scholarly journals Reconfigurable ultra-wideband transmitter for generation of arbitrary impulse shapes and modulation schemes

2012 ◽  
Vol 10 ◽  
pp. 57-62
Author(s):  
A. T. Ott ◽  
C. J. Eisner ◽  
M. D. Blech ◽  
T. F. Eibert

Abstract. In this paper a reconfigurable ultra-wideband (UWB) impulse radio (IR) transmitter is presented. The IR signal is synthesized at an intermediate frequency (IF) by employing a multi-Nyquist digital-to-analog converter (DAC) with 12 bit resolution and an update rate of 2.3 GHz. Digital generation of signals in a field programmable gate array (FPGA) guarantees very high flexibility of the reconfigurable design. For upconversion to the radio frequency (RF) band, a first order bandpass (BP) sampling concept and an alternative conventional concept with mixer stages, have been realized. The system enables to generate signals with arbitrary modulation schemes and techniques at an external host personal computer (PC) employing MATLAB. Different measurements using a digitizing oscilloscope have been conducted to demonstrate the performance of the transmitter.

Author(s):  
С.В. Калиниченко ◽  
Ю.С. Балашов ◽  
Д.Г. Харин ◽  
А.С. Шнайдер

Представлен метод минимизации нелинейности передаточной характеристики прецизионного умножающего цифро-аналогового преобразователя (ЦАП) с помощью вспомогательного корректирующего ЦАП малой разрядности. В данном методе вспомогательный ЦАП формирует искаженную передаточную характеристику, которая в сумме с передаточной характеристикой основного ЦАП позволяет уменьшить результирующую интегральную и дифференциальную нелинейность. Коэффициенты коррекции, рассчитанные согласно представленному в статье алгоритму, однократно записываются в энергонезависимую память и преобразуются в управляющий сигнал для калибрующего ЦАП с помощью арифметико-логического устройства (АЛУ) в зависимости от входных данных. Для проведения экспериментальных исследований был разработан макет системы калибровки на основе программируемой логической интегральной схемы (ПЛИС) и демонстрационной платы с микросхемой двухканального 16-разрядного ЦАП с сегментированной структурой. Представлены экспериментальные результаты, которые показывают, что в данной системе коррекции собственная нелинейность калибрующего ЦАП не оказывает существенного влияния на итоговую передаточную характеристику. Приведенный алгоритм расчета коэффициентов позволяет эффективно уменьшить абсолютную интегральную и дифференциальную нелинейность 16-разрядного ЦАП до значений менее 1 единицы веса младшего разряда (ЕМР) In this paper, we present a method for nonlinearity minimization of precision multiplying digital-to-analog converter (DAC) by utilizing low resolution calibration DAC. In this method the calibration DAC generates distorted transfer characteristic which is added to the main DAC characteristic and provides resulting integral and differential nonlinearity reduction. The calibration coefficients are calculated following the presented algorithm and saved in nonvolatile memory and then are converted to controlling digital code of calibration DAC by arithmetical-logical unit (ALU) depending on input data. For experimental research we designed a model of calibration system based on field programmable gate array (FPGA) and a demo board with dual 16-bit segmented DAC. Then we give experimental results which show that inherent nonlinearity of calibration DAC does not significantly affect overall nonlinearity. The proposed calculation algorithm obtains effective integral and differential nonlinearity minimization of 16-bit DAC down to values of less than one least significant bit (LSB)


Serial Peripheral Interface or SPI is a synchronous serial communication protocol that provides full – duplex communication at very high speeds. It is a master – slave type protocol that provides a simple and low-cost interface between a microcontroller and its peripherals. This paper proposes the design of a priority-based master slave communication system using SPI Protocol that enables the system to operate using interrupts. The design mainly emphasizes on priority-based communication where the slaves will generate an interrupt over a newly defined interrupt pin when some data transfer needs to happen. When the master receives an interrupt from the slave it establishes communication with one slave at a time based on the priority and the priority to each slave is assigned by the arbiter or priority control block. The highest priority slave is served first. Shift register is used to store and transfer the data bit by bit and it resets every time a data transfer is complete. The design proposed here can be implemented in different applications which involve the peripherals that can support SPI protocol for communication such as LCDs, Analog to Digital Converter, Digital to Analog Converter, Memory Cards, Temperature Sensor, Pressure Sensor. In this work, a single master multi slave architecture is considered. The design given in this paper can be scaled up to support more than four slaves.


2020 ◽  
pp. 15-23
Author(s):  
V. M. Grechishnikov ◽  
E. G. Komarov

The design and operation principle of a multi-sensor Converter of binary mechanical signals into electrical signals based on a partitioned fiber-optic digital-to-analog Converter with a parallel structure is considered. The digital-to-analog Converter is made from a set of simple and technological (three to five digit) fiber-optic digital-to-analog sections. The advantages of the optical scheme of the proposed. Converter in terms of metrological and energy characteristics in comparison with single multi-bit converters are justified. It is shown that by increasing the number of digital-analog sections, it is possible to repeatedly increase the information capacity of a multi-sensor Converter without tightening the requirements for its manufacturing technology and element base. A mathematical model of the proposed Converter is developed that reflects the features of its operation in the mode of sequential time conversion of the input code vectors of individual fiber-optic sections into electrical analogues and the formation of the resulting output code vector.


Author(s):  
Divya Singh ◽  
Aasheesh Shukla

Background : Millimeter wave technology is the emerging technology in wireless communication due to increased demand for data traffic and its numerous advantages however it suffers from severe attenuation. To mitigate this attenuation, phased antenna arrays are used for unidirectional power distribution. An initial access is needed to make a connection between the base station and users in millimeter wave system. The high complexity and cost can be mitigated by the use of hybrid precoding schemes. Hybrid precoding techniques are developed to reduce the complexity, power consumption and cost by using phase shifters in place of converters. The use of phase shifters also increases the spectral efficiency. Objective: Analysis of Optimum Precoding schemes in Millimeter Wave System. Method: In this paper, the suitability of existing hybrid precoding solutions are explored on the basis of the different algorithms and the architecture to increase the average achievable rate. Previous work done in hybrid precoding is also compared on the basis of the resolution of the phase shifter and digital to analog converter. Results: A comparison of the previous work is done on the basis of different parameters like the resolution of phase shifters, digital to analog converter, amount of power consumption and spectral efficiency. Table 2 shows the average achievable rate of different algorithms at SNR= 0 dB and 5 dB. Table 3 also compares the performance achieved by the hybrid precoder in the fully connected structure with two existing approaches, dynamic subarray structure with and without switch and sub connected or partially connected structure. Table 4 gives the comparative analysis of hybrid precoding with the different resolutions of the phase shifter and DAC. Conclusion: In this paper, some available literature is reviewed and summarized about hybrid precoding in millimeter wave communication. Current solutions of hybrid precoding are also reviewed and compared in terms of their efficiency, power consumption, and effectiveness. The limitations of the existing hybrid precoding algorithms are the selection of group and resolution of phase shifters. The mm wave massive MIMO is only feasible due to hybrid precoding.


2021 ◽  
Vol 4 (3) ◽  
pp. 47
Author(s):  
Sergey M. Afonin

This work determines the coded control of a sectional electroelastic engine at the elastic–inertial load for nanomechatronics systems. The expressions of the mechanical and adjustment characteristics of a sectional electroelastic engine are obtained using the equations of the electroelasticity and the mechanical load. A sectional electroelastic engine is applied for coded control of nanodisplacement as a digital-to-analog converter. The transfer function and the transient characteristics of a sectional electroelastic engine at elastic–inertial load are received for nanomechatronics systems.


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