Design Of The Wideband Antennas For THz Source Based On The Uni-travelling-carrier Photo-diode

Terahertz wave is between millimeter wave and infrared in electromagnetic spectrum,hence there are two kinds of research methodologies for Terahertz wave:electronics and photonics. The photon energy of terahertz wave is very low and has little damage to biological creatures. It is widely used in medical detection and security and so on. Besides, because of its high frequency, the terahertz wave can be used as carrier wave to achieve high bits rate in wireless communications. The study on terahertz technique can fuel the development of science and make a better world.There are many countries and scientific research institution have done numerous deep research in this field in the recent years. In this thesis, we focused on the design of a THz broadband integrated lens antenna which integrates the uni-travelling-carrier photo-diode to the lens. This terahertz source is compact and low cost, more importly,can be able to work in room temperature.The bow-tie planar antenna has advantages such as easy to manufacture, can be integrated with other devices, be able to have impedance tuning and broadband, so it is a suitable candidate for terahertz source. However, owing to the high frequency of terahertz wave, terahertz antenna placed on the dielectric material can result in surface wave effect and low gain of radiation. To solve this problem, we use a dielectric lenses. The lens can also collimate the rays and improve the directivity and radiation pattern. The integrated hemispherical lens behaves better in manufacture and its performance satisfied the demand. After simulate the bowtie antenna and extended hemisphere lens in CST electromagnetic software, we have the optimized physical parameter: the length of bow tie is 160?m and the width is 320 ?m, the radius of lens is 3000 ?m achieving the antenna gain with 25.5dB.There are two kinds of antenna arrays. One is connected array in E plane whose unit's arm lengh is 80?m. It fixs the problem of the appearance of grating lobes and has the peak gain of 18.2dB. Another one is array in H plane which is placed on the extended hemisphere lens, when the distance between the units is 200 ?m, the width of bowtie is 160 ?m ,the array can provide the peak gain up to 21.4 dB, with the beamwidth of 15.5°.