Dielectric Antenna Adds Photomixer for Terahertz Emissions
The use of terahertz EM energy in combination with optoelectronics technology offers great promise for short-range, high-data-rate communications, which will likely be needed in Fifth-Generation (5G) wireless-communications networks and to appease the general public’s growing obsession with having more data available on mobile wireless devices. To facilitate such communications, photomixing has been performed to achieve carrier waves at terahertz frequencies. Accordingly, researchers from sites in Spain, Finland, and Germany have developed a dielectric rod waveguide (DRW) antenna with integrated photomixer.
Classic generation of terahertz signals involves the photomixing of two heterodyne laser beams in a semiconductor device with signals emitted by a suitable antenna for the wavelength of interest. Since power from available semiconductor devices is quite limited at terahertz frequencies, the design of the antenna is critical for achieving a usable radiation pattern.
The researchers chose to integrate the photomixer with a planar DRW antenna for its low cost and ease of fabrication on commonly available substrate materials, such as silicon or GaAs semiconductor wafers. A prototype was manufactured on 500-μm-thick GaAs; the antenna has a cross section of 1.0 × 0.5 mm2. It can be fed by rectangular metal waveguide for ease of installation, and produced consistent radiation patterns at 137 GHz.
See: “Dielectric Rod Waveguide Antenna as THz Emitter for Photomixing Devices,” IEEE Transactions on Antennas and Propagation, Vol. 63, No. 3, March 2015, p. 882.