DBI (Human) ELISA Kit

This letter presents a microstrip patch antenna array fed with a low-loss and highly efficient feeding structure called empty substrate-integrated waveguide (ESIW). The proposed antenna array targets 5G wireless communication systems operating at 28 GHz. The antenna array consists of 4 x 4 radiating patches, where every four radiating elements are grouped together forming a 2 x 2 subarray and each of the subarrays is fed by ESIW feeding network by aperture coupling. The experimental results demonstrate good agreement with the simulated results, offering a wide |S-11| < -10 dB bandwidth of 12.4%, i.e., 26.5-30 GHz. A peak gain of 18.2 dBi and a high efficiency of about 91% are achieved using the proposed structure. Furthermore, the low-profile substrate of the ESIW feeding structure makes seamless integration of the proposed antenna array with the millimeter-wave front end. The advantages, such as low fabrication cost and high efficiency, make the proposed antenna array a suitable solution for millimeter-wave 5G wireless communication systems.

This article proposes a synthesis method based on phase modulation to design broadband oversized smooth-walled horns for high-power millimeter-wave applications. The bandwidth of oversized smooth-walled horn is confined by the mismatch of the relative phase between TE11 mode and TM11 mode. By analyzing the mode conversion along horn, it is found that the phase of the generated TM11 mode can be influenced by the TE11 mode. Therefore, the synthesis method uses a slow waveguide taper, in which the generated TM11 mode is in a small fraction and its phase is efficiently influenced by TE11 mode, to modulate the relative phase of TE11 mode and TM11 mode. Using the proposed method, an oversized smooth-walled horn is designed, of which the phase mismatch is +/- 10 degrees in the range of 32-38 GHz. The simulation results show that the proposed horn has a highly symmetric far-field pattern with a peak gain greater than 28 dBi in the range of 32-38 GHz and the sidelobe level has -19 dB decline compared with the peak gain. A prototype is fabricated and the near-field pattern measurement is carried out. The high correspondence of the simulated near-field patterns with the measured ones proves that the proposed method is an appropriate option to design broadband feed horns for high-power millimeter wave.