Passives and Actives Microwaves Circuits Design

This paper presents the design, simulation, and implementation of band pass filters in rectangular waveguides with radius, having 0.1dB pass band ripple and 6.3% ripple at the center frequency of 14.2 GHz. A Mician microwave wizard software based on the Mode Matching Method (MMM) was used to simulate the structure of the filter. Simulation and measured results show the validity of the waveguide band pass filter design method.

The goal of this laboratory work is to get acquainted with receiver system design. Moreover, we should obtain and observe behaviors of phase noise and two-tone test. Understanding the
concept of intermodulation distortion and basic analysis of its effect on overall performance is a required task.
There are three experiments overall. In the first part, we obtain a frequency spectrum, containing of two signals, 2.33 and 2.4 GHz. There are several nth order intermodulation products can be seen. In the second part, we perform phase noise simulation and observe noise decay in log frequency scale. Finally, n-tone test is performed. At the input, three input frequencies are defined: 2.33, 2.399, 2.401 GHz. It results in frequency difference between
output tones.

In this lab, a study of microstrip antennas has been carried. Furthermore, the theoretical meaning of scattering parameters has been provided. With the help of circuit simulation software, microstrip antenna has been designed and its behavior characteristics were obtained. In particular, scattering parameters has been plotted and analyzed.

A compact, circular UWB fractal antenna with triple reconfigurable notch rejection bands is proposed. It rejects the crowded frequency bands WiMAX, WLAN and X band interferences produced in UWB communication systems. The proposed fractal structure consists of a basic circular patch with circular fractal iterations. By employing this new structure of fractals, the overall size of antenna is reduced 53% to 21x25 mm, in comparison with traditional circular monopole antenna. The implemented antenna operates at 3.1-10 GHz. Re-configurability is realized by designing slots and split ring resonators in desired frequencies with the attached PIN diodes. WLAN band rejection was realized by creating a pair of optimized L-shaped slots in the ground plane. By etching a split ring resonator and a U-shaped slot, X and WiMAX bands were also rejected. Furthermore, by attaching diodes to aforementioned slots and designating the diodes on/off, different bands can be included or rejected. In time domain, the antenna properties are evaluated by a figure of merit called fidelity factor. Finally, the antenna properties are measured in anechoic chamber and the results agrees with simulation findings.

International Journal of Microwave Engineering (JMICRO) is a peer-reviewed, open access journal which invites high quality manuscripts that focuses on Engineering and theory associated with microwave / millimeter-wave technology, guided wave structures, electromagnetic theory and implementation. Authors are invited to submit original research works that stimulate the development of latest technology in industry and academia. Good quality review papers and short communications are also acceptable. Research areas suitable for publication include, but are not limited to the following fields:  2D/3D printed RF and microwave components  Antenna modelling and measurements  Channel modelling and propagation  Cognitive and adaptive radio  Digital beam forming  EMI/EMC  Ferroelectric, ferrite and acoustic wave components  Hybrid and monolithic active components (amplifiers, mixers, oscillators, etc)  Methods of maintaining signal integrity  Micro-machined transmission lines and waveguides  Microwave and millimetre wave systems  Microwave device modelling  Microwave photonics  MIMO components  Novel waveguides and new phenomenon in waveguides  Optical/Fiber techniques  Passive components (filters, couplers, transitions, etc)  Phased array  Radar, SAR and microwave engineering  Receiver components  RF MEMs and micro-systems  RF Nanotechnology: Carbon, semiconductors and other novel material based nanotechnology, nano-devices, meta-materials and nano-scale RF components  RFID technologies: HF/UHF/RF passive and active RFID tags and readers, printed RFID's  Signal generation and modulation circuits  Smart antennas  THz components and technologies  Transmitter components  Wideband and multiband antennas  Wireless and cellular architectures, circuits and component

The realization of a software-defined radio has been a particular objective of the military industry and academia in Turkey. Broadband frequency-tunable PAs and matching networks [28], [29] (see Figure 2) were designed at METU–Northern Cyprus Campus’s RF and Telecommunication Laboratory (established by Dr. Tayfun Nesimoglu [30]) using RFT [8]–[18].

