Continuous terahertz wave generation based on photomixers coupled to Fibonacci fractal tree antennas H. Jafari 1 • H. Heidarzadeh 2 • G. Rostami 3 • M. Dolatyari 3 • A. Rostami 1,2,3 Received: 15 March 2016 / Accepted: 7 November 2016 Ó Springer Science+Business Media New York 2016 Abstract A comprehensive analysis and numerical simulation of continuous wave tera- hertz (THz) generation based on photomixing is performed in this paper. For numerical investigation, both semiconductor and electromagnetic equations are considered. The effects of photomixer parameters and geometry of the antenna on terahertz power gener- ation (photocurrent and radiated power) are investigated. In this work, for improving performance of the integrated antenna, the fractal tree antenna for two different geometries (the narrow and wide conﬁgurations) using the Fibonacci sequence is presented. We demonstrate that the fractal tree antenna with Fibonacci series arrangement in the both cases of narrow and wide conﬁgurations increases the THz radiation power more than twice in comparison to usual dipole antenna. Keywords Terahertz  Photomixer  Fibonacci fractal antenna  High radiation power  THz generation 1 Introduction Terahertz technology is emerging as an active branch of research in recent years due to its application in security (Federici et al. 2005; Woolard et al. 1999), biomedical and phar- maceutical applications (Pickwell and Wallace 2006; Shen 2011), spectroscopy and imaging (Jansen et al. 2010; Wang et al. 2003; Hu and Nuss 1995).Generation and detection of THz radiation have become increasingly important and popular in various & A. Rostami rostami@tabrizu.ac.ir 1 OIC Research Group, University of Tabriz, Tabriz 5166614761, Iran 2 Photonic and Nanocrystal Research Laboratory (PNRL), Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz 5166614761, Iran 3 SP-EPT Laboratories, ASEPE Company, Industrial Park of Advanced Technologies, Tabriz, Iran 123 Opt Quant Electron (2016)48:534 DOI 10.1007/s11082-016-0810-9