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Multistage amplifiers have become appropriate choices for high‐speed electronics and data conversion. Because of the large number of high‐impedance nodes, frequency compensation has become the biggest challenge in the design of multistage amplifiers. The new compensation technique in this study uses two differential stages to organize feedforward and feedback paths. Five Miller loops and a 500‐pF load capacitor are driven by just two tiny compensating capacitors, each with a capacitance of less than 10 pF. The symbolic transfer function is calculated to estimate the circuit dynamics and HSPICE and TSMC 0.18 μm. CMOS technology is used to simulate the proposed five‐stage amplifier. A straightforward iterative approach is also used to optimize the circuit parameters given a known cost function. According to simulation and mathematical results, the proposed structure has a DC gain of 190 dB, a gain bandwidth product of 15 MHz, a phase margin of 89°, and a power dissipation of 590 μW.

ABSTRACTThe improved three-dimensional imaging system by near-infrared light emission in breast tissue to more accurate diagnosis of tumour is presented in this paper. Based on the repeated experiments in this research, the result is that in this imaging system a more accurate diagnosis of abnormal area depends on the location of the sources and detectors. Therefore, an optimal location model has been proposed to a more suitable placement of sources and detectors. In this article, human samples with the breast cancer have not been examined due to the inaccessibility of three-dimensional imaging system by near-infrared lights. These experiments should have been conducted frequently for obtaining the more accurate reconstructed images, in order to evaluate the optical image reconstruction toolbox of NIRFAST 7.2 that has been coded in MATLAB programming environment and then the obtained results have been compared with the results of similar articles. The obtained results have shown that the proposed placement of sources and detectors has detected the abnormal area with a much lower error rate as well as the proposed placement of sources and detectors has provided a good result in simultaneous diagnosis of the two abnormal areas.

This study presents a novel multilayer structure of parallel coupled‐line bandpass filtercentered at 2.42 GHz with a fractional bandwidth value of approximately 19.4%. The designed filter can suppress harmonics with an appropriate frequency response by incorporating different techniques based on the multilayer technique. A combination of different techniques such as radial microstrip stubs and defected ground structure (DGS) and defected microstrip structure techniques are employed to suppress harmonics up to 5f0. These techniques are used in two layers to suppress up to 5f0. In addition, in this study, the effects of different parameters, such as the width of slot‐line DGS, the angle of diagonal line slots in the upper layer, and the air gap between the two layers on the filter performance, are investigated. To verify the correct circuit operation, the designed filter is implemented and tested. The measurement results of the proposed filter are compared with the simulation results.

This paper proposed a novel structure of a 10-bit, 400MS/s pipelined analog to digital convertor using 0.18 µm TSMC technology. In this paper, two stages are used to converter design and a new method is proposed to increase the speed of the pipeline analog to digital convertor. For this purpose, the amplifier is not used at the first stage and the buffer is used for data transfer to the second stage, in the second stage an amplifier circuit with accurate gain of 8 that is open loop with a new structure was used to speed up, also the design is such that the first 4 bits are extracted simultaneously with sampling. On the other hand, in this structure, since in the first stage the information is not amplified and transferred to the second stage, the accuracy of the comparator circuit should be high, therefore a new structure is proposed to design a comparator circuit that can detect unwanted offsets and eliminate them without delay, and thus can detect the smallest differences in input voltage. The proposed analog to digital convertor was designed with a resolution of 10 bits and a speed of 400MS/s, with the total power consumption 74.3mW using power supply of 1.8v.

ABSTRACTIn this paper, a new microstrip low-pass filter will be presented for achieving high ability to choose wide stopband and suitable operation. This filter is built after design and simulation, and results of measurement will confirm the design accuracy. The results show that the overall performance of the recommended structure is improved in terms of physical dimensions, sharpness of response, and width of stopband, compared to old structures. Cut-off frequency of filter is 1.1 GHz. The stopband is so wide, and the amount of weakness in this band is equal to −20 dB. Roll-off rate parameter of the proposed filter is equal to 240 dB/GHz. This means that changing filter condition moves rapidly from passing to stop state. Size of proposed filter is small and equal to 27 mm × 16 mm. Results of simulation and measurement of the fabricated sample exhibit the same reaction.