Abstract: The antenna, particularly for portable televisions, comprises two ports coupled to a radiating element (11), the two ports being placed on the radiating element at 90° to each other and at 45° relative to a horizontal plane. The two ports are linked to a broadband switching and phase shifting circuit controlled in order to supply a polarization diversity signal as output.

Abstract: The present invention relates to an electromagnetic wave transmission/reception source for a multireflector antenna of the Cassegrain type comprising longitudinal-radiation means operating in a first frequency band and an array of n radiating elements of the travelling-wave type operating in a second frequency band with the n radiating elements arranged symmetrically around the longitudinal-radiation means, the array and the longitudinal-radiation means having an approximately common phase centre, the array of n radiating elements being excited by a waveguide of polygonal cross section. The invention applies especially in satellite communication systems operating in the C-, Ku- or Ka-bands.

Abstract: The invention proposes a transition 105 between a microstrip technology circuit and a waveguide 103, the waveguide (103) being furnished with a probe 122 linked electrically to the microstrip circuit. The transition comprises at least one first resonant cavity 127 coupled by a first hole 124 placed level with the said plane. The transition furnished with the cavity 127 behaves as a bandstop filter. The transition 105 is placed in an outside unit 1 of a transmission system comprising a transmit circuit embodied in microstrip technology and an antenna of waveguide type. A transmit circuit comprises at least one local oscillator and the resonant cavity 127 is tuned to the frequency of the local oscillator.

Abstract: The present invention relates to a broadband antenna with omnidirectional radiation comprising a first circular or semicircular monopole (3) perpendicular to an earth plane (1), and at least one second circular or semicircular monopole (4), the monopoles being positioned with respect to one another in such a way as to have a common diameter (z).

Abstract: The invention reduces the size of waveguide circuits. The invention proposes to change the cross section of a waveguide in a curved part. Thus, a curved element according to the invention makes it possible at the same time to make a change in waveguide cross action.

Abstract: A device for sending and receiving electromagnetic waves comprises an antenna with a waveguide, a sending card and a receiving card. The sending card and the receiving card each extend essentially from the waveguide, and therefore from the antenna axis, in a plane perpendicular to this axis and between them form an angle greater than 90°.

Abstract: The present invention relates to an electromagnetic wave transmission/reception source for a multireflector antenna of the Cassegrain type comprising longitudinal-radiation means (12) operating in a first frequency band and an array of n radiating elements (11) of the travelling-wave type operating in a second frequency band with the n radiating elements arranged symmetrically around the longitudinal-radiation means, the array and the longitudinal-radiation means having an approximately common phase centre, the array of n radiating elements being excited by a waveguide (15) of polygonal cross section.

Abstract: The present invention relates to a device for transmitting and/or receiving electromagnetic waves comprising at least one radiating element for radiating a circular polarization of given sense, characterized in that it comprises at least one means dimensioned and positioned with respect to the radiating element in such a way as to radiate, at the frequency of the radiating element, a circular polarization of opposite sense to that of the radiating element so as to compensate for the cross component of the radiating element. The invention applies more particularly to printed antennas operating under circular polarization.

Abstract: The invention reduces the size of waveguide circuits. The invention proposes to change the cross section of a waveguide in a curved part. Thus, a curved element according to the invention makes it possible at the same time to make a change in waveguide cross section.

Abstract: The present invention relates to a T-circuit produced using microstrip technology with two branches (2, 3) of identical length L2 comprising a phase-shifting element (6) producing a given phase shift &PHgr; by extending one of the branches, the T-circuit operating in broadband, the circuit comprises at least one elbow (4) extending the branch (3) without the phase-shifting element and the length L2 is equal to a multiple of &lgr;g/2 where &lgr;g is the guided wavelength.

Abstract: The present invention relates to a device for transmitting and/or receiving electromagnetic waves comprising at least one antenna with at least one radiating element transmitting and/or receiving signals of given polarization and a feed array produced in microstrip technology consisting of lines devised so as to give parasitic radiation. In this case, the feed array is devised and dimensioned in such a way that the parasitic radiation has the same direction and the same polarization as the radiation of the antenna and combines in-phase with the said radiation of the antenna.

Abstract: A device for sending and receiving electromagnetic waves comprises an antenna with a waveguide, a sending card and a receiving card. The sending card and the receiving card each extend essentially from the waveguide, and therefore from the antenna axis, in a plane perpendicular to this axis and between them form an angle greater than 90°.

Abstract: The invention relates to a device for emitting and/or receiving electromagnetic waves comprising a lens bringing a plurality of directions defined by the radiation space of the lens into correspondence with a plurality of focusing points defining a focusing surface of the lens, the lens comprising a shaped volume of dielectric material. According to the invention, the dielectric material comprises a granular agglomerate defined by a homogeneous or quasi-homogeneous distribution of granules of the same type and of small size with respect to the wavelength (&lgr;R, &lgr;T) of the electromagnetic waves to be received and/or emitted by the said device, the said granules being held under pressure in the said volume by holding means shaped according to the said volume. The invention also relates to a communications terminal comprising a device according to the invention.

Abstract: The present invention relates to a device for transmitting and/or receiving electromagnetic waves comprising at least one antenna with at least one radiating element transmitting and/or receiving signals of given polarization and a feed array produced in microstrip technology consisting of lines devised so as to give parasitic radiation. In this case, the feed array is devised and dimensioned in such a way that the parasitic radiation has the same direction and the same polarization as the radiation of the antenna and combines in-phase with the said radiation of the antenna.

Abstract: The present invention relates to a T-circuit produced using microstrip technology with two branches (2, 3) of identical length L2 comprising a phase-shifting element (6) producing a given phase shift &PHgr; by extending one of the branches, the T-circuit operating in broadband, the circuit comprises at least one elbow (4) extending the branch (3) without the phase-shifting element and the length L2 is equal to a multiple of &lgr;g/2 where &lgr;g is the guided wavelength.

Abstract: The present invention relates to a source-antenna for transmitting/receiving electromagnetic waves comprising an array of n radiating elements (113, 114) operating in a first frequency band, means (20) with longitudinal radiation operating in a second frequency band, the array and the means with longitudinal radiation having a substantially common phase centre, the n radiating elements being arranged symmetrically about the longitudinal-radiation means, and each element (113, 114) of the array consisting of a radiating element of the travelling wave type.

Abstract: The invention relates to a device for emitting and/or receiving electromagnetic waves comprising a lens bringing a plurality of directions defined by the radiation space of the lens into correspondence with a plurality of focusing points defining a focusing surface of the lens, the lens comprising a shaped volume of dielectric material.