A microwave structure having an input section for receiving both a common mode signal and a CPW differential mode signal; an output section; and a CPW transmission line, having a center conductor disposed between a pair of coplanar ground plane conductors, connected between the input section and the output section. The conductors of the CPW transmission line are configured to provide the common mode signal a different attenuation in passing to the output section than the CPW transmission line provides to the differential mode signal passing between the input section and the output section.

A microwave structure having an input section for receiving both a common mode signal and a CPW differential mode signal; an output section; and a CPW transmission line, having a center conductor disposed between a pair of coplanar ground plane conductors, connected between the input section and the output section. The conductors of the CPW transmission line are configured to provide the common mode signal a different attenuation in passing to the output section than the CPW transmission line provides to the differential mode signal passing between the input section and the output section.

Systems and methods for mode suppression in a cavity are provided. In certain implementations, an apparatus comprises a cavity for propagating electromagnetic signals therein, wherein the electromagnetic signals propagate multiple times through the cavity; and an absorbing material applied to a first side of the cavity, wherein the absorbing material absorbs the electromagnetic signals. Further, an apparatus includes at least one transmitting antenna configured to couple electromagnetic energy into the cavity; and at least one receiving antenna configured to couple electromagnetic energy from the cavity.

A signal transmission line or an electrical connector includes an inner electrical conductor, an outer electrical conductor, a dielectric region between the inner electrical conductor and the outer electrical conductor, and an electrically thin resistive layer within the dielectric region and concentric with the inner electrical conductor and the outer electrical conductor. The electrically thin resistive layer is a resistive layer configured to be transparent to a substantially transverse-electromagnetic (TEM) mode of transmission, while absorbing higher order modes of transmission.

It is disclosed a waveguide array antenna for satellite communications. The antenna is configured to transmit and/or receive a first polarization signal and a second polarization signal, the second polarization being orthogonal to the first polarization, and comprises an array of unit cells, each comprising a radiating element. The antenna comprises: a grid configured to divide each radiating element into sub-elements having an inter-element distance lower than or equal to the wavelength at a highest frequency of operation of the antenna; and an electromagnetic band gap layer configured to support the grid above the radiating elements. The grid comprises a number of grid unit portions, and the electromagnetic band gap layer consists of a number of pins protruding from the walls of each grid unit portion.

It is disclosed a waveguide array antenna for satellite communications. The antenna is configured to transmit and/or receive a first polarization signal and a second polarization signal, the second polarization being orthogonal to the first polarization, and comprises an array of unit cells, each comprising a radiating element. The antenna comprises: a grid configured to divide each radiating element into sub-elements having an inter-element distance lower than or equal to the wavelength at a highest frequency of operation of the antenna; and an electromagnetic band gap layer configured to support the grid above the radiating elements. The grid comprises a number of grid unit portions, and the electromagnetic band gap layer consists of a number of pins protruding from the walls of each grid unit portion.

Provided is a waveguide module for improving insertion loss and return loss. The waveguide module includes a metal jig including a waveguide through which a radio wave is transmitted and received formed therein, a chip disposed on the waveguide formed in the metal jig and including a plurality of circuits that is configured to transmit and receive radio waves inside the waveguide, and a circuit board configured to provide a bias used for an operation of the chip, wherein the metal jig includes a trench structure to dispose a radio wave absorber on a side surface of the chip in a direction crossing the waveguide.

Provided is a waveguide module for improving insertion loss and return loss. The waveguide module includes a metal jig including a waveguide through which a radio wave is transmitted and received formed therein, a chip disposed on the waveguide formed in the metal jig and including a plurality of circuits that is configured to transmit and receive radio waves inside the waveguide, and a circuit board configured to provide a bias used for an operation of the chip, wherein the metal jig includes a trench structure to dispose a radio wave absorber on a side surface of the chip in a direction crossing the waveguide.

A septum polarizer according to one embodiment can comprise a waveguide body and a stair-shaped septum, which is arranged in the longitudinal direction inside the waveguide body and divides the waveguide body into two parts, and has stepped parts of different heights so that a higher order mode can be reduced in a preset frequency band. In addition, a septum polarizer according to one embodiment can comprise: a waveguide body having a polygonal cross-section; a stair-shaped septum, which is arranged in the longitudinal direction inside the waveguide body and divides the waveguide body into two parts; and a pleated part arranged on the outer surface of the waveguide body, and thus a higher order mode can be reduced in a preset frequency band.