Peak Power Handling Capability in Groove Gap Waveguide Filters Based on Horizontally Polarized Resonators and Enhancement Solutions

Abstract

This letter studies the peak power handling capability (PPHC) in groove gap waveguide filters based on horizontally polarized resonators. Moreover, a modification of the resonant cavity is proposed, where the central pins of the original structure are replaced by a rounded metal block. As a result of this change, the TE 101 -like mode can still be excited, but the maximum electric field strength is shifted to the center of the cavity, which leads to a higher PPHC. The main advantages of the original structure are maintained, and greater robustness in the manufacturing process is achieved. Next, some guidelines for the design of the coupling windows and the dimensions of the blocks are shown to minimize the electric field strength and, consequently, maximize the PPHC. Finally, two third-order bandpass filters (with pins and with blocks) centered at 16 GHz have been manufactured and tested in a measurement campaign, where a PPHC enhancement of 8.7 dB at high pressures is achieved for the novel solution presented in this work.

Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with 3D Printing and CNC Milling Techniques

“…Table 5 compares various GGW bandpass filters with the wideband GGW Chebyshev filters manufactured in this work. The order n or number of cells of the GGW filters [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] reported in Table 5 varies between two and seven, and almost half of them are of order five, as are the proposed GGW filters. The structures were mainly manufactured by means of a CNC milling machine, except for two [36,41] that also used a 3D printing technique.…”

“…Half of them are distributed in the low X and Ku bands (8 GHz-18 GHz) as the proposed design. As can be seen in Table 5, unlike the proposed design method and [45], which can achieve wideband responses (FBW > 10%), the other filters developed are narrowband (FBW < 4%), since they were obtained from resonant cavities [30][31][32][33][34][35][36], coupled resonators [37][38][39][40][41][42], evanescent wave coupled resonators [43], and periodic corrugations acting as resonators [44], which can only work in a narrow bandwidth. The wideband response of the proposed GGW bandpass filter design was obtained by combining the high-pass behavior of the GGW with the low-pass characteristic of the metallic pins placed along the groove area of the GGW, acting as impedance inverters.…”

“…Several bandpass filters have been successfully implemented in GGW technology [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. Their designs are based on resonant cavities [30][31][32][33][34][35][36], coupled resonators [37][38][39][40][41][42], evanescent wave coupled resonators [43] and periodic corrugations acting as resonators [44]. Due to their configurations, these bandpass filters are narrowband type.…”

In-Depth Study of the Corona Discharge Breakdown Thresholds in Groove Gap Waveguides and Enhancement Strategies for Inductive Bandpass Filters

“…With respect to previous research related to the corona discharge breakdown thresholds in GW technology, a preliminary study based on simulations for guided structures can be found in [42], where measured results are not presented. Moreover, a strategy for enhancing the PPHC in horizontally polarized BPFs has been proposed in [43], where a measured improvement of 8.7 dB in the high-pressure range has been demonstrated. Also, other recent trends can be highlighted in the area of the corona discharge breakdown in microwaves, such as those where some novel numerical approaches have been studied [44], [45].…”