Ping-pong Mode Research Articles

A high-speed transient waveform sampling SCA ASIC prototype in 180 nm CMOS technology

Switched capacitor array (SCA) is an important method of waveform digitization in high-energy physics experiments. This paper presents the design and test results of an eight-channel SCA ASIC for high-speed waveform sampling. The ASIC is designed and fabricated in 180 nm CMOS technology. The sampling rate of up to 14.25 Gsps is achieved by adopting the proposed dual-chain interpolating delay cell in DLL. The ASIC can be configured to operate in two modes: long-chain mode for deeper sampling depth and ping-pong mode for recording two waveforms in a short time. The bandwidth is over 1.1 GHz. By optimizing the sampling order, the distortion caused by the bandwidth discontinuity is reduced. Deep N-well is adopted to isolate the interference between digital and analog signals. The test results show that the random noise is approximately 0.87 mV RMS after the fixed-pattern noise correction. The time resolution is better than 5 ps RMS over the time measurement range of approximately 73μs.

A Switched Capacitor Waveform Digitizing ASIC at Cryogenic Temperature for HPGe Detectors

This article presents the design and evaluation of the first cryogenic switched capacitor array (SCA)-based waveform digitizer (CryoSCA) for HPGe detectors for low-background physics experiments. The chip has integrated 16 channels and was fabricated using a 0.18- μm CMOS process with modified BSIM3v3 model parameters at 77 K. Each channel employs two 32-cell sample blocks working in the ping-pong mode, a 256-cell storage array, 32 parallel Wilkinson-type ADCs with 12-bits dynamic range, and registers. The chip was fully evaluated and showed promising performance at 300 K and 77 K. The measured power consumption of each channel increased from 3.3 mW at 300 K to 3.6 mW at 77 K. The averaging integral nonlinearity (INL) over 1-V dynamic range was measured to be 0.3% and 0.2% at 300 K and 77 K, respectively. The static noise decreased from 0.8 mV at 300 K to 0.6 mV at 77 K. The leakage current decreased from 18.2 fA at 300 K to 2.2 fA at 77 K.

GERO: a general SCA-based readout ASIC for micro-pattern gas detectors with configurable storage depth and on-chip digitizer

The paper presents GEneral ReadOut (GERO), a general readout ASIC based on a switched capacitor array for micro-pattern gas detectors. It aims at providing general readout electronics for low-to-medium event-rate gas detectors with high sampling frequency, configurable storage depth, and data digitalization. The first prototype GERO chip integrates 16 channels and was fabricated using a 0.18-µm CMOS process. Each channel consists of a sampling array working in a ping-pong mode, a storage array with a 1024-cell depth, and 32 Wilkinson analog-to-digital converters. The detailed design and test results are presented in the paper.

A New Methodology for Rice Area Monitoring With COSMO-SkyMed HH–VV PingPong Mode SAR Data

In this paper, a novel approach is proposed to exploit a time series of COSMO-SkyMed (CSK) HH-VV SAR images to map rice fields and to estimate the sowing dates. The approach relies on multi-polarization features, i.e., the squared modulus of the HH and VV channels and the polarization ratio, extracted from CSK SAR scenes. The key step consists of extracting a rice training signature related to the multipolarization features. This signature allows estimating the sowing date that, at once, is used to refine the rice map obtained by the conventional interpretation of the CSK time series in terms of the scattering mechanisms of the different growing cycles. Experiments, carried out on a time series of 32 CSK images, collected from the Mekong Delta region, South Vietnam, confirm the soundness of the proposed methodology which is shown to provide results comparable to the ones obtained by a literature approach that exploits a similar dataset.

On boundaries of ping-pong modes in multipacting

Multipactor is an avalanche multiplication of the number of electrons in radio-frequency devices due to secondary electron emission. One of the possible modes of this kind of discharge was studied in detail and was named “a ping-pong mode” in a publication by R. A. Kishek [Phys. Rev. Lett. 108, 035003 (2012) and Phys. Plasmas 20, 056702 (2013)]. In the present paper, I show that conditions of stability and cutoff limits are quite different from those derived in the cited papers.

COSMO-SkyMed HH/VV PingPong Mode SAR Data to Discriminate Among Sea, Urban, and Vegetated Areas

In this study, the sensitivity of COSMO-SkyMed (CSK) dual-polarimetric HH/VV Synthetic Aperture Radar (SAR) data with respect to sea, vegetated, and urban areas is investigated. A dual polarimetric feature, namely the complex correlation between the copolarized channels, is introduced to exploit the inherent peculiarities of the CSK incoherent dualpolarization PingPong mode for distinguishing the three scenarios. The dual-pol feature is contrasted with the correlation between the HH and VV amplitudes, the copolarized ratio, and with conventional single-pol ones, namely the HH and VV intensities.

