Abstract: The invention relates to a linearization method for an RF amplifier and an arrangement implementing the method. A difference between an output signal of the amplifier and an unpredistorted input signal supplied to the amplifier is formed from baseband, quadrature components by means of a complex LMS algorithm in adaptation means. On the basis of the signal difference, the non-linearity of the amplifier is adaptively corrected before a quadrature modulator by changing the values of the complex quadrature components of the baseband signal by means of digital predistortion coefficients retrieved from a memory.

Abstract: The present invention discloses a linearisation and modulation device for a power amplifier.

Abstract: The present invention discloses a linearisation and modulation device for a power amplifier.

Abstract: A press section of a paper machine includes a first upper fabric, a pick-up suction roll within a loop of the first upper fabric for transferring a web from the forming wire of the paper machine onto the first upper fabric, a first lower fabric, a lower first press roll within a loop of the first lower fabric forming a first double-felted nip with the pick-up suction roll, a smooth-surfaced center roll, a second press roll situated within the loop of the first upper fabric forming a second single-felted nip with the center roll through which the first upper fabric passes, and wherein the first upper fabric has a substantially straight run between the first double-felted nip and the second single-felted nip.

Abstract: In a paper making machine, transfer apparatus for guiding a paper web from the press section to the drying section includes a smoothing press including upper and lower smoothing press rolls wherein the web is passed from the press section to the smoothing nip either directly or guided by a guide roll. The lower smoothing press roll of the smoothing press is substantially situated at a position which is normally occupied by a so-called baby or lead-in cylinder of a conventional drying section and the drying wire of the drying section is guided over a sector of the lower smoothing roll which is of a size sufficiently large that the web is transferred onto the drying wire which then carries the web as a closed draw onto the first drying cylinder of the drying section and, preferably, to the subsequent drying cylinders as a so-called single-fabric draw.

Abstract: A multi-nip press portion or section of a paper or cardboard machine wherein a web is detached from a forming wire by a pick-up roller and transferred onto a first fabric which carries the web into the first nip and wherein the press section includes at least two water-removing press nips which include a common smooth-surface central roller. The central roller has a downwardly facing open sector with which a scraper is associated for passing the web in the case of a break to a pulper or the like. The first nip, which can constitute a press nip and/or a transfer nip is formed by a counter-roller situated in nip-defining relationship with the pick-up roller. A second fabric passes through the first nip over the counter-roller and carries the web on its upper face from the first nip to a second double-fabric nip through which the second fabric, constituting a lower fabric, and a third fabric, constituting an upper fabric pass.

Abstract: A press section in a paper machine includes a first double felted press nip defined by first and second rolls through which first upper and second lower felt fabrics pass and at least two single felted press nips defined with a plain surface roll, the first felt fabric passing through a first one of the single felted press nips. The press section includes only non-suction rolls, the first and second rolls defining the first double felted press nip each having a solid shell and recessed surface. The first felt fabric supports the web leaving the wire section and is guided over a first sector of the first recessed surface roll wherein the direction thereof is changed so as to be directed generally upwardly prior to the first double felted press nip. The second lower felt fabric which passes through the first double felted press nip is guided over a second sector of the first recessed surface roll which comprises at least a substantial portion of the first sector thereof to provide external support for the web.

Abstract: A paper-manufacturing machine and method include the feature of detaching a web from a forming wire by utilizing a stationary transfer suction box past which a felt travels while contacting the web so that the latter becomes detached from the forming wire and adheres to the felt while travelling with the latter beyond the forming wire. The felt and web are lapped through a substantial angle around a roll having a recessed surface whiletravelling toward the first press nip of a press section, and at this roll around which the felt and web are lapped a means is provided for directing steam toward the web and through the latter and the felt inwardly toward the recessed surface of the guide roll so that the flowing steam will on the one hand heat water carried by the web to enhance dewatering of the web at the first press nip while on the other hand the steam will serve to maintain the web reliably in engagement with the felt as the latter travels toward the first press nip.

Abstract: A Yankee paper machine, particularly for the production of MG (machine glazed) paper and creped tissue, in which the formed paper web is sandwiched between a Yankee felt and a lower felt, pressed in a first nip between a suction roll and a dewatering roll, carried on the Yankee felt around the suction roll and pressed in a second nip between the suction roll and a Yankee cylinder. The web is adhered to the Yankee cylinder and the Yankee felt is detached from the web, passed around separate rolls and returned to the web on the Yankee cylinder in a third nip which in which adherance of the web to the Yankee cylinder is assured.

Abstract: Wood pulp is delignified and bleached with oxygen in the presence of a mixture of an alkali, a magnesium compound and TEA.