This paper presents a direct synthesis approach for UWB BPFs. The modified Chebyshev filtering function is used to characterize the frequency response over the whole frequency range of the BPF. As for the filter's circuit, open circuited MMR capacitively coupled with I/O ports is used, and two shunt short-circuited stubs are placed at the two ends of the connecting line to sharpen the rejecting skirt of the passband. The equivalent circuit's transfer function is derived. By equating the filtering function to the transfer function of the circuit, the design parameters are obtained. The uniform connecting line is then replaced by nonuniform line to suppress spurious harmonics and achieve very wide stopband. In order to avoid critical precision requirement in the fabrication of the filter, we design the filter using suspended stripline (SSL) technology to replace the parallel-coupled microstrip lines (PCML) with very small coupling gaps. Finally, a filter prototype is designed and fabricated to experimentally validate the presented method. Experimental results show good agreement with EM-simulated and theoretical ones.

Los radares tienen múltiples aplicaciones y su uso es vital en el sector aeroespacial; de ahí la importancia de formar especialistas en esta área y, por lo tanto, la de contar con herramientas pedagógicas adecuadas. Se plantea la necesidad de implementar algún equipamiento a nivel educativo para potenciar el proceso de enseñanza-aprendizaje de aquellas personas que se encuentran transitando la etapa universitaria de ingeniería. Más precisamente, se busca desarrollar un sistema integral para el aprendizaje de los estudiantes de Ingeniería en Electrónica que cursan asignaturas vinculadas al área de microondas y radares en la Facultad de Ingeniería de la Universidad de Mendoza. El presente trabajo expone un caso de resolución práctica que permite satisfacer esta necesidad, al adaptar un equipo existente.

Is presented in this paper a new Ultra Wide Band (UWB) transmitter circuit design to a small Vivaldi antenna for remote acquisition of vital signals through telemetry by microwaves. Recently, interest in research on generation and transmission of UWB pulses has increased, especially for application in the remote sensing of heartbeat signals (e.g. of an operator of a drilling rig in an industrial oil plant off-shore) and the measurement of respiration rate (e.g. of the crew of an aircraft. This technique consists of a transmitter (this work) and a receiver for perform telemetry for estimating the vital signs though detection of the movements of heart and lung. The system consists of a second Gaussian Pulse Generator (PG) circuit installed on a Vivaldi planar antenna. The circuit was designed using 180nm Mosis-IBM process and the planar antenna array was designed with copper and RO3206 substrate. Spice simulations show the generation of pulses with 156,6mVpp amplitudes and 200ps width, and a central frequency of 6GHz. The dynamic energy consumption is around 0.7pJ and average power consumption of 3mW per pulse using 2V power supply at pulse repetition rate (PRR) of 100MHz. The electromagnetic simulations show the Main Lobe with an average magnitude of 5.1dBi at 6GHz, and a beam angular width of the 138º x 62º.

This paper presents a new circuit of the miniature microwave radiometer for wearable devices, which can be used to monitor the core body temperature (CBT) of internal human tissues continuously 24/7. The measurement results of the proposed device, as opposed to the known miniature wearable radiometers, remain unchanged when the impedance of the examined area varies. We have derived an analytical expression for radiometer measurement error based on parameters of device components. This formula allows accuracies to be estimated and optimal parameters of the circuit to be selected to minimize measurement error at a design stage. It is shown that measurement error is independent of the antenna reflection coefficient and the temperature of the radiometer front-end. A prototype of the single-channel miniature radiometer has 32 × 25 × 14 mm3 dimensions and USB interface communication with PC. A 28 hour run of the device has shown that it is highly stable, and a maximum drift in temperature is 0.15̊ C. Operating frequency range was 3400−4100 MHz, supply voltage −5 V; power supply of the radiometer in measurement mode is 210 mA; time constant of the radiometer without being averaged is 0.6 s, at the same time, standard deviation  = 0.17 ̊C, with further averaging during 4 s  = 0.052 ̊C, with averaging during 30 s  = 0.017 ̊C; when there were input reflections R2 = 0.25, an error in measuring brightness temperature shifted by 0.2 ̊C; with 10 ̊C variations in ambient temperature the shift was 0.15̊ C.

