Title :
A quadrature baseband approach to direct digital FM synthesis
Author :
van Rooyen, G.-J. ; Lourens, J.G.
Author_Institution :
Dept. of Electr. & Electron. Eng., Stellenbosch Univ., South Africa
fDate :
9/1/2000 12:00:00 AM
Abstract :
The use of direct digital synthesis (DDS) to synthesize high-frequency analog signals has received much attention over the past decade. This technique allows modulation schemes such as FM and PM to be implemented with high fidelity using digital components. This paper investigates an improvement on the typical DDS approach of synthesizing the desired signal at an intermediate frequency. Instead, two quadrature baseband signals are generated, which are then mixed directly to the output center frequency. This method can be used to synthesize FM signals of arbitrarily high output frequency, using digital circuitry with considerably lower clock speeds
Keywords :
direct digital synthesis; frequency modulation; DDS; PM; clock speeds; digital circuitry; digital components; direct digital FM synthesis; high fidelity; high output frequency; high-frequency analog signals synthesis; intermediate frequency; modulation; output center frequency; quadrature baseband signals; Baseband; Circuit synthesis; Clocks; Digital modulation; Equations; Frequency modulation; Frequency synthesizers; Sampling methods; Signal generators; Signal synthesis;
Journal_Title :
Broadcasting, IEEE Transactions on