks with stringent design requirements. The results show that the design specifications are closely met. Comparisons with available methods like genetic algorithms show that the proposed algorithm offers important advantages in terms of optimization quality and robustness. Moreover, the algorithm is shown to be efficient.