This article reports the development and characterization
of a robust RF transceiver system for wireless monitoring of the pressure
variation in a gas pipeline installed in an industry. Proposed system
consists of a monolithic silicon pressure sensor for converting
applied pressure information to a DC voltage output, a varactor-based
voltage controlled oscillator (VCO) for converting DC voltages to RF
signal, a power amplifier for amplifying the transmitting RF signal, and
two wideband microstip fed filtering antennas used in transmitter and
receiver modules. Transmitting antenna is used for radiating the selected
RF signal (conditioned pressure information) while reflecting the undesired
harmonics. Filtering antenna (Filtenna) at the receiver side is
used to detect the desired RF signal while filtering out the undesired
signal. Operating frequency band of proposed wireless pressure monitoring
system is 2.2565–2.5804 GHz covering lower ISM band (2.4–
2.5 GHz). As a proof of concept, experiment has been performed for
monitoring of a pressure variation in the range 0–50 kPa and for a distance
of 2 m between transmitting and receiving antennas. The measured
pressure sensitivity of the proposed gas pressure monitoring system is
6.4786 MHz/kPa with a good linearity response. Calibration curve and
curve fitting equations are provided for evaluating the pressure variation
in a gas pipeline by detecting the received RF signal at the receiver
end. Proposed system can be used for wirelessly monitoring the pressure
of a gas pipeline installed in an industry.

The article is devoted to the development of a printed ultra-wideband miniature antenna that can be used for microwave radiometry. An antenna design with a ring-shaped radiator has been proposed, which provides reception of microwave radiation from biological tissues in the 1800–4600 MHz range. The results of mathematical modeling of the antenna electromagnetic field in biological tissues using the finite difference time domain (FDTD) method are presented. Optimization of the antenna design has been carried out to ensure acceptable matching parameters and optimal antenna functionality. The developed antenna has a height of 6 mm and a calculated mass of 5 g; it is planned to manufacture a dielectric substrate based on PDMS polymer with the addition of barium titanate. The issues of calculating the antenna parameters (measurement depth, resolution and distribution of radiation power over the volume of biological tissue, sensitivity, etc.) are considered. The research results and desig...

This paper presents the design of high-speed full adder circuits using a new CMOS mixed mode logic family. The objective of this work is to present a new full adder design circuits combined with current mode circuit in one unit to implement a full adder cell. This paper also discusses a high-speed hybrid majority function based 1-bit full adder that uses MOS capacitors (MOSCAP) in its structure with conventional static and dynamic CMOS logic circuit. The static Majority function (bridge) design style enjoys a high degree of regularity and symmetric higher density than the conventional CMOS design style as well as lower power consumption by using bridge transistors. This technique helps in reducing power consumption, propagation delay, and area of digital circuits while maintaining low complexity of mixed-mode logic designs. Dynamic CMOS circuits enjoy area, delay and testability advantages over static CMOS circuits. Simulation results illustrate the superiority of the new designed adder circuits against the reported conventional CMOS, dynamic and majority function adder circuits, in terms of power, delay, power delay product (PDP) and energy delay product (EDP). The design is implemented on UMC 0.18µm process models in Cadence Virtuoso Schematic Composer at 1.8 V single ended supply voltage and simulations are carried out on Spectre S.. KEYWORDS Full adder, Majority-Not gate, Dynamic circuits, MOSCAP, Power-delay product (PDP), Very Large Scale Integrated (VLSI) Circuits, Current mode logic, Hybrid XOR-XNOR circuit, Bridge full adder.

