A digital frequency synthesizer for a 2.4 GHz fast frequency hopping transceiver

Abstract

In this paper, a compact architecture of a digital frequency synthesizer for a 2.4 GHz fast frequency hopping radio modem is presented. The synthesizer is designed for generating 12-bit quadrature carrier signals from 50 to 90 MHz in 500 kHz steps. The phase-to-amplitude conversion is performed with a look-up table which is compressed by using the fact that only a limited set of discrete frequencies is needed. Simulation and synthesis results for a VHDL-implementation of the architecture are given. In addition, the proposed architecture is compared to a traditional look-up based direct digital frequency synthesizer with similar performance.