Apparatus for dual-band antenna and communications tower comprising such apparatus are provided. The apparatus comprises a first part (202) comprising first and second propagation paths configured to selectively propagate signals of a first frequency with either a first polarization state or a second polarization state, a transition part (204) rotatable between first and second transition positions to selectively propagate signals of a second frequency along the second signal path with the first polarisation state when in the first transition position and with the second polarisation state when in the second transition position and a rotator part rotatable between first and second rotator positions. Wherein, the rotator part is configured to orientate the polarisation of signals in the second signal path in order to couple the second signal path to an interface, and allow propagation of signals in the first signal path in either the first or second rotator positions.

A vehicle having a communication system is disclosed. The system includes two electrical couplings, coupled by way of a rotary joint having a bearing waveguide. Each electrical coupling includes an interface waveguide configured to couple to external signals. Each electrical coupling also includes a waveguide section configured to propagate electromagnetic signals between the interface waveguide and the bearing waveguide of the rotary joint. Additionally, the rotary joint is configured to allow one electrical coupling to rotate with respect to the other electrical coupling. An axis of rotation of the rotary joint is defined by a center of a portion of the waveguides. Yet further, the rotary joint allows electromagnetic energy to propagate between the waveguides of the electrical couplings.

Electrical instrument for applying radiofrequency and/or microwave frequency energy to tissue, comprising: a distal part comprising an instrument tip for applying radiofrequency and/or microwave frequency energy to tissue, the instrument tip comprising first and second conductive elements; a coaxial feed cable comprising an inner conductor, a tubular outer conductor coaxial with the inner conductor, and dielectric material separating the inner and outer conductors, the coaxial feed cable being for conveying radiofrequency and/or microwave frequency energy to the distal part; wherein: the inner conductor is electrically connected to the first conductive element and the outer conductor is electrically connected to the second conductive element through a rotatable connection between the distal part and the coaxial feed cable that allows rotation of the distal part relative to the coaxial feed cable; and the instrument comprises an actuator for rotating the distal part in a first rotational direction relative to the feed cable.

A vehicle having a communication system is disclosed. The system includes two electrical couplings, coupled by way of a rotary joint having a bearing waveguide. Each electrical coupling includes an interface waveguide configured to couple to external signals. Each electrical coupling also includes a waveguide section configured to propagate electromagnetic signals between the interface waveguide and the bearing waveguide of the rotary joint. Additionally, the rotary joint is configured to allow one electrical coupling to rotate with respect to the other electrical coupling. An axis of rotation of the rotary joint is defined by a center of a portion of the waveguides. Yet further, the rotary joint allows electromagnetic energy to propagate between the waveguides of the electrical couplings.

Electrical instrument for applying radiofrequency and/or microwave frequency energy to tissue, comprising: a distal part comprising an instrument tip for applying radiofrequency and/or microwave frequency energy to tissue, the instrument tip comprising first and second conductive elements; a coaxial feed cable comprising an inner conductor, a tubular outer conductor coaxial with the inner conductor, and dielectric material separating the inner and outer conductors, the coaxial feed cable being for conveying radiofrequency and/or microwave frequency energy to the distal part; wherein: the inner conductor is electrically connected to the first conductive element and the outer conductor is electrically connected to the second conductive element through a rotatable connection between the distal part and the coaxial feed cable that allows rotation of the distal part relative to the coaxial feed cable; and the instrument comprises an actuator for rotating the distal part in a first rotational direction relative to the feed cable.

A vehicle having a communication system is disclosed. The system includes two electrical couplings, coupled by way of a rotary joint having a bearing waveguide. Each electrical coupling includes an interface waveguide configured to couple to external signals. Each electrical coupling also includes a waveguide section configured to propagate electromagnetic signals between the interface waveguide and the bearing waveguide of the rotary joint. Additionally, the rotary joint is configured to allow one electrical coupling to rotate with respect to the other electrical coupling. An axis of rotation of the rotary joint is defined by a center of a portion of the waveguides. Yet further, the rotary joint allows electromagnetic energy to propagate between the waveguides of the electrical couplings.

Electrical instrument for applying radiofrequency and/or microwave frequency energy to tissue, comprising: a distal part comprising an instrument tip for applying radiofrequency and/or microwave frequency energy to tissue, the instrument tip comprising first and second conductive elements; a coaxial feed cable comprising an inner conductor, a tubular outer conductor coaxial with the inner conductor, and dielectric material separating the inner and outer conductors, the coaxial feed cable being for conveying radiofrequency and/or microwave frequency energy to the distal part; wherein: the inner conductor is electrically connected to the first conductive element and the outer conductor is electrically connected to the second conductive element through a rotatable connection between the distal part and the coaxial feed cable that allows rotation of the distal part relative to the coaxial feed cable; and the instrument comprises an actuator for rotating the distal part in a first rotational direction relative to the feed cable.

Electrical instrument for applying radiofrequency and/or microwave frequency energy to tissue, comprising: a distal part comprising an instrument tip for applying radiofrequency and/or microwave frequency energy to tissue, the instrument tip comprising first and second conductive elements; a coaxial feed cable comprising an inner conductor, a tubular outer conductor coaxial with the inner conductor, and dielectric material separating the inner and outer conductors, the coaxial feed cable being for conveying radiofrequency and/or microwave frequency energy to the distal part; wherein: the inner conductor is electrically connected to the first conductive element and the outer conductor is electrically connected to the second conductive element through a rotatable connection between the distal part and the coaxial feed cable that allows rotation of the distal part relative to the coaxial feed cable; and the instrument comprises an actuator for rotating the distal part in a first rotational direction relative to the feed cable.

Electrical instrument for applying radiofrequency and/or microwave frequency energy to tissue, comprising: a distal part comprising an instrument tip for applying radiofrequency and/or microwave frequency energy to tissue, the instrument tip comprising first and second conductive elements; a coaxial feed cable comprising an inner conductor, a tubular outer conductor coaxial with the inner conductor, and dielectric material separating the inner and outer conductors, the coaxial feed cable being for conveying radiofrequency and/or microwave frequency energy to the distal part; wherein: the inner conductor is electrically connected to the first conductive element and the outer conductor is electrically connected to the second conductive element through a rotatable connection between the distal part and the coaxial feed cable that allows rotation of the distal part relative to the coaxial feed cable; and the instrument comprises an actuator for rotating the distal part in a first rotational direction relative to the feed cable.

A transition arrangement for interconnection of waveguide structures or waveguide flanges for forming a waveguide twist, wherein a waveguide twist section arrangement including a number of waveguide twist sections is arranged between the waveguide structures or waveguide flanges for rotating the polarization of waves or signals twisted or forming an angle with an adjacent waveguide flange and/or another adjacent waveguide twist section with respective waveguide openings. The or each twist section on at least one side includes a surface of a conductive material with a periodic or quasi-periodic structure formed by a number of protruding elements allowing waves to pass across a gap between a surface around a waveguide opening to another waveguide opening in a desired direction or waveguide paths, at least in an intended frequency band of operation, and to stop propagation of waves in the gap in other directions.