A small cell’s smaller range compared to the macrocell allows the former to increase network capacity through frequency reuse. On the flip side, more small cells are needed to provide the same coverage as one macrocell. Hence, it is necessary to make small cell equipment significantly cheaper than its macrocell counterpart. One way to save cost is by using one broadband radio module instead of multiple narrowband radio modules to support different air interfaces. A low-noise amplifier (LNA) is an essential component in the receive portion of the radio module. Conventionally, the LNA is impedance matched for low noise at one frequency, but the small cell’s single radio module has to cover multiple frequencies. Resistive shunt feedback can widen an LNA’s bandwidth but results in tradeoffs of noise figure (NF), gain, and output-power performance. Fortunately, small cell LNAs have less demanding noise requirements than macrocells’ because they cover smaller areas. The output-power requirement is also lower because the small cell’s low height (~10 m) is less susceptible to interference. To compensate for the increased noise due to feedback, the LNA can utilize a low-noise semiconductor process, such as a GaAs enhancement-mode pseudomorphic high-electron-mobility-transistor process (E-pHEMT). Although discrete ePHEMTs can be used to realize low-noise feedback amplifiers, monolithic microwave integrated circuit (MMIC) technology can advantageously reduce component count by integrating amplifier, feedback, and biasing circuits. As time-division-duplex (TDD) uses a common frequency for transmit and receive, the LNA must be powered down during transmission to prevent overdrive. Hence, integrating the power-down function is another way to further reduce component count. This paper presents the design and performance validation of the new MMIC.

The MMIC is packaged in Quad Flat No-lead 2x2 (QFN) and requires eight external components only. The prototype achieved sub 0.8 dB NF over 0.3–1.6 GHz. The experimental input return loss (IRL) is better than –15 dB and output return loss (ORL) is better than –14 dB. The output third order intercept point (OIP3) exceeds 30 dBm over the aforementioned frequency range. The power output at 1 dB gain compression (P1dB) exceeds 20.4 dBm. The power-down function's turn-on time (tON) and turn-off time (tOFF) are 1.5 uS and 0.04 uS, respectively. In conclusion, the small cell LNA requirements for wide bandwidth, low cost and minimum components can be achieved through MMIC integration of LNA, feedback, biasing and power-down functions.
Keywords: Monolithic microwave integrated circuit low noise amplifier, MMIC LNA, small cell, power down switch for time domain duplex

Higher harmonics normally accompany the performance of bandpass ¯lers; and
the miniaturized microstrip dual mode bandpass ¯lters are not an exception. The use of the
conventional open stub resonator to reduce such harmonics is not a practical solution since it
has a length of a quarter the guided wavelength at the harmonic frequency. This will make the
miniaturized ¯lter larger. In this paper, the use of a fractal based open stub, with high space ¯lling
property, has been investigated as a more practical solution of the 2nd harmonic reduction of the
miniaturized dual mode bandpass ¯lters. The proposed stub has the Peano fractal shape geometry
which is characterized by its high space-¯lling property. The Peano based stub has been applied
to many miniaturized ¯lter reported in the literature. Modeling and performance evaluation
of the presented ¯lters have been carried out using a full-wave electromagnetic EM simulator,
from Sonnet Software Inc. Simulation results show that the introduction of the proposed stub
maintains the physical size of the ¯lter under test and improves the ¯lter performance by reducing
the harmonics to satisfactory levels. This might presents a solution for second harmonic reduction
of a wide variety of miniaturized dual mode bandpass ¯lters with di®erent miniaturization levels.

A novel fractal dual-mode microstrip bandpass filter design has been introduced in an attempt to produce filters with highly miniaturized size for modern wireless applications. The filter structure has been generated based on the 3rd iteration Minkowski-like pre-fractal geometry, using the conventional dual-mode square ring resonator as the initiator in the fractal generation process. The space-filling property, self-similarity and the diagonal symmetry of the structures corresponding to the successive iteration levels of this fractal geometry have found to produce reduced size filter structures with accepted performance. The bandpass filter structure produced by the 3rd iteration of this fractal geometry can be considered as a novel design with adequate performance. This design structure possesses a size reduction of about 72% compared with the conventional dualmode square ring resonator operating at the same frequency and using the same substrate material. In addition, the new des...

This paper presents a novel compact Wilkinson Power Divider (WPD) that improves harmonics suppression. The proposed WPD consists of a shunt open stub between two series similar inductors, and a microstrip line between an isolation resistor and each output port. This configuration acts as a low-pass filter with two transmission zeros. In addition, it facilitates manufacturability by using lower transmission line impedance values than conventional structures. Through even and odd mode analysis, the general design equations have been derived in closed form. A 2 GHz microstrip WPD is designed, fabricated and measured based on the proposed technique. A great agreement has been obtained between the measured performance of fabricated WPD circuit and the simulation results. The measured results show that the second and third harmonic levels are about −46 dB and −36 dB, respectively. The proposed design has about 40% reduction in size better than conventional WPD. It achieves competing results compared to other published work.

