Other

Alliant Defense Electronics Systems, Inc.

Hercules Defense Electronics, Inc.

Richard W Johnson

Apparatus for linearizing the sweep frequency output of an FMCW radar employing a voltage controlled oscillator includes means for comparing a series of reference voltages sequentially with the instantaeous oscillator drive voltge, accumulating the individual resultant error voltages throughout successive sweep cycles, sequentially converting the individual accumulated voltages to exponential form and feeding the exponential voltages back into the drive circuit for the VCO.

Voltage feedback linearizer

A method and apparatus are provided for allocating tolerances. A total tolerance is specified (218) to be allocated among a plurality of variable tolerances each having an associated assembly feature. For each associated assembly feature, an associated first tolerance point is defined (202) at which a further decrease in a stringency of the variable tolerance fails to significantly decrease a cost of achieving the variable tolerance. For each associated assembly feature, an associated second tolerance point is defined (202) at which a further increase in the stringency begins to substantially increase the cost of achieving the variable tolerance. For each associated assembly feature, an associated third tolerance point is defined (202) at which a further increase in the stringency is not substantially achievable. The total tolerance is allocated (226, 232, 254, 266, 236, 242, 258, 270, 246) among the variable tolerances, such that the variable tolerances substantially satisfy a first predetermined relationship relative to the total tolerance, and such that each variable tolerance substantially satisfies a second predetermined relationship relative to its associated tolerance points.

Apparatus and method for allocating tolerances

Range resolution in an FMCW radar system is achieved by providing a periodic linear frequency sweep. The present invention assures the linearity of this sweep by using a negative feedback circuit which includes means for obtaining 16 sequential instantaneous frequency versus time slope measurements during each sweep cycle, generating a set of 16 sequential error signals and a corresponding set of correction voltages, and applying these correction voltages to the sweep drive voltage used to drive the voltage controlled oscillator that generates the frequency swept output signal.

Frequency feedback linearizer

A grass and ditch mower is provided having a novel floating cutting deck mounted to a novel extension arm assembly.

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Port Richey, FL, United States of America

Richard W Johnson