Abstract: System including a dual-fed antenna element is designed to present 2×2 port impedances that guarantee high efficiency operation of the main- and auxiliary transistors at peak- and backed off power. The proposed solution eliminates the need for lossy power combining, such as PCB based circuit combining or impedance matching networks between the antenna element and the main- and auxiliary amplifiers. The power from the main- and auxiliary transistors are combined at the circuit level by the antenna element.

Abstract: System including a dual-fed antenna element is designed to present 2×2 port impedances that guarantee high efficiency operation of the main- and auxiliary transistors at peak- and backed off power. The proposed solution eliminates the need for lossy power combining, such as PCB based circuit combining or impedance matching networks between the antenna element and the main- and auxiliary amplifiers.

Abstract: The present invention relates to a transition arrangement (100) comprising a transition between a substrate integrated waveguide, SIW, (20) of a circuit arrangement and a waveguide and/or antenna structure (10). It comprises a first conducting plate (1) and a second conducting plate (2). The SIW (20) is arranged on said first conducting plate, and an impedance matching structure (4) is connected to the second conducting plate.

Abstract: The present invention relates to a transition arrangement (100) comprising a transition between a substrate integrated waveguide, SIW, (20) of a circuit arrangement and a waveguide and/or antenna structure (10). It comprises a first conducting plate (1) and a second conducting plate (2). The SIW (20) is arranged on said first conducting plate, and an impedance matching structure (4) is connected to the second conducting plate.

Abstract: A multi-mode composite antenna includes two crossed dipole elements each consisting of a bow-tie antenna having two bow-tie antenna segments, and a conductive tube which houses signal transmission lines connected to each bow-tie antenna segment. A conductive flared portion surrounds the conductive tube and forms a monopole element. The bow-tie antenna segments are shaped so that slots extend between each adjacent bow-tie antenna, each slot forming a tapered slot antenna that has a pair of non-linear curved edges that diverge from each other.

Abstract: A multi-mode composite antenna includes two crossed dipole elements each consisting of a bow-tie antenna having two bow-tie antenna segments, and a conductive tube which houses signal transmission lines connected to each bow-tie antenna segment. A conductive flared portion surrounds the conductive tube and forms a monopole element. The bow-tie antenna segments are shaped so that slots extend between each adjacent bow-tie antenna, each slot forming a tapered slot antenna that has a pair of non-linear curved edges that diverge from each other.

Abstract: A multi-mode composite antenna is disclosed. The antenna includes at least two dipole elements, each dipole element having two arms with a signal transmission line connected to each arm, a conductive tube in which the signal transmission lines extend which forms a shield for the signal transmission lines, and an extension of the conductive tube. In one embodiment, the extension is formed by the conductive tube being folded back over itself. The dipole elements are capable of being excited by at least one differential mode excitation to realize a dipole radiation pattern, and the extension forms a monopole element with a monopole radiation pattern when at least one dipole element is excited by a common mode excitation. The composite antenna is capable of a combined monopole and dipole radiation pattern through the application of both differential mode excitation and common mode excitation.

Abstract: A multi-mode composite antenna is disclosed. The antenna includes at least two dipole elements, each dipole element having two arms with a signal transmission line connected to each arm, a conductive tube in which the signal transmission lines extend which forms a shield for the signal transmission lines, and an extension of the conductive tube. In one embodiment, the extension is formed by the conductive tube being folded back over itself. The dipole elements are capable of being excited by at least one differential mode excitation to realize a dipole radiation pattern, and the extension forms a monopole element with a monopole radiation pattern when at least one dipole element is excited by a common mode excitation. The composite antenna is capable of a combined monopole and dipole radiation pattern through the application of both differential mode excitation and common mode excitation.

Abstract: An amplifier for use in, for example, Public Address Systems to send audio signals over long distances, is of the push-pull type and includes a first and a second switch and an output transformer having a primary winding coupled to the switches and a secondary winding coupled to the output of the push-pull amplifier. The output transformer further includes a further secondary winding coupled to a comparator as a feedback loop.

Abstract: Amplifiers are known and are for example used in Public Address Systems to send audio signals over long distances.