ADC Production Test Technique Using Low‐Resolution Arbitrary Waveform Generator

Testing of a read channel for hard disk drives (HDD) requires an extremely high-speed arbitrary waveform generator (AWG) to emulate Lorentzian waveforms for read functional tests. If a sampling rate required to the AWG exceeds the maximum available rate of the instrument, a possible solution is to use two AWG's together running at the same rate synchronously and generating signal alternately to make their equivalent sampling rate doubled. One of the key components of such interleaving AWG is a high-speed analog selector. However it is not easy to find a good selector in ultra high frequency range. An application note proposes a practical solution that is a pseudo interleaving AWG. It is a variation of traditional signal combining method using a power combiner instead of a high-speed selector. This paper describes about performance analysis and experimental results of the pseudo interleaving compared to a true interleaving. Data stored in two AWG's are created with the same method as the true interleaving AWG. The data are simply distributed alternately into each AWG. The results show that the pseudo interleaving works well in spite of its simple structure and can be useful for generating Lorentzian waveforms

The arbitrary waveform generator plays a very important role in the design and testing of electronic products, and the virtual instrument provides a new direction for the development of arbitrary waveform generator. The traditional waveform generator is improved by LabVIEW in the paper, and the virtual arbitrary waveform generator is designed by the graphical programming.The system can generate the common basic function signals, generate arbitrary waveform signal through superposition of signal and addition of noise signal, and realize the signal storage and transmission. It can easily realize the continuous upgrading and improvement of the system function and output of the customized signal waveform, and provide convenience for design and measurement.

Comprehensive waveform generation is an important functional component of automated test equipment (ATE). Waveform generators synthesize signal stimuli to be applied to a device under test (DUT). As military and commercial electronics become increasingly complex, more sophisticated signal stimuli are required. ATE requires signal stimuli varying from advanced communication signals to the playback of captured real-world analog signals. Waveform generators can synthesize signals that can be broadly categorized into four types: standard functions, advanced functions, arbitrary waveforms, and waveform sequences. Standard functions include the simple sine, square, triangle, pulse, and ramp waveforms. Advanced functions include complex signals such as multi-tone, AM, FM, sinc pulse, haversine, half-cycle sine, Gaussian pulse, Lorentz pulse, noise and others. Arbitrary waveforms involve the point-by-point user-defined waveform synthesis. Waveform sequences provide a mechanism to piece together standard or arbitrary waveforms in stages to create a user-defined compound waveform. Example applications for each of these four waveform categories are described in this paper. Modern waveform generators are extremely powerful, but can also add significant complexity for the user. The arbitrary waveform generator, an instrument found in most ATE systems, is a very powerful signal synthesis tool. Unfortunately, many users take advantage of only a small fraction of the powerful features available to them in an arbitrary waveform generator. Also, selecting the right arbitrary waveform generator can be daunting when comparing specifications such as DAC resolution, clock rates and topology, memory depth, sequencing, sweeping, triggering and synchronization. This paper describes the technical differences between various signal generation techniques, presents the signal fidelity impact of clock topology, discusses dynamic range limitations due to noise, accuracy and resolution, and provides typical applications to illustrate signal generation usage. Ultimately, this information should help the user avoid common pitfalls in applying waveform generators within ATE.

The paper design a good performance arbitrary waveform generator with AD’s digital-analog chip AD760 as the core. Thesis mainly research hardware and software design of computer-controlled arbitrary waveform generator for the corresponding. Hardware part of the arbitrary waveform generator take Cygnal’s high-speed micro-controller C8051F310 micro-controller as the controller and AD760 circuit components of the design. We carried out anti-jamming design when hardware design, Including filtering, spare part handling of input pin, grounded, the power handling. The paper also describes a total distortion of periodic arbitrary waveform definition and evaluation process and methods, the energy is calculated using the time domain distortion, and the influence of the measurement system itself is compensated. This method can be used for arbitrary waveform generator arbitrary waveform distortion for accurate measurement and measurement calibration.

