A Pulse Shaping Technique for Spur Suppression in Injection-Locked Synthesizers

作者：Izad Mehran M^*; Heng Chun Huat

来源：IEEE Journal of Solid-State Circuits, 2012, 47(3): 652-664.

DOI：10.1109/JSSC.2011.2177178

• Injection-locked oscillator (ILO)
• pulse shaping
• spur suppression
• sub-harmonic injection locking

Frequency synthesizers based on sub-harmonic injection-locked oscillators can reduce power and area effectively. However, they suffer from unwanted side-bands caused by undesirable harmonics in the injection pulse. This paper presents a pulse shaping technique that reduces these undesirable harmonics in the injection pulse and produces low-spur synthesized output. The robustness of the proposed technique and the impact of circuit non-idealities are also discussed in depth. A test chip tailored to the first band group of WiMedia UWB is fabricated in 0.13-mu m CMOS technology to verify the effectiveness of this technique. Experimental results show that the proposed pulse shaping attenuates the spurs by 22 dB and suppresses them below -47 dBc. The prototype achieves a switching time of less than 4.7 ns and phase noise of -122 dBc/Hz@1 MHz offset at 4.488 GHz. The chip occupies an active area of 0.15 mm(2) and draws only 18 mA from a 1.2-V supply.

• 出版日期2012-3