A fast-hopping single-PLL 3-band MB-OFDM UWB synthesizer

This paper describes a 3-band (mode 1) multi-band-OFDM UWB synthesizer implemented in a 0.25-mum SiGe BiCMOS process. The interference-robust, fast-hopping synthesizer uses one single-sideband (SSB) mixer for frequency shifting. A single phase-locked loop (PLL) generates the steady input signals for the SSB-mixer. Crucial in the design is a divide-by-5 frequency divider that generates quadrature signals at a frequency of 528 MHz. The 0.44 mm² fully integrated synthesizer consumes 52 mW from a 2.7 V supply. Out-of-band spurious tones are below -50 dBc, allowing co-operability with WLAN applications in the 2.4 GHz and 5 GHz range. The integrated phase noise is below 2deg rms. The measured frequency transition time is well below the required 9.5 ns