scholarly journals A Novel 183 GHz Solid-State Sub-Harmonic Mixer

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 186 ◽  
Author(s):  
Guangyu Ji ◽  
Dehai Zhang ◽  
Jin Meng ◽  
Siyu Liu ◽  
Changfei Yao
Keyword(s):  
Solid State ◽  
Three Dimensional ◽  
Local Oscillator ◽  
Conversion Loss ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Harmonic Mixer ◽  
Electromagnetic Model ◽  
Single Sideband ◽  
Rf Performance

This paper proposes a novel sub-harmonic mixing topology. Based on the proposed topology and the precise three-dimensional electromagnetic model of the Schottky barrier diode; a novel 183 GHz solid-state sub-harmonic mixer is designed and measured. By adding a compact low-pass filter near the ground of the mixer’s circuit, the effect on the mixer’s RF performance of the random error of the conductive adhesive in assembling is effectively decreased. The test results show that the optimal single-sideband conversion loss of the mixer is 8.1dB@183GHz when the local oscillator signal is 4mw@91GHz. In the RF bandwidth from 173 GHz to 191 GHz, the single-sideband conversion loss is less than −10.6 dB. At the same time, the RF port return loss is less than 9.8 dB.

Models of the Bouguer gravity and geologic structure at Yucca Flat, Nevada

Geophysics ◽  
1988 ◽  
Vol 53 (2) ◽  
pp. 231-244 ◽  
Author(s):  
John F. Ferguson ◽  
Roger N. Felch ◽  
Carlos L. V. Aiken ◽  
John S. Oldow ◽  
Holly Dockery
Keyword(s):  
Structural Information ◽  
Three Dimensional ◽  
Structural Features ◽  
Bouguer Gravity ◽  
Three Dimensional Model ◽  
Geologic History ◽  
The West ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

The Bouguer gravity anomaly at Yucca Flat, Nevada, has been modeled by two different techniques: the Cordell‐Henderson and Parker‐Oldenburg methods. The three‐dimensional model has incorporated known density and structural information where possible. These models predict the structural relief on the Cenozoic‐Paleozoic contact to within 150 m or about 15 percent of the actual depth. The three‐dimensional Parker‐Oldenburg method has been found to be efficient in an application involving a large (9000 sample) data base. Numerical stability was ensured by the application of a consistent regularization (a low‐pass filter tuned to suppress the noise‐dominated portion of the data spectrum) of the downward continuation operator. The use of a single regularizing filter for the entire model is not completely satisfactory due to the oversmoothing of shallow regions of the basin. The model is useful in the delineation of the geologic history of the area. Structural features in the model support the hypothesis that regional stress fields rotated significantly during the Tertiary. Major structural elements of the basin are well defined on the Cenozoic‐Paleozoic interface. The principal basin‐bounding fault is the large‐throw Carpetbag fault on the west. This fault was most active during the earliest phases of subsidence. The Yucca fault is seen to be a much smaller feature in the model presented here. The basin is rotated down to the west, with normal hinge faults on the eastern margin.

Attenuation of Gas Pulsation in a Reciprocating Compressor Piping System by Using a Volume-Choke-Volume Filter

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Boxiang Liu ◽  
Jianmei Feng ◽  
Zhongzhen Wang ◽  
Xueyuan Peng
Keyword(s):  
Characteristic Frequency ◽  
Pressure Pulsation ◽  
Natural Frequencies ◽  
Three Dimensional ◽  
Piping System ◽  
Reciprocating Compressor ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Response Characteristics ◽  
Low Pass

This paper presents an investigation of the use of a volume-choke-volume low-pass filter to achieve gas pulsation attenuation in a reciprocating compressor piping system, with a focus on its frequency response characteristics and influence on the actual attenuation effects. A three-dimensional acoustic model of the gas pulsation was established for a compressor discharge piping system with and without the volume-choke-volume filter, based on which the gas column natural frequencies of the piping system and the pressure wave profiles were predicted by means of the finite element method. The model was validated by comparing the predicted results with the experimental data. The results showed that the characteristic frequency of the filter was sensitive to both diameter and length of the choke but independent of the parameters of the piping beyond the filter. It is worth noting that the characteristic frequency of the filter constituted one order of the gas column natural frequencies of the piping system with the filter. The pressure pulsation levels in the piping system downstream of the filter could be significantly attenuated especially for the pulsation components at frequencies above the filter’s characteristic frequency. The measured peak-to-peak pressure pulsation at the outlet of the filter was approximately 61.7% lower than that of the surge bottle with the same volume.

