A Pulse Shaping Technique for Spur Suppression in Injection-Locked Synthesizers
A Pulse Shaping Technique for Spur Suppression in Injection-Locked Synthesizers
复制标题
注入锁定合成器中抑制杂散的脉冲整形技术
DOI：
10.1109/jssc.2011.2177178
复制
发表时间：
2012
影响因子：
5.4
通讯作者：
C. Heng
中科院分区：
文献类型：
--
作者：
Mehran M. Izad;C. Heng
基于次谐波注入锁定振荡器的频率合成器可以有效地降低功率和面积。然而，它们受到注入脉冲中不希望看到的谐波引起的不想要的边带的影响。本文提出了一种脉冲整形技术，它可以减少注入脉冲中的这些不需要的谐波，并产生低杂散的合成输出。文中还深入讨论了该方法的稳健性和电路非理想性的影响。为了验证该技术的有效性，采用0.13-μMOS工艺制作了一款针对WiMedia UWB第一频段的测试芯片。实验结果表明，所提出的脉冲整形方法可使杂散衰减22dBc，并可将杂散抑制在-47dBc以下。该样机在4.488 GHz频率下实现了开关时间小于4.7 ns，相位噪声为-122dBc/Hz，频率偏移为1 MHz。该芯片的有源面积为0.15 mm2，在1.2V电源电压下仅消耗18 mA电流。
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-μm 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 mm2 and draws only 18 mA from a 1.2-V supply.