Multi-Nyquist-domain digital analog converter

Abstract

The invention discloses a multi-Nyquist-domain digital analog converter which comprises a K: 1LVDS parallel / serial converter, an encoder, a latch of integration return-to-zero control and a digital analog converter core unit based on an R-2R ladder network. The parallel / serial converter converts input N*K bits of low-speed data into N bits of high-speed data, wherein low M bits of data are directly sent to the latch without the need of passing through the encoder, high (N-M) bits of binary format data are coded into temperature code format data and output to the latch, and the latch generates return-to-zero switch control codes and non-return-to-zero control codes and outputs the return-to-zero switch control codes and the non-return-to-zero control codes to the digital analog converter core unit based on the R-2R ladder network. According to the multi-Nyquist-domain digital analog converter, the bandwidth of output signals can be expanded to a second Nyquist frequency domain and a third Nyquist frequency domain from a first Nyquist frequency domain under the circumstance that the working clock frequency of the digital analog converter is not improved, the output bandwidth of the digital analog converter is expanded greatly, and the power consumption of the digital analog converter under the identical output bandwidth is lowered greatly.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuit design, in particular to a multi-Nyquist domain digital-to-analog converter manufactured by using an InP / GaAsHBT (heterojunction bipolar transistor) process. Background technique [0002] Wideband high dynamic range digital-to-analog converters are widely used in RF signal transmission chains. Compared with the phase-locked loop frequency synthesizer, the direct digital frequency synthesizer has the advantages of fast frequency hopping time, continuous phase and easy digital modulation. The performance of the direct digital frequency synthesizer is often limited by its digital-to-analog converter module. With the development of radar digitization and multi-carrier wireless applications, the requirements for the bandwidth and dynamic range of digital-to-analog converters are getting higher and higher. [0003] In a traditional radio frequency transmission system, the baseb...

AI Technical Summary

Problems solved by technology

One of the main reasons for the complexity of the transmission system is the limitation of the bandwidth of the digital-to-analog converter

figure 1 It is a block diagram of a traditional digital-to-analog converter system. The traditional digital-to-analog converter can only provide good dynamic performance in the first Nyquist frequency domain, and its performance degrades rapidly as the output frequency increases.

At the same time, due to the sin(x) / x roll-off effect of the digital-to-analog converter, the system needs to add a SINC correction filter to achieve output power flattening, which further increases the system complexity

The output bandwidth and amplitude-frequency characteristics of traditional digital-to-analog converters severely restrict the performance of digital radio frequency transceiver systems

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