Cselt-centro Studi E Laboratori Telecomunicazioni S.p.a.

Pirelli & C. S. P. A.

Telecom Italia Lab S.p.a.

Telecom Italia S.p.a.

Cselt- Centro Studi E Laboratori Telecommunicazioni Spa

Luciano Accatino

Giorgio Bertin

Vincenzo Boffa

Alfredo Ruscitto

Paolo Semenzato

Giuseppe Grassano

Bruno Piovano

Fabrizio Gatti

Mauro Mongiardo

A tunable delay line for radiofrequency or microwave frequency applications consists of at least one ridge waveguide in which the ridge is movable in the waveguide body so as to vary the width of an air gap defined between the longitudinal end surface of the ridge and a confronting member of the waveguide. The ridge is moved by an actuator external to the waveguide body.

Tunable waveguide delay line having a movable ridge for providing continuous delay

A planar filter has a planar resonator including a conductive region having smoothed contours and supporting a first resonating mode propagating along a first conductive path and a second resonating mode propagating along a second conductive path perpendicular to the first conductive path. The planar filter also has a conductor-free region made in the conductive region and having smoothed contours. The conductor-free region is disposed along a region axis forming an angle with respect to the first conductive path. The conductor-free region causes a perturbation of the symmetry of the planar resonator resulting in a frequency shift of the first and second resonating mode and their mutual coupling.

Dual mode filter based on smoothed contour resonators

The dielectric loaded cavity for high frequency filters consists of a metal container housing s dielectric block held in position by supporting plates, that also sustains coupling and tuning elements. This invention provides broadband filters, small in size and with low losses. Its high symmetry structure considerably reduces the energizing of spurious modes and furthermore facilitates the design using automatic calculation procedures, on the basis of accurate electromagnetic models.

Dielectric loaded cavity for high frequency filters

The waveguide polarizer is a device for microwave antenna systems consisting of a waveguide section, with circular cross-section, being equipped with two terminal flanges for connection to other circular guides. A certain number of elliptical irises are arranged inside at regular intervals, resting on parallel planes and all oriented in the same way, i.e. with their longer axes all belonging to the same axial plane.

Waveguide polarizer

A multi-mode, typically triple-mode, cavity (1), for waveguide band-pass filters is disclosed, which cavity requires no tuning or coupling screws and rounded. The cavity comprises a waveguide element such as an iris (IR1) or a waveguide segment (CR2) arranged in a generically eccentric position with respect to the general development of the cavity and in particular to the main axis (Z) of the same. The cavity may be used to make narrowband filters for satellite communications. A filter comprising cavities (1) of the type described can be designed entirely using an electronic computer and requires no calibration procedure.

Multi-mode cavity for waveguide filters

The cavity has at least one waveguide segment with elliptical cross section whose axes are arranged at a given inclination angle (.alpha.) with respect to the polarization of the incident TE field. Thus a dual-mode cavity is realized, with the ability to let resonate two transverse fields (TE) with polarization planes orthogonal to each other. By adding a waveguide element able to introduce a non-axial discontinuity, a triple-mode cavity is obtained, allowing for an additional longitudinal mode to resonate as well.

Multi-mode cavity for waveguide filters, including an elliptical

Dual-mode cavity of waveguide bandpass filters, which allow the realization of narrow-band filters with very limited transition band and extremely low losses, without tuning or coupling screws or smooth edges. The dual mode cavity is composed of three coaxial sections of waveguide arranged in cascade and provided with irises, of which the two end sections are suited to support two modes with orthogonal polarizations and the intermediate section, consisting of a rectangular waveguide, has its side tilted with respect to the plane on which the irises lie. The whole filter composed of these cavities can be entirely designed by means of a computer and requires no tuning operation.

Dual-mode cavity for waveguide bandpass filter

The cavity resonator is composed of a closed metallic body transversely subdivided into two parts, housing a small dielectric cylinder, which is held in coaxial position inside the cavity by two small quartz plates provided with a centering indentation. Holes are provided in the lateral surface for tuning screws and an access connector and coupling irises can be cut in the bases.

Dielectric-loaded cavity resonator

An integrated microwave oscillator as which the generated frequency is stabilized by a dielectric resonator with high quality factor and stability. The positive feedback is assured not only by the dielectric resonator coupled to a line connected to a terminal of the active device, but also by a microstrip resonator connected in parallel to a second line connected to a second terminal of the active device. The signal generated is extracted from the third terminal of the active device.

Integrated microwave oscillator with microstrip resonator frequency

A delay line for microwaves, whose transfer function is subject to phase variations with changes in ambient temperature, is connected in cascade with a transmission line whose phase varies in the opposite sense. The transmission line, which may be integrated with the associated delay line in a common microstrip structure, is of such length as to maintain the overall phase shift substantially constant within a certain temperature range.

Growing community of inventors

Turin, Italy

Luciano Accatino