0.14THz高功率太赫兹脉冲的频率测量

Frequency measurement of 0.14 THz high-power terahertz pulse

提出了采用截止波导法与谐波混频法相结合的方式,进行0.14THz高功率短脉冲的频率测量.首先将两个截止频率分别为0.125和0.15THz的非标准矩形波导作为接收端,通过截止波导滤波法获得了太赫兹辐射源的频率范围.然后根据已知的频率范围,将本振频率选择为15—20GHz,则谐波混频的谐波次数确定为8.随后的Ka波段的脉冲测试和0.14THz连续波测试表明,该8次谐波混频器可用于0.14THz脉冲的混频测量.最后,0.14THz脉冲频率测量实验给出了太赫兹辐射源的准确频率为0.1465THz.该方法大大降低了对本振信号的频率要求,且结果准确可信,为长波段太赫兹脉冲的频率测量提供了一种新的思路.

The subharmonic heterodyne combined with cut-off waveguide method is proposed to measure the frequency of 0.14 THz high-power nanosecond pulse in this paper.Using the cut-off waveguide method,the frequency range of the terahertz pulse is determined,in which two non-standard rectangular waveguides with cut-off frequencies of 0.125 and 0.15 THz are separately used as a receiver.According to the preliminary result,the subharmonic order is chosen to be 8,while the frequency of local oscillator is set to be in a range of 15—20 GHz.A series of tests on the 8th harmonic mixer is done using the pulses in Ka-band and the 0.14 THz continuous wave source,separately.Experimental results indicate that the mixer can be used in the heterodyne measurement of 0.14 THz nanosecond pulse.Finally,the heterodyne measurement is carried out on the high-power terahertz puls source,and an accurate frequency of 0.1465 THz is determined in this experiment.This novel method,which greatly reduces the frequency requirement of the local oscillator,is proved to have a good performance in the frequency measurement of 0.14 THz nanosecond pulse,and probably provides a new idea for frequency measurement of pulses in the long-wavelength terahertz-band.