Distinct Gaussian Properties of Multiple Reflections in Extended Hemispherical Lenses

Ozbey B., Sertel K.

JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES, cilt.40, sa.11-12, ss.1053-1073, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 40 Sayı: 11-12
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1007/s10762-019-00632-x
  • Dergi Adı: JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1053-1073
  • Anahtar Kelimeler: Lens-integrated antenna, Double-slot antenna, Extended hemispherical lens, THz time domain spectroscopy (THz-TDS), Ray tracing, ANTENNAS, SILICON, PERFORMANCE, RECEIVER, DESIGN
  • Ankara Üniversitesi Adresli: Hayır

Özet

Multiple reflections in an extended hemispherical lens are shown to exhibit distinctly different Gaussian characters. It is demonstrated that the second- and third-order bounces of the electromagnetic fields within the electrically large lens result in contributions with spot sizes and locations that are uncorrelated with the fundamental Gaussian-beam-like radiation from a small antenna located at the lens focus. We present the optical properties (Gaussicities and power levels at the beam waist) of such higher-order lens reflections. The impacts of these reflections on a typical quasi-optical spectroscopy setup are discussed. The relative received power densities are computed and compared with measurements for each higher-order reflection. The agreement between the measurement and theory indicates that the adopted method is a reliable and efficient tool for characterization of the dominant reflections from extended hemispherical lenses.