We propose a broadband end-fire antenna for continuous-wave terahertz (THz) photomixing–based devices working in the frequency range of 0.5–1 THz. A compact Vivaldi antenna is presented that does not require any hyper-hemispherical silicon lens to collect and collimate THz radiation unlike the conventionally used broadside antennas. The antenna is tailored to radiate THz into or receive radiation from a dielectric waveguide placed in close vicinity of it. The antenna is fabricated on an indium phosphide (InP) substrate. A silicon (Si) superstrate is used to improve the directionality of the radiated beam. THz power coupled into Si waveguides is measured using two different techniques between 0.1 and 1.15 THz. Firstly, the waveguide is placed in the optical path of a 1550 nm based continuous-wave THz setup with a commercial broadside emitter, focusing optics, and a detector fabricated on the InP substrate with log-periodic broadside antenna. Secondly, the waveguide is placed in direct contact with the designed Vivaldi antenna–based THz receiver and using the commercial broadside emitter as a source. It is observed that the direct coupling technique using the Vivaldi end-fire antenna outperforms the optically coupled approach at frequencies higher than 668 GHz. Efficient THz photoconductive sources and receivers based on the designed compact Vivaldi end-fire antenna will be suitable for launching THz power into on-chip THz circuitry and for compact THz systems.

中文翻译：

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用于太赫兹混频器的维瓦尔第端射天线

我们为在0.5–1 THz频率范围内工作的基于连续波太赫兹（THz）光混合的设备提出了宽带端射天线。提出了一种紧凑的维瓦尔第天线，与常规使用的宽边天线不同，该天线不需要任何超半球形硅透镜来收集和准直THz辐射。天线经过专门设计，可将THz辐射到位于其附近的介质波导中或从中接收辐射。天线在磷化铟（InP）基板上制造。硅（Si）覆盖层用于改善辐射束的方向性。使用介于0.1和1.15 THz之间的两种不同技术来测量耦合到Si波导中的THz功率。首先，将波导放置在具有商用宽边发射器的基于1550 nm连续波THz设置的光路中，聚焦光学器件以及在对数周期宽边天线的InP基板上制造的检测器。其次，将波导放置在与设计的基于维瓦尔第天线的太赫兹接收器直接接触的位置，并使用商用宽边发射器作为源。可以看出，在高于668 GHz的频率下，使用维瓦尔第端射天线的直接耦合技术要优于光耦合方法。基于设计紧凑的维瓦尔第端射天线的高效太赫兹光电导源和接收器将适用于将太赫兹功率发射到片上太赫兹电路以及紧凑太赫兹系统。波导放置在与设计的基于Vivaldi天线的太赫兹接收器直接接触的位置，并使用商用宽边发射器作为源。可以看出，在高于668 GHz的频率下，使用维瓦尔第端射天线的直接耦合技术要优于光耦合方法。基于设计紧凑的维瓦尔第端射天线的高效太赫兹光电导源和接收器将适用于将太赫兹功率发射到片上太赫兹电路以及紧凑太赫兹系统。波导放置在与设计的基于Vivaldi天线的太赫兹接收器直接接触的位置，并使用商用宽边发射器作为源。可以看出，在高于668 GHz的频率下，使用维瓦尔第端射天线的直接耦合技术要优于光耦合方法。基于设计紧凑的维瓦尔第端射天线的高效太赫兹光电导源和接收器将适合于将太赫兹功率发射到片上太赫兹电路以及紧凑太赫兹系统中。