Articles | Volume 3
Adv. Radio Sci., 3, 143–146, 2005
https://doi.org/10.5194/ars-3-143-2005
Adv. Radio Sci., 3, 143–146, 2005
https://doi.org/10.5194/ars-3-143-2005

  12 May 2005

12 May 2005

Radiation Efficient Unidirectional Low-Profile Slot Antenna Elements for X-Band Application

C. Löcker, T. Vaupel, and T. F. Eibert C. Löcker et al.
  • FGAN-Research Institute for High Frequency Physics and Radar Techniques (FHR), Neuenahrer Str. 20, 53343 Wachtberg-Werthhoven, Germany

Abstract. Slots in metallic ground planes are very promising candidates for conformal antenna applications. However, a low-profile unidirectional antenna requires a back reflector close to the slot and the resulting stripline feed causes strong excitation of parallel-plate modes. In this contribution, we consider unidirectional reflector-backed slot configurations with parallel-plate mode suppression by shorting pins. Starting from a parametric study with respect to shorting pin location and back reflector distance, we present a stripline-fed rectangular slot element with radiation efficiency of more than 80% and a bandwidth of about 5% at centre frequency 10GHz. A careful optimisation of shorting pin locations guarantees reliable parallel-plate mode suppression without deteriorating the slot radiation behaviour. Coupling coefficients between parallel and aligned rectangular slot elements are presented. For increased bandwidth applications, a bow-tie slot element with about 8% bandwidth and radiation efficiency of close to 80% is proposed.