A novel ultra-HIGH compliance, low power, very accurate and HIGH OUTPUT IMPEDANCE current OUTPUT stage (COS) with extremely HIGH OUTPUT current drive capability is proposed in this paper. The principle of operation of this unique structure is discussed, its most important formulas are derived and its outstanding performance is verified by HSPICE simulation in TSMC 0.18mm CMOS, BSIM3, and Level49 technology.This deliberately composed structure utilizes a well combination (for a mutual auto control action) of negative and positive feedbacks to achieve ever demanded merits such as very low power of 150mW, ultra HIGH ratio of 3000 for OUTPUT current over the bias current (which is selected to be 0.5mA) at low THD of -20dB and very HIGH OUTPUT IMPEDANCE of 5GWwith power supplies of ±0.5V when operating at class AB mode. Simulation results with ±0.5V power supply shows an absolute OUTPUT voltage dynamic range of 0.9V which interestingly provides the HIGHest yet reported OUTPUT voltage compliance for Current mode building blocks implemented by regular CMOS technology. Full process, voltage, and temperature variation (PVT) analysis of the circuit is also investigated in order to approve the well robustness of the structure. The transient stepwise response is also done to verify the proposed COS stability.

In this paper, a new feeding structure is applied in the patch antenna design to overcome undesirable features of the earlier multilayer feeding structures while maintaining their interesting features.To more readily understand the operation mechanism of proposed feeding structure, an efficient circuit model has been also presented.It is known that proximity and aperture coupled feeding structures are sensitive to the transverse feed point location. In contrast, the proposed feeding architecture is very easy to fabricate and it overcomes the alignment difficulties arising from the proximity and aperture coupled feeding structures. The CST simulation results, analytic results and measurement ones show good agreement with each other. Moreover, a new miniaturization technique which is based on using HIGH IMPEDANCE Wire (HIW) structures has been introduced. Due to their artificial HIGH permeability properties, using proposed method, someone may miniaturize conventional patch antenna without bandwidth and efficiency corruption. Applying suggested method to the proposed antenna structure, two different feeding structures have been designed and compared. Finally, by using AMC structures to load HIW, more miniaturization factor has been achieved.

This paper presents the analysis and design of an asymmetrical directional coupler (ADC) with arbitrary source and load IMPEDANCEs. The microstrip-coupled-line structure is analyzed and its IMPEDANCE matrix is first obtained. Its transmission matrix is then determined. The transmission matrix of multi-section ADC is then obtained using its properties. Finally, the total transmission matrix is converted to the IMPEDANCE matrix and then its scattering matrix is derived. The method of least squares (MLS) is applied for the design of ADC. An error function is constructed based on the scattering parameters of ADC, which is a function of its geometrical dimensions. The minimization of the error function determines its dimensions (namely widths and lengths of line sections and their spacings) by writing a software in MATLAB using the Genetic Algorithm (GA) and Conjugate Gradient Algorithm (CGM). The HFSS Full Wave Software is applied to finalize the optimum design of the ADC configuration. An example of the ADC is designed, fabricated (on the substrate ROGERS 4003) and measured as the proof of concept. Its coupling coefficient is 6 dB, frequency band is 5. 2-6. 2 GHz, terminal IMPEDANCEs are 50, 50, 75 and 100 Ohms.

The low fault current of HIGH-IMPEDANCE faults (HIFs) is one of the main challenges for the protection of distribution networks. The inability of conventional overcurrent relays in detecting these faults results in electric arc continuity that it causes the fire hazard and electric shock and poses a serious threat to human life and network equipment. This paper presents ​ an HIF detection algorithm based on quantifying the nonlinear and asymmetry features of HIF waveforms. To this end, first, the substation current is sampled and then, the superimposed component of cross entropy signal calculated by comparing two subsequent half cycles of the current signal is determined as the HIF detection criteria. On the other hand, to overcome the challenge of the similar transient of device switching and HIF, the time duration of transient continuity is considered as the constraint of the proposed algorithm. The proposed scheme satisfactory works in the presence of nonlinear loads and does not need for training dataset, transformations, and calculation of harmonic and symmetrical components. The effectiveness of the proposed HIF detection algorithm is demonstrated using the time-domain simulation of IEEE 13 node test system.

In this paper, a new method for detecting HIGH IMPEDANCE fault in distribution networks is presented. In the proposed method, the Stationary Wavelet Transform (SWT) is used to extract features. Disturbance detection algorithm in the network, using changes in selected features in the data windows after the fault occurrence, compared with the data windows before the fault occurrence, detects the HIGH IMPEDANCE fault. It also uses the vote-based decision-making system based on the aggregation of the OUTPUT of the PNN classification and the use of three post-disturbance data windows, has been improved the reliability of the proposed method. The results of the proposed method for detecting HIGH IMPEDANCE fault on the 34-node IEEE in the EMTP-RV software indicate the accuracy, reliability, and security of the proposed method at a HIGH level.

This paper proposes a new method for extracting dynamic properties for HIGH IMPEDANCE fault (HIF) detection using discrete Fourier transform (DFT). Unlike conventional methods that use features extracted from data windows after fault to detect HIGH IMPEDANCE fault, in the proposed method, using the disturbance detection algorithm in the network, the normalized changes of the selected features are used to compare the data windows after the fault occurrence and before the fault occurrence. It also uses the post-disturbance data windows, develops a decision system based on the OUTPUT of the support vector machines (SVM) classifier, and compares the amount of certainty of other network events with HIGH IMPEDANCE fault. The reliability and security of the proposed method have been improved. The proposed method is implemented on an IEEE 34 bus network in EMTP-RV software. The simulation results show 97. 2% accuracy, 98. 5% reliability, and 98. 8% security.

A power divider (PD)/ power combiner (PC) with HIGH quality factor and enhanced OUTPUT ports isolation using substrate integrated waveguide (SIW) technology is proposed. An SIW cavity is designed to provide a HIGH quality factor filtering response and an SMD resistor is attached between two OUTPUT ports to realize the HIGH isolation. The value of the applied resistor is calculated by using the even and odd mode analysis. The measured results obtained from testable model are in good agreement with the simulated results. These results show that the return loss is 23 dB, the minimum insertion loss is 4. 55 dB including intrinsic 3 dB insertion loss of PD, and the isolation between OUTPUT ports is 20 dB, which shows that the proposed design could be an important component in microwave circuits.

This paper presents a new approach for detection of HIGH IMPEDANCE faults in the Electric power distribution systems using wavelet transform. The proposed method has been implemented on a digital protective relay and its behavior is investigated using appropriate simulation software. Details of the design procedure, implementation and the results of performance studies of the proposed relay are given in this paper. The experiment shows that the proposed algorithm performs very well in detecting a HIGH IMPEDANCE fault with nonlinear arcing resistance. It is clearly shown that the proposed relay is able to accurately distinguish between HIGH IMPEDANCE faults and other cases such as load and/or capacitance switching.