Design and implementation of VXI bus Arbitrary Waveform Generator

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.

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.

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.

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

In this paper, we propose a low-cost arbitrary waveform generator to simulate battery voltage transients specified by ISO 16750–2 voltage profiles. The proposed methodology is based on the technique of direct digital synthesis (DDS) implemented in a microcontroller. The proposed approach allows reducing the amount of Flash memory used by the lookup table. The device generates several types of waveforms and uses a sequencer to combine them into the desired voltage profile. For testing purposes, emulations of the variations on the cranking voltage and the superimposed A.C. voltage are used to validate the proposed solution.

This paper presents a novel completely scaling-free CORDIC algorithm in rotation mode for hyperbolic trajectory. We use most-significant-1 bit detection technique for micro-rotation sequence generation to reduce the number of iterations. By storing the sinh/cosh hyperbolic values at octant boundaries in a ROM, we can extend the range of convergence to the entire coordinate space. Based on this, we propose a pipeline hyperbolic CORDIC processor to implement a direct digital synthesizer (DDS). The DDS is further used to derive an efficient arbitrary waveform generator (AWG), where a pseudo-random number generator modulates the linear increments of phase to produce random phase-modulated waveform. The proposed waveform generator requires only one DDS for generating variety of modulated waveforms, while existing designs require separate DDS units for different type of waveforms, and multiple DDS units are required to generate composite waveforms. Therefore, area complexity of existing designs gets multiplied with the number of different types waveforms they generate, while in case of proposed design that remains unchanged. The proposed AWG when mapped on Xilinx Spartan 2E device, consumes 1076 slices and 2016 4-input LUTs. The proposed AWG involves significantly less area and lower latency, with nearly the same throughput compared to the existing CORDIC-based designs.

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.

Arbitrary Waveform Generator (AWG) is an important signal generation module in many applications such as communication and mixed signal testing. This paper describes an AWG based on Direct Digital Frequency Synthesizer (FFDS). The CORDIC algorithm with an iterative process and a pipeline plus parallel structure are used to implement the AWG whose frequencies and amplitudes of sinusoid waveforms in the arbitrary wave can be controlled by frequency control words (FCWs), initial vectors of CORDIC module respectively. Compared to the conventional AWG, it is flexible and saves much hardware.

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.

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.

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.

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.

The two-dimensional MEMS scanning mirror is the core component in laser radar. It can obtain high quality imaging, based on its advantages of high resolution, fast imaging speed, small size and low price. A two-dimensional MEMS scanning mirror control method based on direct digital synthesizer is presented in this paper. This circuit achieves the phase accumulator of double direct digital synthesizer with FPGA, and directly realizes all kinds of frequency modulation of arbitrary waveform directly by digital method. In order to improve the drive performance of the two-dimensional MEMS scanning mirror, a 5th-order elliptic function filter is used to filter the sinusoidal driving signal of direct digital synthesizer. Testing results indicate that the proposed method of arbitrary waveform generator based on direct digital synthesizer can drive the two-dimensional MEMS scanning mirror with the characteristics of high scanning control precision and wide scanning range.

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.

: 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.