The article is devoted to the development of a printed ultra-wideband miniature antenna that can be used for microwave radiometry. An antenna design with a ring-shaped radiator has been proposed, which provides reception of microwave radiation
from biological tissues in the 1800–4600 MHz range. The results of mathematical modeling of the antenna electromagnetic field in biological tissues using the finite difference time domain (FDTD) method are presented. Optimization of the antenna design has been carried out to ensure acceptable matching parameters and optimal antenna functionality. The developed antenna has a height of 6 mm and a calculated mass of 5 g; it is planned to manufacture a dielectric substrate based on PDMS polymer with the addition of barium titanate. The issues of calculating the antenna parameters (measurement depth, resolution and distribution of radiation power over the volume of biological tissue, sensitivity, etc.) are considered. The research results and design parameters of the developed antenna demonstrated the effectiveness of the new antenna and the possibility of its adaptation to the object of research. Considering the presence of an ultra-wide band and miniature dimensions, the antenna can be a sensor of a multi-frequency multi-channel microwave radiothermograph.

A review of the effect of a microwave treatment on the production of activated carbon (AC) from agricultural waste is presented in this study. Although the thermal heating method is one of the most usual and applicable methods for the production of AC, this method has some disadvantages such as a thermal gradient from the surface to the interior of a particle, high cost of heating, long preparation time and fast firing. A microwave radiation method has been used recently by many researchers as an alternative method for heating. In this review, these two different methods of producing AC were compared. Previous studies on the preparation of AC using a microwave radiation method showed that the more significant parameters are the microwave radiation time, the microwave power level, the impregnation ratio and the agent flow rate. Accordingly, in this review, the effects of these parameters on the physical and chemical properties of AC, such as the pore structure, the adsorption capacity, the carbon yield and the surface functional groups, were discussed. In general, the physical properties of AC (adsorption capacity, pore volume and carbon yield) improved when these parameters were enhanced up to their optimum points, and then these properties decreased when these parameters were increased beyond their optimum values. The carbon/oxygen ratio was increased by the microwave method due to the elimination of acidic oxygen-containing functional groups on the surfaces of the ACs. © 2013 Elsevier B.V.

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A dual-mode slotted microstrip patch resonator is introduced in this paper for use
in wireless communication applications. The slot structure, etched inside the patch resonator, is
in the form of the 2nd iteration Koch fractal curve; using the conventional square microstrip patch
resonator as the initiator. Modeling and performance evaluation of the proposed ¯lter design have
been carried out using a method of moment based EM simulator, IE3D. Simulation results show
that the resulting resonator ¯lter has good transmission and return loss responses. The modeled
resonator has been found to possess a side length of about 0.22 the guided wavelength, which
represents a size reduction of about 81% as compared with that based on the conventional square
microstrip patch without slot. In addition, slits have been symmetrically etched in the external
edges of the patch structure, in an attempt to provide the resonator with tuning facility. Besides
the tuning possibility, these slits have been found to o®er further size reduction without worsening
the resulting ¯lter performance; providing the designer with more degrees of freedom.

This paper presents the design, simulation, and implementation of band pass filters in rectangular waveguides with radius, having 0.1 dB pass band ripple and 6.3% ripple at the center frequency of 14.2 GHz. A Mician microwave wizard software based on the Mode Matching Method (MMM) was used to simulate the structure of the filter. Simulation results are in good agreement with the measured one which improve the validity of the waveguide band pass filter design method.

