Front-to-back ratio

About: Front-to-back ratio is a research topic. Over the lifetime, 292 publications have been published within this topic receiving 3314 citations.

Low sectional plane printing element antenna unit

Abstract: The utility model relates to a low-profile printed dipole antenna, which comprises radiating units (1), a micro-band feeder panel (2), a metal bottom plate (3) and a matching medium block (4). The low-profile printed dipole antenna is characterized in that the dipole antenna is printed on the micro-band feeder panel (2), two radiating units (1) are simultaneously riveted at the upper end of the micro-band feeder panel (2), the lower end of the micro-band feeder panel (2) is fixedly connected with the metal bottom plate (3), a through hole is arranged on the metal bottom plate (3), a feeder line is threaded through the through hole to be connected with a feeding point, and the matching medium block (4) used for the matching adjustment is overlapped on the two radiating units. The overall structure of the low-profile printed dipole antenna is very simple, the aspects such as processing and assembling consistency, etc. are easy to guarantee, the realizability of the mass production is strong, the indexes of the front to back ratio of an antenna unit and the front to back ratio of an antenna array are improved greatly, the beam width consistency of the unit is improved, the forceful support to the arithmetic research of the system is improved, and simultaneously the index of the separation degree between adjacent antenna arrays is greatly improved.

Novel Design of Cavity-Backed Slot Antenna by Reformed Ground Plane (Corner Notch and Stepped) and Elongated Mushroom (EM)-EBG

Abstract: A common problem for the performance of a Cavity-Backed Slot (CBS) antenna could be the heavily effect of ground plane. Travelling surface currents on ground plane could cause destructive effect on the characteristics of CBS antenna. This mainly appears on gain back lobe and also Front to Back Ratio (FBR) of pattern. To resolve this problem, the stepped ground plane and the Extended Mushroom Electromagnetic Band-Gap (EM-EBG) structure was introduced, which could minimize ground plane effects by changing the current distribution. Good agreement was achieved between the simulated and measured results. Experimental results showed that on a frequency range over 14-16 GHz, the gain was better than 11 dB and FBR of pattern in the H-plane reached to 26 dB.

An extraordinary transmission analogue for enhancing microwave antenna performance

Abstract: The theory of diffraction limit proposed by H.A Bethe limits the total power transfer through a subwavelength hole. Researchers all over the world have gone through different techniques for boosting the transmission through subwavelength holes resulting in the Extraordinary Transmission (EOT) behavior. We examine computationally and experimentally the concept of EOT nature in the microwave range for enhancing radiation performance of a stacked dipole antenna working in the S band. It is shown that the front to back ratio of the antenna is considerably enhanced without affecting the impedance matching performance of the design. The computational analysis based on Finite Difference Time Domain (FDTD) method reveals that the excitation of Fabry-Perot resonant modes on the slots is responsible for performance enhancement.

Very broadband feed for paraboloidal reflectors

Abstract: A compact, very broadband, linearly polarized feed unit has been developed for use in large aperture paraboloidal reflectors. The unit, a multi-dipole array provides 4 separate feeds covering 4 adjacent 2:1 bands with good front to back ratio and VSWR. On three of the bands front to back ratio is generally 10 db and of ten 15 db or better. Front to back ratio on the lowest band is better than 8 db. Model tests of the feed plus reflector indicate that secondary pattern beamwidths and side lobes are good over the band with side lobes between 20 to 30 db down in the E plane and below 10 db in the H plane. Directivity as calculated from beamwidths closely corresponds to theoretical directivity over the whole band. Compact mechanical packaging is achieved in balun construction.