Canal-Otolith Interactions After Off-Vertical Axis Rotations I. Spatial Reorientation of Horizontal Vestibuloocular Reflex

2000 ◽  
Vol 83 (3) ◽  
pp. 1522-1535 ◽  
Author(s):  
Karin Jaggi-Schwarz ◽  
Hubert Misslisch ◽  
Bernhard J. M. Hess
Keyword(s):  
Semicircular Canal ◽  
Three Dimensional ◽  
Head Tilt ◽  
Vertical Axis ◽  
Longitudinal Axis ◽  
The Body ◽  
Spatial Transformation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Spatial Reorientation

We examined the three-dimensional (3-D) spatial orientation of postrotatory eye velocity after horizontal off-vertical axis rotations by varying the final body orientation with respect to gravity. Three rhesus monkeys were oriented in one of two positions before the onset of rotation: pitched 24° nose-up or 90° nose-up (supine) relative to the earth-horizontal plane and rotated at ±60°/s around the body-longitudinal axis. After 10 turns, the animals were stopped in 1 of 12 final positions separated by 30°. An empirical analysis of the postrotatory responses showed that the resultant response plane remained space-invariant, i.e., accurately represented the actual head tilt plane at rotation stop. The alignment of the response vector with the spatial vertical was less complete. A complementary analysis, based on a 3-D model that implemented the spatial transformation and dynamic interaction of otolith and lateral semicircular canal signals, confirmed the empirical description of the spatial response. In addition, it allowed an estimation of the low-pass filter time constants in central otolith and semicircular canal pathways as well as the weighting ratio between direct and inertially transformed canal signals in the output. Our results support the hypothesis that the central vestibular system represents head velocity in gravity-centered coordinates by sensory integration of otolith and semicircular canal signals.

Research on the Short-Time Bias Stability of the Solid Vibration Beam Gyroscope

2011 ◽  
Vol 179-180 ◽  
pp. 86-91
Author(s):  
Xian Lin Bai ◽  
Yong Le Lu ◽  
Yu Liu
Keyword(s):  
Solid State ◽  
Output Signal ◽  
Transient Solution ◽  
Short Term ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Bias Stability ◽  
Low Pass ◽  
Simulation And Experiment ◽  
Short Time

In this paper, Short-term bias stability of solid state vibration beam gyroscope is studied. Based on the dynamical equation of solid vibration beam gyroscope, the elements effecting the zero stability which effects the short term bias stability was discussed. The computed result shows that the main factors for short-term bias stability is transient solution error. The output signal has been filtered by the low pass filter, according to the characteristic of transient solution error. Simulation results demonstrate that low-pass filter can effectively suppress the error of output signal. In addition, the signal of solid state vibrating gyroscope filtered by low-pass filter agrees well with the simulation result. From the simulation and experiment data, the validity of the model and the feasibility of the filtering programs has been proved.

scholarly journals A Novel Sample Based Quadrature Phase Shift Keying Demodulator

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Asraf Mohamed Moubark ◽  
Sawal Hamid Md Ali
Keyword(s):  
Phase Noise ◽  
Signal To Noise Ratio ◽  
Local Oscillator ◽  
Coherent Detection ◽  
Signal Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Incoming Signal ◽  
Shift Keying ◽  
Low Pass

This paper presents a new practical QPSK receiver that uses digitized samples of incoming QPSK analog signal to determine the phase of the QPSK symbol. The proposed technique is more robust to phase noise and consumes up to 89.6% less power for signal detection in demodulation operation. On the contrary, the conventional QPSK demodulation process where it uses coherent detection technique requires the exact incoming signal frequency; thus, any variation in the frequency of the local oscillator or incoming signal will cause phase noise. A software simulation of the proposed design was successfully carried out using MATLAB Simulink software platform. In the conventional system, at least 10 dB signal to noise ratio (SNR) is required to achieve the bit error rate (BER) of 10−6, whereas, in the proposed technique, the same BER value can be achieved with only 5 dB SNR. Since some of the power consuming elements such as voltage control oscillator (VCO), mixer, and low pass filter (LPF) are no longer needed, the proposed QPSK demodulator will consume almost 68.8% to 99.6% less operational power compared to conventional QPSK demodulator.

scholarly journals Digital Filtering of Three-Dimensional Lower Extremity Kinematics: an Assessment

2013 ◽  
Vol 39 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Jonathan Sinclair ◽  
Paul John Taylor ◽  
Sarah Jane Hobbs
Keyword(s):  
Lower Extremity ◽  
Repeated Measures ◽  
Three Dimensional ◽  
Digital Filtering ◽  
Camera Motion ◽  
Optimal Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Kinematic Analyses ◽  
Analysis System

Abstract Errors in kinematic data are referred to as noise and are an undesirable portion of any waveform. Noise is typically removed using a low-pass filter which removes the high frequency components of the signal. The selection of an optimal frequency cut-off is very important when processing kinematic information and a number of techniques exists for the determination of an optimal frequency cut-off. Despite the importance of cut-off frequency to the efficacy of kinematic analyses there is currently a paucity of research examining the influence of different cut-off frequencies on the resultant 3-D kinematic waveforms and discrete parameters. Twenty participants ran at 4.0 m•s-1 as lower extremity kinematics in the sagittal, coronal and transverse planes were measured using an eight camera motion analysis system. The data were filtered at a range of cut-off frequencies and the discrete kinematic parameters were examined using repeated measures ANOVA’s. The similarity between the raw and filtered waveforms were examined using intra-class correlations. The results show that the cut-off frequency has a significant influence on the discrete kinematic measure across displacement and derivative information in all three planes of rotation. Furthermore, it was also revealed that as the cut-off frequency decreased the attenuation of the kinematic waveforms became more pronounced, particularly in the coronal and transverse planes at the second derivative. In conclusion, this investigation provides new information regarding the influence of digital filtering on lower extremity kinematics and re-emphasizes the importance of selecting the correct cut-off frequency.

