Hussein Ezzeddine

Coupling topologies for realizing compact microwave diplexers with dual-mode cavities

In this work, two topologies for realizing compact microwave diplexers in dual-mode cavities are presented. The first topology is a classical one, where the common port is coupled to two resonators in separate paths. The second topology is original because of the excitation of a single resonator by the common port. The interest of the second topology is demonstrated on dual-mode cavity diplexers by eliminating spurious cross-polarized modes which appear when using a classical topology. The proposed topologies have been validated by the design of coupled dual-mode cavity diplexers for satellite applications.

Compact diplexers and triplexers implemented with dual-mode cavities

In this paper, the design of compact diplexers and triplexers with dual-mode cavities is presented. Such devices are composed of coupled resonators without additional waveguide element, leading to a more compact architecture. Two topologies of compact diplexers are implemented and compared to a standard manifold diplexer. A hardware prototype is fabricated and measured for experimental verification. A compact triplexer is finally introduced for extending the concept to more than three ports.

Design of a dual-bandpass filter with dispersive coupling

In this paper, we intend to design of a wide band dualband filter with dispersive couplings for improved selectivity. The proposed approach consists to use this novel filter synthesis technique, taking advantage of the frequency variation of coupling values, for generating additional transmission zeroes. The dispersive coupling behavior is demonstrated and employed to design a four pole filter with three transmission zeros. The design is validated by a prototype and a six-pole dual-band bandpass filter based on the same concept is proposed for 5G millimeter-wave bands.

A dual-mode high-Q tunable filter reconfigured by cavity rotation

This paper proposes a new solution for implementing high-quality-factor tunable filters, suitable for high-power handling. The dual-mode filter is realized with a cylindrical cavity, which comprises metallic lugs and is loaded by a dielectric element. The center frequency is tuned between two states, by adjusting mechanically the position of the lugs within the cavity. The lugs allow modifying the capacitive effect between the dielectric element and the cavity for adjusting the resonant frequency.

Optimized Synthesis of Self-Equalized Microwave Filters

In this paper, a new methodology for synthesizing self-equalized filters is introduced. The methodology consists of optimizing the polynomial transfer and reflection functions considering amplitude and phase constraints simultaneously. The algorithm gives access to a more general class of functions than generalized Chebyshev (also called quasi-elliptic) functions. Two self-equalized filters are designed using this new methodology, and their performances are compared to general Chebyshev filters in order to put into evidence the interest of the proposed optimization algorithm. The first design leads to reduced group-delay variations, and the second one leads to a simplification of the hardware, reducing the number of resonators.

Design of compact and innovative microwave filters and multiplexers for space applications

In this paper, an original self-equalized filter and a compact diplexer are presented. New methodologies for synthesizing and designing these devices are introduced. Implementation in dual-mode cavities is preferred since this technology offers compactness and good electrical specifications required for space applications.