نشریه صنایع الکترونیک
سال دوازدهم شماره 3 (پیاپی 47، پاییز 1400)

In this paper, the co-design of integrated low noise amplifier (LNA) and limiter with noise matching of matching network between Low noise amplifier and limiter for minimizing system noise figure is presented. The design procedure of low noise amplifier for minimum noise figure and 15 dBm power gain at center frequency and limiter block for 5 watt (37dBm) input power handling and optimization of matching network to reach minimum noise figure and maximum power transmission from limiter to low noise amplifier is discussed in detail and the result is compared with same blocks but by considering 50 ohm matching network between limiter and Low noise amplifier. Also band-pass filter is used in system output to filtering the out of band unwanted signals and prevent noise to be produced in next blocks. The mentioned method have been used for design and implementation of integrated circuit of limiter and low noise amplifier based on 0.25 AlGaAs/InGaAs pHEMT technology and 25dB signal filtering of 1 GHz out of band. Finally the simulation and measured data is demonstrated.

Channel sharing strategy through Media Access Control (MAC) protocols for avoiding collision is a challenging issue in Ad hoc networks. Deploying two distinct approaches, Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) and Wireless Token Ring Protocol (WTRP) play pivotal roles in MAC sublayer management. These protocols have been used in a variety of networks ranging from Internet of Things (IoT) to low rate tactical links in High Frequency (HF) band. In this paper, we investigate the operational algorithms of CSMA/CA and WTRP protocols and compare them via simulation in NS-3 simulator. The two protocols are evaluated and the appropriate protocol in terms of delay and throughput is chosen for networks with varying load, which is affected by node and packet number. Our results show that in networks with light load where high throughput is warrantied, CSMA/CA outperforms WTRP in terms of delay. However, algorithm of WTRP leads to higher throughput in networks with heavy traffic.

Shaking simulation table is one of effective tools for analysis of the structures' behavior against earthquake input. The most important part of this table is a control system that tracks displacement profile, velocity and acceleration of a real earthquake using encoder and accelerometer sensors. However, some uncertainties, such as changing inertia of the table regarding installation of different structures on it, the dynamics that are not modeled, and the table sensors' noise cause decrease in precision of the control system. To solve these problems, in this paper the performance of this simulated table is improved by combining the output of sensors using an evolutionary adaptive filters EKF and UKF and two series PID controllers. In the proposed method, evolutionary adaptive filters EKF and UKF is used to decrease uncertainties and sensors' noise and also for estimation of the table parameters. PID controllers use the linear velocity estimated by the filters to stabilize, track the reference input, and remove the external disturbances of the table. The performance of the proposed method is evaluated in a simulated environment and laboratory test. The result shows the effectiveness of the proposed method.

This paper presents a new ultra low power CMOS Ultra Wide Band (UWB) mixer. To reduce the supply voltage and the power consumption, the bulk injection technique is used. Adopting PMOS transistors in the mixer core enhances the noise due to bulk injection topology. On the other hand, to increase the conversion gain, we use a gm-boosting buffer in the IF stage of our design. To achieve an ultra-low power circuit, the transistors in the mixer core are biased in weak inversion region. The proposed circuit is designed and simulated in TSMC 0.18um CMOS technology. Then, the layout is designed and the post-layout simulations are performed using the foundry design kit. The post-layout simulation results revels maximum conversion gain of 10.9 dB, minimum noise figure of 13.9 dB and IIP3 if 4 dBm, with 2dBm LO power, in 3~11 GHz band. The port to port isolation is better than 43 dB. The total power consumption is 214 uW with 1V supply.

Condition Monitoring (CM) and Fault Detection of wind turbines will increase the reliability and availability of the turbine. One of the most common types of wind turbines is the DFIG type with a back-to-back converter. The IGBT open-circuit fault rate of the converter is significant compared to the total fault rate in the wind turbine. The IGBT open-circuit fault of the wind turbine converter will cause a defect in the current output of the converter, resulting in reduced wind turbine output performance. In order to fault-tolerant control in back-to-back converters, an accurate and fast method of open-circuit fault detection is required. In this paper, the IGBT open-circuit fault for DFIG wind turbine back-to-back converter using a new method detected and isolated focusing on increasing speed and accuracy. The proposed method is Low cost and it does not require extra sensors and hardware to detection and isolation of the fault. The fault diagnostic method is based on Feature-Level fusion. To evaluate the proposed structure, a simulation setup based on real data of a 2.5 MW turbine is used. Simulations result showed the effectiveness and robustness of the proposed method in the detection of single and multiple simultaneous and non-simultaneous faults in a different LEG or single LEG of the grid side and rotor side converter.

In this paper, a novel microwave narrow notch-band and band-pass filters using composite right-left handed (CRLH) structure for WLAN application are proposed. The proposed filters have been designed by using a unit-cell which is called z-shaped unit-cell. By using the z-shaped unit-cell near the microstrip line, a narrow notch-band at 5.7 GHz has been occurred while by utilizing a series interdigital capacitor, a narrow band-pass filter at 5.7 GHz has been occurred. According to the Metamaterial concept, the proposed one- and two-stage narrow notch-band and band-pass filters have been designed and simulated. The equivalent circuit model and full-wave simulation results of the proposed band-pass filters are developed. To validate the design concept, the designed two-stage band-pass filter has been fabricated and tested. Experimental verification is provided and a good agreement has been found between the simulation and measurement. The proposed filters have many advantages in terms of compact size, high selectivity, low insertion loss, and easy integration with other planar technologies. The total size of the proposed one- and two-stage filters are 0.40 λg × 0.17 λg and 0.40 λg × 0.35 λg respectively.