scholarly journals Experimental Study of Noise Temperature and Conversion Loss of SIS Junction Mixers

1986 ◽  
Vol 39 (3) ◽  
pp. 379 ◽  
Author(s):  
JC Macfarlane ◽  
LB Whitbourn ◽  
RA Batchelor

Experiments on the performance of superconductor-insulator-superconductor (SIS) tunnel junctions as heterodyne mixers at 40 GHz are reported. The techniques developed for the fabrication of multi-junction SIS series arrays differ from, and are considerably simpler than, other methods described in the literature. Results are reported on mixer noise temperature, conversion loss, saturation, local oscillator power levels and mixer dynamic range. Factors affecting the mixer's conversion performance are identified and comparisons are made with other reported results. It is concluded that mixer performance in the present experiments is limited by imperfect impedance matching at the signal frequency, due to relatively large values of parasitic capacitance in the junctions. Future work is aimed at both reducing the junction capacitance and redesigning the mixer mount to give improved r.f. matching.

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2112
Author(s):  
José M. Pérez-Escudero ◽  
Carlos Quemada ◽  
Ramón Gonzalo ◽  
Iñigo Ederra

In this paper the design and experimental characterization of a combined doubler-subharmonic mixer based on Schottky diodes which uses a 75 GHz MMIC based local oscillator is presented. This solution integrates in the same substrate the doubler and the mixer, which share the same metallic packaging with the local oscillator. The prototype has been fabricated and measured. For characterization, the Y-Factor technique has been used and the prototype yields a best conversion loss and equivalent noise temperature of 11 dB and 1976 K, respectively, at 305 GHz. This performance is close to the state of the art, and shows the potential of this approach, which allows a significant reduction in terms of size and volume.


2021 ◽  
Vol 11 (16) ◽  
pp. 7238
Author(s):  
José M. Pérez-Escudero ◽  
Carlos Quemada ◽  
Ramón Gonzalo ◽  
Iñigo Ederra

In this paper the design and experimental validation of a fourth-harmonic mixer based on Schottky diodes working around 300 GHz is presented. The main novelty of this work consists in the integration of an MMIC-based local oscillator, working around 75 GHz, and a mixer in the same metallic block housing. A prototype has been characterized using the Y-Factor method and yields a best measured conversion loss and an equivalent noise temperature of 14 dB and 9600 K, respectively. This performance is comparable to the state-of-the-art for this type of mixer.


2013 ◽  
Vol 22 (03) ◽  
pp. 1350008 ◽  
Author(s):  
GORAN JOVANOVIĆ ◽  
DARKO MITIĆ ◽  
MILE STOJČEV ◽  
DRAGAN ANTIĆ

One approach to design self-tuning gm-C biquad band-pass filter is considered in this paper. The phase control loop is introduced to force filter central frequency to be equal to input signal frequency what is achieved by adjusting the amplifier transconductance gm. Thanks to that, the filter is robust to parameter perturbations and it can be used as a selective amplifier. In the full tuning range, it has a constant maximum gain at central frequency as well as a constant bandwidth. The 0.25 μm SiGe BiCMOS technology was used during design and verification of the band-pass filter. The filter has 26 dB gain, quality factor Q = 20 and central frequency up to 150 MHz. Simulation results indicate that the total in-band noise is 59 μV rms , the output third intercept point OIP3 = 4.36 dB and the dynamic range is 35 dB. Maximal power consumption at 3 V power supply is 1.115 mW.


2014 ◽  
Vol 23 (01) ◽  
pp. 1450004 ◽  
Author(s):  
XIAOBO XUE ◽  
XIAOLEI ZHU ◽  
QIFENG SHI ◽  
LENIAN HE

In this paper, a 12-bit current-steering digital-to-analog converter (DAC) employing a deglitching technique is proposed. The deglitching technique is realized by lowering the voltage swing of the control signal as well as by using a method of glitch counteraction (GC). A new switch–driver structure is designed to enable the effectiveness of the GC and provide sufficient driving capability under a low supply voltage. Moreover, the control signal's rise/fall asymmetry which increases the glitch error can be suppressed by using the proposed switch–driver structure. The 12-bit DAC is implemented in 180 nm CMOS technology. The measurement results show that the spurious free dynamic range (SFDR) at low signal frequency is 78.8 dB, and it is higher than 70 dB up to 60 MHz signal frequency at 400 MS/s. The measured INL and DNL are both less than ±0.6 LSB.


