Abstract: An optical amplifier having high overall gain and low gain tilt, useful in an optical transmission system or the like. The amplifier has a doped optical fiber as the amplification medium and two pumps, the shorter wavelength one propagating with the signal being amplified and the longer wavelength one propagating opposite the signal being amplified. A wavelength selective reflective fiber grating is disposed along the doped fiber to reflect the second pump signal. The addition of the grating allows the amplifier to have a higher gain with a lower gain tilt than amplifiers without the grating. Positioning the grating along the fiber allows for the control of the overall gain with respect to the gain tilt for a given fiber length.

Abstract: A physically compact, multichannel wireless communication transceiver architecture employs overlap and add or polyphase signal processing functionality, for wideband signal processing, together with a sample rate. A receiver section receives a plurality of multiple frequency communication channels and outputs digital signals representative of the contents of the plurality of multiple frequency communication channels. The receiver section contains an FFT-based channelizer that processes the digital signals output by a wideband digital receiver and couples respective channel outputs to a first plurality of digital signal processor units, which process (e.g. demodulate) respective ones of the digital channel signals and supply processed ones of the digital channel signals at respective output ports for distribution to an attendant voice/data network.

Abstract: A forage harvester includes front and rear sets of upper and lower feed rolls that cooperate to convey a mat of crop material across a shear bar with which a cutterhead cooperates to cut the crop into short lengths. The front set of feed rolls and the upper feed roll of the rear set are contained in a feed roll housing including a movable frame section that is horizontally pivotally mounted to a fixed frame section, containing the cutterhead, shear bar and lower feed roll of the rear set of feed rolls, for movement between a normal working position and service position permitting easy access to the shear bar.

Abstract: A sensing unit for a row crop harvester guidance system is simply attachable and retrofittable to commercially available headers. The header comprises first and second crop dividers, each having a pair of sidewalls. A crop receiving passageway is formed between the dividers. The sensing unit comprises a rotatably mounted crop engaging arm biased into a crop engaging position in which the arm is disposed in the passageway. For mounting the unit includes a frame member which is fixed to the divider sidewalls with either bolts or clamping plates. Forwardly converging edges of the frame member are received within a tip on the forward end of the divider. The unit may be alternately fixed to dividers having different sizes and corresponding to different row spacings.

Abstract: A sensing unit for a row crop harvester guidance system is attached to a row crop harvester header. The header includes first and second crop dividers. Each divider has a pair of sidewalls. A crop receiving passageway is formed between the dividers. The unit comprises a rotatably mounted crop engaging arm biased into a crop engaging position by a torsion spring. In the crop engaging position the arm projects outwardly from one sidewall of one of the dividers into the passageway. The spring tension is adjustable to vary the amount of force required to actuate the crop engaging arm. Variation in the force is desirable to permit the sensing unit to operate reliably in a variety of crop and field conditions. Rotation of the crop engaging arm is limited by a shock absorbing guide movable in a slot in the sensing unit frame. The sensing unit has a housing for shielding critical components mounted on the unit from exposure to dirt and debris.