Monolithic integrated ceramic waveguide filters

Abstract

-Design techniques for a new class of integrated monolithic high permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled TEM filters with the same unloaded Q-Factor. Designs for both chebyshev and asymmetric generalized chebyshev filter are presented, with experimental results for an 1800 MHz chebyshev filter showing excellent agreement with theory.

Monolithic ceramic waveguide filter with wide spurious free bandwidth

“…Fig 2 shows a physical layout of NWCW filter. A comparison of simulated results of a NWCW filter with that of integrated ceramic waveguide filter [5] is shown in fig 3. EM simulated results show that a NWCW filter offers significantly improvement (up to 60%) in the stop band performance of a ceramic waveguide filter.…”

“…Ceramic waveguide filters offer miniaturization by using high Permittivity materials [3,4], but their crowded higher order resonances limit spurious free out of band spectrum. A ceramic filled waveguide filter achieves 50% size reduction as compared to coaxial TEM filter but their spurious free out of band rejection is limited to higher order waveguide modes [5]. Different design techniques have been proposed for the improvement of spurious performance of waveguide filters.…”

Mixed non-uniform width/evanescent mode ceramic resonator waveguide filter with wide spurious free bandwidth

“…The couplings are achieved as described in [3]. The filter provides the 40 dB stop band attenuation up to 3.60 GHz which is about 75 % improvement in spurious performance compared to the uniform width integrated ceramic waveguide filter [2]. Fig 2. Show the physical layout of the proposed ceramic waveguide filter1.…”

“…Dielectric TEM filters offer a very good spurious performance but a high volume; whereas ceramic filled waveguide filters provide 50% miniaturization but have crowded modes in proximity with the pass band [1,2]. Many techniques have been used to improve the stop band performance of waveguide filters.…”

“…Recently, different irises were proposed with Non-uniform widths in rectangular waveguide filter to increase the stopband region [9]. In Ceramic waveguide filter, Step impedance resonators, nonuniform width (NW) resonators and evanescent mode nonuniform width (NW) resonators were used to improve the spurious performance [2,10]. This paper presents a new design approach to combine nonuniform width ceramic waveguide resonators with ceramic evanescent mode resonators to notably increase the spurious free region with small degradation of overall Q-factor of the Ceramic Waveguide filter.…”