[1] [1] Essen H, Stanko S, Sommer R, et al. A high perfmance 220GHz broadb experimental radar[C]International Conference on Infrared IEEE, 2008.

[2] D Krista, K Tero, M Juha, et al. Mixer-based characterization of millimeter-wave and terahertz single-anode and antiparallel Schottky diodes. IEEE Transactions on Terahertz Science and Technology, 4, 552-559(2014).

[3] K B Cooper, R J Dengler, N Lombart, et al. Penetrating 3-D imaging at 4- and 25-m range using a submillimeter-wave radar. IEEE Transactions on Microwave Theory and Techniques, 56, 2771-2778(2008).

[4] Y Zhang, W Zhao, Y F Wang. A 220 GHz subharmonic mixer based on schottky diodes with an accurate terahertz diode model. Microwave & Optical Technology Letters, 58, 2311-2316(2016).

[5] L H Jiang, W S Wang, H X Tong, et al. Reaserch progress of terahertz imaging in the field of human security. University of Shanghai for Science and Technology, 41, 46-51(2019).

[6] E R Carlson, M V Schnider. Sub-harmonically pumped millimeter wave mixers. IEEE Transactions on Microwave Theory and Techniques, 26, 706-715(1978).

[7] S Marvin, B Alderman. Design of low-cost 183 GHz subharmonic mixer using planer schottky diodes. IEEE Microw Wirel Compon Lett, 15, 865-867(2005).

[8] W C Min, H Sun, Q L Zhang, et al. A high-performance W-band subharmonic mixer based on anti-parallel diode pair. Chinese Journal of Electron Device, 39, 1283-1286(2016).

[9] Ge Liu, Bo Zhang, Lisen Zhang, et al. 0.42 THz subharmonic mixer based on 3D precisely modeled diode. Journal of Infrared and Millimeter Waves, 37, 338-343(2018).

[10] B Zhang, G Liu, X F Yang, et al. Research on the front-end of 380 GHz radiometer. Journal of Microwaves, 31, 26-29(2015).

[11] X Y Zhao, J L Wang, D B Xing, et al. Parameters model of terahertz planar Schottky diode. Infrared and Laser Engineering, 45, 1225004(2016).

[12] Y He, K Huang, L Miao, et al. Design of 250 GHz terahertz sub-harmonic mixer. Journal of Microwaves, S1, 69-72(2015).

[13] [13] Hu H F, Ma X M, Jiang S L, et al. Schottky diode based 220 GHz receivers operating at roomtemperature f passive security scanning[C]44 International Conference on Infrared, Millimeter, Terahertz Waves, 2019.