公开(公告)号：US20020014983A1

公开(公告)日：2002-02-07

申请号：US09921210

申请日：2001-08-02

Applicant: Nokia Networks Oy

Inventor： Mauri Honkanen ,  Jouko Vankka

IPC: H03M001/66

CPC classification number: H03B28/00

Abstract: Simplifying functions representing raised sine or cosine curves to functions representing simple sine or cosine curves makes it possible to implement an electrical equivalent circuit for a ramp generator. The core of the ramp generator with an output power level controller is second-order direct-form feedback structure (60), which forms a digital sinusoidal oscillator. The initial values of two state variables x2(n), x2(nnull1) of the oscillator are chosen so that they both contain a predetermined first constant value. This first constant value will emerge as the amplitude value of the pure sine wave generated by the oscillator. Particularly the first constant value is equal to the desired nominal level A of the ramp minus the starting level. A second constant value (Anulldc) is added to the oscillator output. The added result is scaled (66) so that the nominal power level is A. A multiplexer (67) keeps the power level between the ramps constant.