توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Design of a Low Power Distributed Broadband 9–31 GHz HEMT Mixer
نویسنده(ها): ،
اطلاعات انتشار: دوازدهمین کنفرانس دانشجویی مهندسی برق، سال
تعداد صفحات: ۵
millimeter–wave HEMT distributed mixer covering the RF frequency range from 9 to 31 GHz with IF frequencies from 10 to 80 MHz is presented. By employing uniform artificial transmission lines with charge injection technique, the proposed mixer demonstrates broadband characteristics at high microwave frequencies with maintaining high Conversion Gain and low DC power consumption.
With a local oscillator power of 12 dBm, and RF power of –20 dBm, the proposed mixer has a Conversion Gain of –1.5 ~ 2 dB (without IF signal amplification), Noise Figure of 8.5 ~ 14.5 dB and 17 mW DC power consumption over a broadband frequencies from 9–31 GHz. Mixer operation is demonstrated both for downconversion to fixed IF and for broadband conversion using fixed LO frequencies. The simulated LO–to–RF isolation is better than 13 dB for overall operating frequency band. The topology of this mixer is suitable for monolithic implementation<\div>

۲Design of a Broadband HEMT Mixer for UWB Applications
نویسنده(ها):
اطلاعات انتشار: کنفرانس بین المللی پژوهش های کاربردی در فناوری اطلاعات، کامپیوتر و مخابرات، سال
تعداد صفحات: ۶
This paper presents the design of a novel distributed HEMT mixer for ultrawide–band (UWB) receivers. Artificial transmission lines are incorporated in the distributed mixer to absorb the parasitic capacitances. With a local oscillator power of 12 dBm, and RF power of –20 dBm, the proposed mixer has a Conversion Gain of 0 ~ 4 dB(without IF signal amplification), LO–to–RF isolation better than 32 dB and 130 mW DC power consumption. The designed mixer is capable of covering the RF and LO frequencies over a wide range of frequencies from 5–25 GHz. Mixer operation is demonstrated both for downconversion to fixed IF and for broadband conversion using fixed LO frequencies. This mixer utilized a new distributed topology with single–gate HEMTs and achieved a vary broadband performance comparable to the cascode or dual–gate distributed mixers. The topology of this mixer is suitable for monolithic implementation.<\div>

۳An Improvement of Steerable Pyramid denoising method
نویسنده(ها):
اطلاعات انتشار: Iranian Journal of Electrical and Electronic Engineering، دوازدهم،شماره۱، Mar ۲۰۱۶، سال
تعداد صفحات: ۷
The use of wavelets in denoising, seems to be an advantage in representing well the details. However, the edges are not so well preserved. Total variation technique has advantages over simple denoising techniques such as linear smoothing or median filtering, which reduce noise, but at the same time smooth away edges to a greater or lesser degree. In this paper, an efficient denoising method based on Total Variation model (TV), and Dual–Tree Complex Wavelet Transform (DTCWT) is proposed to incorporate both properties. In our method, TV is employed to refine low–passed coefficients and DTCWT is used to shrink high–passed noisy coefficients to achieve more accurate image recovery. The efficiency of our approach is firstly analyzed by comparing the results with well–known methods such as probShrink, BLS–GSM, SUREbivariate, NL–Means and TV model. Secondly, it is compared to some denoising methods, which have been reported recently. Obtained results convince us that the proposed scheme provides a better performance in noise blocking among reported state–of–the–art methods.
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