Based on the detailed analysis of the Virtual instrument technology and Arbitrary Waveform Generator technology, Arbitrary Waveform Generator module based on VXI bus is discussed. The design principle and realization method of Arbitrary Waveform Generator based on VXI bus are given, which involved in VXI bus register based interface and Direct Digital Synthesis, furthermore, Arbitrary Waveform Generator module based on VXI bus is developed successfully. The experiment shows that the developed Arbitrary Waveform Generator based on VXI bus can generate the normal waveform and the arbitrary waveform, and can implement the adjustment of frequency, amplitude and phase.

Today a growing number of applications in design engineering, production and environmental testing, and system service require specific analog waveforms and digital patterns. Such requirements are neither satisfactorily nor easily met by the use of standard function or single purpose, custom generators. Traditional methods of waveform generation suffer from undesirable complexity or mediocre performance and are otherwise limited. For the majority of arbitrary waveform generation applications, including medical engineering, modal analysis and electronic engineering, direct digital synthesis techniques are satisfactory. Direct digital synthesis, based generally on periodic retrieval of predetermined amplitude values, may be used to 2 generate such waveforms. Within the limits imposed by the system's maximum sample rate and the Nyquist criteria, any waveform may be produced using these techniques. The objective of this inquiry, within a particular set of constraints, is to extend the cost/performance envelope of direct digital synthesis techniques for the generation of arbitrary waveforms. Performance is enhanced, particularly in the areas of output bandwidth and signal purity.

In order to improve the output power of laser pulse in the inertia confinement fusion experiment, an arbitrary waveform generator is fabricated to shape the laser pulse. The arbitrary waveform generator is based on the impedance tapered micro-strip line technology and GaAs Field Effect Transistor set which has a good ability of generating voltage-controlled current. With the impedance tapered micro-strip line technology, the arbitrary waveform generator generates shaping electrical pulse with duration less than 10 ns, 330 ps time-domain adjustment. We use the shaping electrical pulse to modulate semiconductor laser which has the characteristic of direct modulate, the experiment results show the shaped laser pulse is obtained based on the shaping electrical pulse.

A new software-defined S-band radar (SDSR) has recently been developed at the Air Force Research Laboratory. The system is built upon individual off-the-shelf components, devices, and instruments, and the center of the architecture is an Arbitrary Waveform Generator (AWG). The AWG can be programmed to generate various kinds of radar waveforms, which are mixed with a carrier to create S-band radar signals. The AWG can be interfaced with a computer which runs on MatLab or LabView for software definition of radar waveforms. Furthermore, the computer can be connected to the Internet for receiving data from remote users. As a result, the new SDSR can be used to support studies of radar waveforms in a large area by remote users. The characteristics of the radar system are studied and the performance of the system is optimized by selecting the parameters of the building components. The newly developed SDSR is used to test the wavelet-based radar waveforms, which verifies the theoretical results produced earlier.

The Arbitrary Waveform Generator (AWG) is an important instrument that is widely used in automatic test equipment, radar system, and other fields for generating complex signals. The increasing demand for waveform's complexity is consisted of repeatable segments and advanced-segments, where each segment or segments group could be repeated multiple times. Those requirements make the existing design, implemented by an address generator, complex. The software defined technology can separate the instruction sequence processing from the Data plane to the Controller where the complex logic is defined by software, which lead to a simplified data plane. This paper proposes a design that will generate complex arbitrary waveform by decoupling the waveform composing logic in address generator out from the data plane as an instruction controller. The controller support instruction sequence defined by segment and a jump instruction, which can implement the repeatable segments and the advanced-segments, respectively. We built an AWG based on this design and made the implementation in a field programmable gate array with a required clock frequency of 125 MHz. The design has a high sampling rate of 4 gigabit samples per second and can generate complex arbitrary waveform consisting of repeatable segments and advanced-segments.

