Co‐designed substrate‐integrated waveguide filters with patch antennas

Abstract

A new approach to integrate high‐quality (Q)‐factor three‐dimensional vertical cavity filters with patch antennas into a single unit is presented. This integrated filter/antenna system exhibits small footprint, high efficiency and enhanced bandwidth. The patch antenna is designed to provide an additional transmission pole for the filtering function and works as a highly efficient radiator. In addition, this integrated patch antenna with a filter can achieve a bandwidth larger than that of a standalone patch antenna with the same geometry. A prototype three‐pole Chebyshev filter/antenna is demonstrated at X band. The centre frequency and fractional bandwidth of the filter/antenna system are 10.27 GHz and 8.7%, respectively. Owing to the high Q factor ( ∼650) of the cavity resonator and near loss‐less transition between the antenna and filter, the overall efficiency of the filter/antenna system is simulated to be as high as 91.8%. The reduced footprint, enhanced bandwidth and low‐loss performance of these integrated filter/antenna systems make them particularly useful for phased array applications. Prototypes of the filter/antenna systems as well as a filter/antenna array are fabricated and measured. An excellent agreement between the simulated and measured results is observed.

Evanescent-mode-resonator-based and antenna-integrated wireless passive pressure sensors for harsh-environment applications

“…The patch antenna is located on the top surface of the sensor cap and coupled to the pressure sensor though a rectangular slot etched inside the ground plane on the bottom of the sensor cap. Similar to the filter/antenna integration technique presented in [27], this integrated patch antenna occupies zero additional volume and exhibits close to 100% antenna efficiency. The patch antenna is designed using the dielectric properties measured in Section 2.…”

An Integrated Filtering Antenna Array With High Selectivity and Harmonics Suppression

“…In [8], novel multiplexers were demonstrated based on all-resonator structures, eliminating the conventional transmission-line based signal distribution networks. The integration of filters and antennas has attracted significant research interests during the past several years [9]- [22]. By virtue of their resonant nature, some antennas can serve as the last resonators of the filters.…”

Integrated single-fed circularly-polarized patch antennas with high-Q cavity filters

“…By co-designing the filter with the antenna, traditional 50-ohm ports between filters and antennas are removed, which not only eliminates the transition loss but also shrinks the size. In addition, linearly polarized (LP) antennas such as slot antennas [3], [4], and patch antennas [5], have been vertically integrated with 3-D cavity filters to further reduce the footprint for antenna array applications. However, for applications such as satellite communication systems, Global Positions Systems (GPS), and Wireless Area Local Networks (WLAN), CP antennas have wider uses than LP antennas because of the additional freedom in the orientation angles between the receivers and transmitters.…”

“…The two-pole cavity filter and the CP patch antenna are codesigned based on the integrated filter/antenna technique [5]. The design parameters of the filter/CP antenna are the external quality factors of the first cavity resonator Q ext1 , the external quality factors of the patch antenna Q ext2 , the internal coupling coefficient k 12 and the resonant frequency f 0 .…”