Mm-wave Wideband Dual-Polarized High Suppression Filtenna on LTCC

This paper presents a mm-wave wideband dual-polarized high suppression filtenna on LTCC. Placed on two different substrates, the proposed filtenna is composed of three kinds of patches: driven patches and parasitic patches on the bottom substrate and on the top substrate. The driven patches are fed by four ideal differential ports at the end. Four shorting pins are loaded on the driven patches, respectively. With the shorting pins and specific dimensions, the driven patches can radiate under two modes for wideband. Meanwhile, a radiation null is obtained in low band. The parasitic patches can improve bandwidth and generates the other two radiation nulls in high band. Thus, the proposed filtenna features high out-of-band suppression. The -10dB impedance bandwidth of the proposed filtenna is of 25%, covering from 23GHz to 29.6GHz. The proposed filtenna performs low band and high band suppression greater than 33.5 dB and 27.2 dB, respectively.

I. Introduction

Broad bandwidth dual-polarized antennas have grown in popularity recently with the rapid development of fifth-generation (5G) communication in mm-wave frequencies. In order to achieve more stable performance, higher demands are placed on the antenna size. Low temperature ceramic con-fired (LTCC) technology features compact size due to high integration in three dimension, making it a suitable candidate for mm-wave package application [1]. However, the antenna bandwidth are limited because the high dielectric constant of LTCC [2–3]. Therefore, it is necessary to design a wideband antenna on LTCC. The mm-wave spectrum includes the 24/28GHz in the Ka-band, which it is near to the satellite communication band. Strong interference may exist between the two bands, thus degrading the communication quality. Filtennas could be a valuable candidate to reduce out-of-band interference with high in-band efficiency in mm-wave [4]. In this paper, a wideband dual-polarized filtenna with high suppression on LTCC is presented. The -10dB impedance bandwidth of the proposed filtenna is of 25%, covering from 23GHz to 29.6GHz. The proposed filtenna performs low band and high band suppression greater than 33.5 dB and 27.2 dB, respectively. The antenna configuration, working mechanism and results are presented as follows.