This paper describes the design and simulation results of a new concept in power amplification called Syncrodyne power amplification. Here we describe the design procedure for our Series-3 power amplifier for GSM waveforms. The foundation of this design has its basis in a subset of nonlinear behavior called chaotic dynamics. Since the groundbreaking publication by Ott, Grebogi, and Yorke [1] on control of chaotic systems, a great deal of work has been done in communication using chaos [2] [3], weak signal detection [4], and synchronization [5], among many other things. We first reported on the formulation, simulation, and experimentation of the Syncrodyne amplification technique for a 2-MHz system [6], then proposed and simulated an 800-MHz design using a heterojunction bipolar transistor (HBT) [7]. Since then, we’ve developed a method to apply this technique for the power amplification of GSM waveforms. Figure 1 shows a block diagram of the Syncrodyne Power Amplifier. The general c...

The Substrate Integrated Waveguide (SIW) technology is an attractive approach for the design of high performance microwave and millimeter wave components, as it combines the advantages of planar technology, such as low fabrication costs, with the low loss inherent to the waveguide solution. In this study, a substrate integrated waveguide power divider, circulator and coupler are conceived and optimized in [10-15] GHz band by Ansoft HFSS code. Thus, results of this modeling are presented, discussed and allow to integrate these devices in planar circuits.

Abstract An analysis and design procedure are presented for a mode transducer which converts the rectangular TE10 mode into the circular TE01 mode. The field analysis leads to an explicit evaluation of the transducer's s matrix. An experimental model has been ...

— This paper presents the design of a CMOS low noise amplifier (LNA) with minimized group delay variations and optimized noise performance for ultra-wideband (UWB) applications. The proposed LNA employs a common source based current reuse topology. Through this configuration gain flatness of 12.25± 0.25 with noise figure (NF) less than 3.8 dB are achieved. This LNA achieves group delay variation of ±25 ps using the standard 0.18 µm CMOS technology. Weak Capacitive-Resistive shunt feedback technique is implemented across the input stage for wideband input matching. Series peaking with output resistive termination are adopted for group delay variations optimization. This UWB LNA has a measured 1dB compression point (P1dB) and an input third-order inter-modulation point (IIP3) of-7.0 dBm and 2.5 dBm respectively at 5.5 GHz. The implemented UWB LNA chip area is only 560 µm x 590 µm. Keywords — CMOS, group delay, low noise amplifier (LNA), ultra-wideband (UWB), current reuse, noise figure (NF), capacitive-resistive feedback, series peaking

Oil palm shell was used to prepare activated carbons by microwave irradiation and conventional heating methods using zinc chloride as the activation agent. The effects of the weight ratio of zinc chloride to palm shell on the textual and surface chemical properties of prepared activated carbon by both heating treatments were studied and compared in this study. The textual properties were investigated using nitrogen adsorption, ultimate and proximate analysis, and scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) was used to study the surface chemical properties. For both the microwave and conventionally prepared samples, the BET surface area was enhanced to a maximum at an impregnation ratio of 0.65 (Zn/palm shell) and then decreased with further increases in the chemical ratio. The total pore volume in the microwave samples increased continuously with increasing zinc chloride, while in the conventional samples, the total pore volume increased up to impregnation ratio of 0.65 and then decreased. The results showed that at the impregnation ratios of higher than 0.65, the rate of mesopore creation in microwave method is higher than that of conventional methods. FTIR spectra demonstrated that the CH stretching of the palm shell disappeared completely in the microwave samples, where it was only reduced in the case of the conventional samples as a result of the different types of heating. © 2013 Elsevier B.V. All rights reserved.

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A novel fractal dual-mode microstrip bandpass filter design has been introduced in an attempt to produce filters with highly miniaturized size for modern wireless applications. The filter structure has been generated based on the 3rd iteration Minkowski-like pre-fractal geometry, using the conventional dual-mode square ring resonator as the initiator in the fractal generation process. The space-filling property, self-similarity and the diagonal symmetry of the structures corresponding to the successive iteration levels of this fractal geometry have found to produce reduced size filter structures with accepted performance. The bandpass filter structure produced by the 3rd iteration of this fractal geometry can be considered as a novel design with adequate performance. This design structure possesses a size reduction of about 72% compared with the conventional dualmode square ring resonator operating at the same frequency and using the same substrate material. In addition, the new design technique seems reliable, since it provides the filter designers with more degree of freedom and further size reduction as compared with those reported in the literatures.