Chirping Techniques to Maximize the Power-Handling Capability of Harmonic Waveguide Low-Pass Filters

Abstract

A novel chirping technique is applied to the design of very high-power waveguide harmonic low-pass filters. The technique could be used, for instance, to avoid multipactor testing in multicarrier systems such as the output multiplexer of a communications satellite. The novel chirped filter shows low insertion loss, all-higher order mode suppression, and broad stopband rejection up to the third harmonic. The paper focuses on the maximization of the filter power-handling capability without affecting its excellent frequency behavior. Given a certain frequency response, the E-plane mechanical gap of the structure and the length (in the propagation direction) of the waveguide sections between its constituent bandstop elements can be considered to improve the high-power behavior. However, the power performance may be not sufficient yet in some applications if we wish, for instance, multipactor testing to be avoided. This becomes feasible by chirping the length (in the propagation direction) of the bandstop elements. An example for Ku band is discussed for relevant frequency specifications. An improvement from around 8 kW (non-chirped filter) to more than 100 kW (chirped filter) is obtained. As a reference, the equivalent waffle-iron filter can handle only 0.15 kW. Such highpower threshold levels have been never reported before for such kind of filters.

Porous Si-SiO2 based UV Microcavities

“…The same method could be applied to porous Si-SiO 2 structures in the UV range. Notably, one way to obtain a broader optical response from these kinds of photonic structures is using chirping techniques 52 .…”

High-Power Filter Design in Waveguide Technology: Future Generation of Waveguide Satellite Filters in Payloads Handling Increasing Bit Rates and Numbers of Channels

“…4, to ease the fabrication by CNC milling [26] - [29]. In fact, from the thorough analysis performed in [30], it can be concluded that, considering appropriate geometries of the bandstop step-shaped elements, it is possible to fabricate (by CNC milling) low-pass filters addressing a wide stop band and featuring in practice (almost) unlimited power handling constraints (and, consequently, no need for costly high-power testing!). As an example, a device designed for Ka-band multibeam satellite payloads is shown in Fig.…”

Rectangular Waveguide Filters With Meandered Topology

“…with Meandered Topology Although compact high-power LPFs have been obtained in [21]- [23] an E-plane bend cannot be embedded in these types of filters. Hence, if an E-plane bend is required before or after the LPF, two different structures will be needed (with their corresponding flanges, screws, etc.).…”