A new architecture of open CNC system based on compiling mode

Nowadays, the research of open CNC system based on PC has been the main focus of open CNC system technology. To improve the real-time performance of open CNC system, the embedded real-time OS such as RTX is widely used. However, there still remain several problems such as high development cost and difficulty and long-term investment cycle when adopt this method. On the other hand, the traditional interpretive mode to process G codes could bring some disadvantages, for example, limitation of interpolation algorithm. In this paper, a new kind of compiled-typed open CNC system is brought up. The architecture compiles the whole G codes into the object codes which are executable for the control system in the common Windows operating system and uses Ping-Pong mode to store object codes in the lower computer to lower the real-time requirement for the upper computer. Then the system prototype is developed, and the feasibility of compiled-typed CNC system is verified.

Coastline Extraction Using Dual-Polarimetric COSMO-SkyMed PingPong Mode SAR Data

A two-step physically consistent procedure is proposed to exploit COSMO-SkyMed (CSK) synthetic aperture radar (SAR) data acquired in the incoherent dual-polarization PingPong mode. The first step, which deals with land/sea discrimination, is accomplished in a robust and effective way by exploiting the inherent peculiarities of the CSK PingPong mode. Hence, a dual-polarization scattering model that relates the correlation between the HH and VV CSK polarimetric channels to the coherence time of the observed scene is first proposed. The second step, which deals with the extraction of the continuous coastline, is accomplished by a simple image processing that consists of extracting intermediate frequency components using two Gaussian-shaped filters. Experiments undertaken over actual CSK single-look slant range complex PingPong HH/VV SAR data show the physical soundness of the proposed rationale and the processing effectiveness.

Design and Implementation of Low-Power Hardware Architecture With Single-Cycle Divider for On-Line Clustering Algorithm

A dual-stage hardware architecture that supports two kinds of moving averages for the on-line clustering algorithm is proposed. The architectural design of this work is different from the one of previous works that focus on the iterative clustering algorithm. The system includes a set of memories that operates in ping-pong mode, so that the Manhattan distances can be computed when the centroids are updated. The high-throughput parallel divider in the moving-average engine is a new solution to reduce the computational time of one division operation to a single clock cycle and to calculate cumulative moving averages with no precision loss. Two hardware examples show the robustness of the proposed architecture, and the architectural analysis is performed with the 90 nm CMOS technology. In the first example, the gate count is the smallest and the normalized power consumption of this work is the lowest among previous works. In the second example, the architecture is compared with related works, which implement the Self-Organizing Map (SOM) algorithm. The proposed work has high flexibility for parameter combinations and can achieve high performance for color quantization in a single iteration. The functionalities of the proposed system are also verified with the background subtraction application.

On the COSMO-SkyMed PingPong Mode to Observe Metallic Targets at Sea

A dual-polarimetric model to exploit X-band COSMO-SkyMed (CSK) dual-polarimetric PingPong mode synthetic aperture radar (SAR) data for metallic target observation purposes is first developed. The model relates the correlation between the copolarized channels, in case of sea surface with and without metallic targets, to the time offset between bursts related to the HH and VV polarimetric channels. Following this theoretical rationale, a constant false alarm rate (CFAR) approach is implemented to first exploit CSK PingPong full-resolution SAR data for target observation purposes. Experiments undertaken over a large data set of COSMO-SkyMed single look complex slant (SCS) PingPong HH/VV SAR data demonstrate the physical soundness of the approach and its effectiveness from an operational viewpoint. A whole CSK SAR scene is processed in about 10 s. Furthermore, the dual-polarization approach is also compared with a conventional single-polarization CFAR one and it is shown to perform best.

A single-fiber WDM local access network based on amplified LED transceivers

A potentially low-cost local access network is proposed and demonstrated. It provides point-to-point individual links carried by a single optical fiber between a central office and a passive router distributing the links to the users. The system is based on high-power LEDs, spectral slicing, wavelength division multiplexing (WDM), and frequency routing. Each link is terminated at both ends by a single optical device transmitting and receiving alternatively according to the so-called ping-pong mode. Such an arrangement simplifies significantly the implementation of multiple access systems.

CAMAC modules for recording arbitrarily long time series

Two CAMAC modules have been designed to record the time of arrival of up to 32768 sequential events. the system consists of a clock module to generate a gated clock pulse train and a memory module to record event arrival time. Two memory modules can be operated in ping-pong mode to capture a time series of indefinite length, limited only by the capacity of the data acquisition computer storage medium. The maximum clocking frequency of 25 MHz provides a minimum digitization period of 40 ns and an inter-event deadtime of 2 clock cycles. these circuits have been used in a number of experiments for a wide variety of time measurements. They are particularly suited for interpolating event occurences relative to high precision UTC time signals distributed by satellites. A synchronized output pulse has also been provided to allow an external time-to-digital converter to determine event arrival time relative to the clock phase. This permits time-of-flight measurements over long baselines with a fraction of a nanosecond accuracy.