2010 ◽  
Vol 168-170 ◽  
pp. 1295-1298
Author(s):  
Ming Li Sun ◽  
Hai Rong Cui ◽  
Bin Wang ◽  
Shuang Lu

The paper presents an inclination transducer with magnetic fluid, being dedicated to measure little inclination angles in comparison with a horizontal or a vertical plane. The functioning principle is submitted. The results of theory analysis show that output voltage of sensor and inclination angles are linear dependence. The factors affecting the sensor sensitivity are inspected, which include the exciting signal frequency, the peak voltage and the susceptibility of magnetic fluid.


Author(s):  
Shubham Dubey ◽  
Biro Piroska ◽  
Manjulata Gautam

The world is changing rapidly, so is academics. E-learning has altered the area of academics and education. ICT enabled learning has given ideal services to students by providing any type of content on demand which is proportional to the performance of students. The concentration of learner has been found instinctive; thus there is a need of engaging mind towards course progress with its entirety till the objectives of the course will be achieved. There are several e-learning platforms available as EdX, Udacity, Khan Academy, Alison those have a number of learners registered for various courses. Studies suggest that these platforms suffer from the common problem of learners’ dropping out. Investigations also claim early leaving rate is increasing due to lack of quality of content, distraction factors, learners’ mind change, outdated and succinct information, and some more detraction factors. These issues have been observed on the basis of early leaving rates in various MOOCs. Thus there is a mammoth scope for minimizing the impact of these reasons on the learners’ mind. It can be achieved by identifying these factors affecting learners’ motivation during the course. This study is aiming on identifying these factors. The approach is to explore some certain keywords on previous literature (total 41) and then calculating their frequencies and co-factors associated with them. Both grouped factors contribution and individual factor contribution have been taken care. The study gives a direction for future work towards overcoming these actor and engaging learners in ICT enabled learning.


1994 ◽  
Vol 48 (6) ◽  
pp. 649-654 ◽  
Author(s):  
George R. Agnes ◽  
Gary Horlick

The quantitative aspects of elemental electrospray mass spectrometry are investigated with particular emphasis on the factors affecting the ability to establish linear calibration curves. It is shown that linear calibration curves can be obtained for trace elements if the analyte signal is ratioed to the signal from a constant amount of a similarly charged electrolyte species. Linear calibration curves can be established over a concentration dynamic range of at least four orders of magnitude. The added component seems to function as a stabilizer and monitor of the electrospray process and as an internal standard. In certain cases, species generated by acidification of the solvent may be used as electrospray stabilizers.


2018 ◽  
Vol 27 (09) ◽  
pp. 1850142 ◽  
Author(s):  
Mehdi Bandali ◽  
Omid Hashemipour

A two-dimensional digital-to-analog converter (DAC) structure compatible with dynamic element matching (DEM) methods is presented. Unlike the DACs using segmented structure for employing DEM, the new structure randomizes inter-segment error. This advantage is achieved because of the characteristics of the algorithm of two-dimensional decoding. The simulation results in 180[Formula: see text]nm CMOS technology, 319.72[Formula: see text]MHz signal frequency and 800[Formula: see text]MS/s sample rate for an 8-bit two-dimensional DAC utilizing the presented structure, shows 14.94[Formula: see text]dB spurious-free dynamic range (SFDR) improvement compared to the SFDR of the same DAC without employing the presented structure. Also, the IMD3 of the DAC employing the presented structure for [Formula: see text][Formula: see text]MHz and [Formula: see text][Formula: see text]MHz is 50.1[Formula: see text]dB.


Author(s):  
Tran Van Hoi ◽  
Ngo Thi Lanh ◽  
Nguyen Xuan Truong ◽  
Nguyen Huu Duc ◽  
Bach Gia Duong

<p>This paper focuses on the design and implementation of a front-end for a Vinasat satellite receiver with auto-searching mechanism and auto-tracking satellite. The front-end consists of a C-band low-noise block down-converter and a L-band receiver. The receiver is designed to meet the requirements about wide-band, high sensitivity, large dynamic range, low noise figure. To reduce noise figure and increase bandwidth, the C-band low-noise amplifier is designed using T-type of matching network with negative feedback and the L-band LNA is designed using cascoded techniques. The local oscillator uses a voltage controlled oscillator combine phase locked loop to reduce the phase noise and select channels. The front-end has successfully been designed and fabricated with parameters: Input frequency is C-band; sensitivity is greater than -130 dBm for C-band receiver and is greater than -110dBm for L-band receiver; output signals are AM/FM demodulation, I/Q demodulation, baseband signals.</p>


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