Digital chirp waveform generator and method

摘要

A chirp waveform generator for producing a chirp waveform ƒ(t)=sin (t² modulus m) where modulus m is represented by n submoduli and/or factored submoduli m₁-m_n. Sequence generators generate digital sequence values representative of sequences of quadratic residues for each submoduli and/or factored submoduli m₁-m_n. Sine and cosine digital-to-analog converters (DACs) connected to the sequence generators receive the digital sequence values for each submoduli and/or factored submoduli m₁-m_n and produce sequences of corresponding analog sine and cosine signals. An analog processor including adders and multipliers connected to the DACs combines the sine and cosine signals to produce the chirp waveform. The argument (t² modulus m) is an implemented phase argument that approximates a desired phase argument (πrt²). Programmable inputs on the sequence generators enable control over waveform parameters including starting phase, ramp rate and frequency.