scholarly journals Enhancing SNR and generating contrast for cryo-EM images with convolutional neural networks

2020 ◽  
Author(s):  
Eugene Palovcak ◽  
Daniel Asarnow ◽  
Melody G. Campbell ◽  
Zanlin Yu ◽  
Yifan Cheng
Keyword(s):  
Image Processing ◽  
High Frequency ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Low Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Processing Pipeline ◽  
Visual Contrast ◽  
Low Pass

AbstractIn cryogenic electron microscopy (cryo-EM) of radiation-sensitive biological samples, both the signal-to-noise ratio (SNR) and the contrast of images are critically important in the image processing pipeline. Classic methods improve low-frequency image contrast experimentally, by imaging with high defocus, or computationally, by applying various types of low-pass filter. These contrast improvements typically come at the expense of high-frequency SNR, which is suppressed by high-defocus imaging and removed by low pass filtration. Here, we demonstrate that a convolutional neural network (CNN) denoising algorithm can be used to significantly enhance SNR and generate contrast in cryo-EM images. We provide a quantitative evaluation of bias introduced by the denoising procedure and its influences on image processing and three-dimensional reconstructions. Our study suggests that besides enhancing the visual contrast of cryo-EM images, the enhanced SNR of denoised images may facilitate better outcomes in the other parts of the image processing pipeline, such as classification and 3D alignment. Overall, our results provide a ground of using denoising CNNs in the cryo-EM image processing pipeline.

scholarly journals A Wideband Subharmonic Mixer Incorporating Signal Interference Technique Based Isolation Circuit

2019 ◽  
Vol 9 (2) ◽  
pp. 132-136
Keyword(s):  
Intermediate Frequency ◽  
Local Oscillator ◽  
Signal Interference ◽  
Frequency Range ◽  
Conversion Loss ◽  
Large Signal ◽  
Third Order ◽  
Single Sideband ◽  
Down Conversion ◽  
Intercept Point

A broadband (8.7 GHz – 11.5 GHz) performing passive sub-harmonic down-conversion mixer using signal interference technique (SIT) is demonstrated, designed and reported in this paper. The local oscillator (LO) frequency is half of the radio frequency (RF) for the 2xsub-harmonic mixer architecture; therefore, for the RF lying in the range 8.7 GHz to 11.5 GHz, required LO frequency range is 4.25 GHz to 5.65 GHz with 0.2 GHz fixed intermediate frequency (IF). With a broadband operation, designed prototype shows single sideband down-conversion loss in the range 9.6 dB – 12.6 dB. Moreover, large-signal testing infers an adequate linear trait of the proposed design, showing -3 dBm and 11.32 dBm for the 1 dB compression point and third order input intercept point, respectively.

scholarly journals A 560 GHz Sub-Harmonic Mixer Using Half-Global Design Method

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 234
Author(s):  
Bo Zhang ◽  
Yong Zhang ◽  
Liucheng Pan ◽  
Yu Li ◽  
Jianhang Cui ◽  
...  
Keyword(s):  
Design Method ◽  
Intermediate Frequency ◽  
Local Oscillator ◽  
Conversion Loss ◽  
Harmonic Mixer

In this paper, a 560 GHz terahertz sub-harmonic mixer using a new half-global design method is reported. This method combines the advantages of the subdivision design method and the global design method, and greatly enhances the abilities of the optimization of matching variables while retaining the portability of the unit circuit. When the local oscillator (LO) frequency was fixed with 3 mW power at 280 GHz, average up-conversion double sideband (DSB) conversion loss of 8 dB with intermediate frequency (IF) power of −5 dBm was achieved.

scholarly journals Design and Measurement of a 0.67 THz Biased Sub-Harmonic Mixer

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 161
Author(s):  
Guangyu Ji ◽  
Dehai Zhang ◽  
Jin Meng ◽  
Siyu Liu ◽  
Changfei Yao
Keyword(s):  
Glass Substrate ◽  
Schottky Diodes ◽  
Local Oscillator ◽  
Center Frequency ◽  
Measured Signal ◽  
Quartz Glass Substrate ◽  
Conversion Loss ◽  
Side Band ◽  
Harmonic Mixer ◽  
Series Configuration

To effectively reduce the requirement of Local Oscillator (LO) power, this paper presents the design and measurement of a biased sub-harmonic mixer working at the center frequency of 0.67 THz in hybrid integration. Two discrete Schottky diodes were placed across the LO waveguide in anti-series configuration on a 50 μm thick quartz-glass substrate, and chip capacitors were not required. At the driven of 3 mW@335 GHz and 0.35 V, the mixer had a minimum measured Signal Side-Band (SSB) conversion loss of 15.3 dB at the frequency of 667 GHz. The typical conversion loss is 18.2 dB in the band of 650 GHz to 690 GHz.

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