Rectangular waveguide fed DRA using tapered waveguide section

Abstract

for both TE and TM polarization provides very stable resonant frequency, that is, 8.8 GHz. For TE and TM mode of normal incidence, the results showed that measured 210 dB bandwidth for 90% power absorption and 220 dB bandwidth for 99% are 2.08 and 0.6 GHz at the resonant frequency, respectively. Additionally, the measured result shows good agreement with those of the simulated one. The results implicitly mean that the proposed design holds a highly stable frequency response for oblique angular incidence for both TE and TM modes of polarization. CONCLUSIONIn this letter, we proposed and fabricated the transparent EM absorber with frequency selective pattern as a circuit analogue, which has the frequency stability for different incidence angles and polarizations and wide absorption bandwidth. Simulation was performed using commercial EM software to obtain the reflection loss of the structure and then the measurement results of the fabricated one were compared. It was observed that the design provides stable absorbing characteristics for polarization and different angles of incidence as well as wide absorption bandwidth as expected. REFERENCES

Analysis and experiment of stair‐shaped waveguide‐fed dielectric resonator antenna

“…This is due to the very small surface roughness of the DRA and ground plane that leads to uneven air gaps between the ground plane and DRA. The thin air gap introduced between the ground plane and DRA lowers the equivalent permittivity of the DRA, which leads to the increase in resonant frequency [28, 29]. The shift in resonant frequency can be reduced by making the ground plane and bottom surface of the DRA flat and smooth by using better fabrication techniques.…”

Dual-Band Waveguide Fed Hollow Cylindrical Dielectric Resonator Antenna

“…In this structure, the number of DRAs increases the cost as well as the fabrication difficulty. Different coupling enhancement techniques for waveguide-fed DRAs are achieved by a stair-shaped waveguide [16], tapered waveguide [17], and capacitive waveguide junction [8]. All these structures are of single-band operation and suffer from fabrication intricacy.…”

Microwave Doppler velocity measurement using tapered rectangular waveguide antenna with pattern offset correction

“…Antenna is an important device in wireless communication and radar systems . With the advantages of compact structure, high directivity, high radiation efficiency, and reliability, rectangular waveguide antenna is often used as a front‐end in industrial measurement such as the velocity measurement of moving gas‐solid flows in pipes …”