A 9-bit 2.9 GHz direct digital synthesizer MMIC with direct digital frequency and phase modulations

Abstract

This paper presents a low power, high speed SiGe DDS MMIC with 9-bit phase and 7-bit amplitude resolutions. This DDS MMIC is the first reported GHz range output DDS with direct digital frequency and phase modulation capabilities. Using more than eight thousand transistors, the DDS MMIC includes a 9-bit CLA accumulator for phase accumulation, a 9-bit CLA adder for phase modulation and a 7-bit sine-weighted DAC. The core area of the DDS occupies 1.7times2.0 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The DDS consumes low power of 2.0 W under a 3.3 V single power supply even with the added modulation blocks. The narrow band spurious-free-dynamic range (SFDR) is measured as 35 dBc with the maximum update frequency of 2.9 GHz. The DDS MMIC is packaged and tested in an LCC-44 cavity.