We are developing an arbitrary waveform generator (AWG) to provide enhanced capability for radar applications. The current design accommodates two waveform generators on a single unit for dual frequency operation. The basic architecture of this unit employs a field programmable gate array (FPGA) and a high speed and high precision digital to analog converter (DAC) for direct digital synthesis. This AWG is capable of up to 450 MHz bandwidth with ability for frequency notching. Phase fidelity of better than 1.2/spl deg/ deviation RMS is also achievable. This AWG operates with lower power consumption as compared with other waveform generators, which is advantageous for future spaceborne applications. This will enable radars to return higher precision data, to be reduced in complexity, and to operate in any band without interfering with dedicated bandwidths.

In this paper, we verified an arbitrary waveform generator based on a nonlinear transmission line (NLTL). The fabricated arbitrary waveform generator consists of a NLTL harmonic generator, 10dB coupled line couplers, Wilkinson power dividers, band pass filters, low noise amplifiers (LNA), variable attenuators, and NLTL phase shifters. By controlling the bias voltage of attenuators and phase shifters, it is possible to generate a desired arbitrary waveform such as a triangle waveform and a sawtooth waveform in a microwave frequency range.

: By combing the ultra-fast ( 100 GHz) near-ballistic uni-traveling carrier photodiode (NBUTC-PD) and advanced optical pulse shaper system, we demonstrate the photonic generation and detection of (near) real-time arbitrary waveform at W-band with ultra-high time-bandwidth product. By use of such setup, remote-ranging (5 meters) at Wband with fine resolution ( 5 mm), has also been successfully achieved.

Photonic generation and processing of microwave arbitrary waveforms has been a topic of interest recently. Compared with the electronic techniques, photonics techniques provide the capabilities of generating and processing high-frequency and large-bandwidth microwave waveforms which cannot be fulfilled by the electronic techniques, In this paper, techniques to generate and process microwave arbitrary waveforms in the optical domain using advanced fiber Bragg gratings (FBGs) are reviewed, with an emphasis on the system architectures in which FBGs are employed as spectral shapers or optical filters. The challenges in using FBGs for microwave arbitrary waveform generation and processing are also discussed.

We propose and experimentally demonstrate a photonic approach to generating a chirped microwave waveform with a large time-bandwidth product (TBWP) based on self-heterodyne technique. We use the chirp characteristic of a distributed feedback (DFB) laser (LD) to generate a frequency-modulated optical pulse, to directly modulate the LD using an injection current with a parabolic current shape that is controlled by a microwave waveform generated by a low-speed arbitrary waveform generator (AWG). The frequency-modulated optical waveform is then sent to an unbalanced Mach-Zehnder interferometer (MZI) to get two time-delayed replicas of the input waveform. A chirped microwave waveform is then generated by beating the time-delayed waveforms at a high speed photodetector (PD). The proposed technique is theoretically studied and experimentally demonstrated. Using an AWG with sampling rate of 100 MS/s and an MZI with an arm length difference of 144 m, we experimentally generate a linearly chirped microwave waveform with a long time duration of 1 μs and a bandwidth of 4.2 GHz, with a TBWP of 4200.

Benefitting from a large bandwidth and compact configuration, a time-domain pulse-shaping (TPS) system provides possibilities for generating broadband radio frequency (RF) arbitrary waveforms based on the Fourier transform relationship between the input–output waveform pair. However, limited by the relatively low sampling rate and bit resolution of an electronic arbitrary-waveform generator (EAWG), the diversity and fidelity of the output waveform as well as its reconfiguration rate are constrained. To remove the EAWG’s limitation and realize dynamic real-time reconfiguration of RF waveforms, we propose and demonstrate a novel approach of RF arbitrary-waveform generation based on an improved TPS system with an integrated dual parallel Mach–Zehnder modulator (DPMZM) and multi-tone inputs. By appropriately adjusting the DC bias voltages of DPMZM and the power values, as well as the center frequencies of the multi-tone inputs, any desired RF arbitrary waveform can be generated and reconfigured in real time. Proof-of-concept experiments on the generation of different user-defined waveforms with a sampling rate up to 27 GSa/s have been successfully carried out. Furthermore, the impact of modulation modes and higher-order dispersion on waveform fidelity is also discussed in detail.