Broadband Oscillator-Free THz Pulse Generation and Radiation Based on Direct Digital-to-Impulse Architecture
Broadband Oscillator-Free THz Pulse Generation and Radiation Based on Direct Digital-to-Impulse Architecture
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DOI：
10.1109/jssc.2017.2739180
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发表时间：
2017-11-01
影响因子：
5.4
通讯作者：
Babakhani, Aydin
中科院分区：
文献类型：
--
作者：
Assefzadeh, M. Mahdi;Babakhani, Aydin
宽带0.03-1.1太赫兹信号的产生和辐射基于无振荡器直接数字-脉冲结构，半高全宽为1.9-ps，中心频率为160 GHz的130-GHz 3-d B带宽(200-GHz 10-d B B W)。得到的峰值脉冲有效各向同性辐射功率为19.2dBm，峰值脉冲辐射功率为2.6 mW。引入并实现了一种开/关脉冲整形技术，以抑制不需要的振铃并提高DC-辐射效率。测得重复率为5.2 GHz的脉冲串的频率梳状谱高达1.1太赫兹。在距离4 cm处，在1和1.1THz处测得的接收信噪比分别为28和22分贝。测量了一个1.1太赫兹的音调，10分贝的频谱宽度为2赫兹，显示出极窄的谱线宽度(万亿分之二)。使用定制的基于飞秒激光的太赫兹时间域光谱分析系统来表征时间域皮秒脉冲。演示了由两个间隔较大的码片进行相干空间合成。结果表明，辐射脉冲的起始时间被锁定在输入数字触发器的边缘，定时抖动为270ps。该芯片采用130 nm SiGe BiCMOS工艺制造。
Broadband 0.03-1.1 THz signal generation and radiation are demonstrated based on an oscillator-free direct digital-to-impulse architecture with a 1.9-ps full width at half maximum and 130-GHz 3-dB bandwidth (BW) (200-GHz 10-dB BW) centered at 160 GHz. The radiated pulse achieves a peak pulse effective isotropic-radiated power of 19.2 dBm and peak pulse-radiated power of 2.6 mW. An ON/OFF impulse-shaping technique is introduced and implemented to suppress undesired ringing and to increase dc-to-radiated efficiency. The frequency-comb spectrum of the radiated pulse train with 5.2-GHz repetition rate is measured up to 1.1 THz. At a distance of 4 cm, the measured received SNR at 1 and 1.1 THz is 28 and 22 dB, respectively. A 1.1-THz tone is measured with a 10-dB spectral width of 2 Hz, demonstrating an extremely narrow spectral line width (two parts per trillion). Time-domain picosecond pulses are characterized using a custom femtosecond-laser-based terahertz time-domain spectroscopy system. Coherent spatial combining from two widely spaced chips is demonstrated. It is shown that the starting time of the radiated pulses is locked to the edge of the input digital trigger with a timing jitter of 270 fs. The chip is fabricated in a 130-nm SiGe BiCMOS process technology.