Patent ID: 7999587

Claim:
A circuit arrangement for applying predistortion to a baseband signal applied as a modulation signal to a pulse modulation circuit which generates a pulse-shaped signal, said circuit arrangement comprising: a. a detection unit configured to determine envelope information of said baseband signal, said envelope information comprising baseband components sin(θ 1 (t)), cos(θ 1 (t)), sin(θ 2 (t)), and cos(θ 2 (t)) with θ 1 (t)=Φ P (t)+Φ M (t)+Ψ(t) and θ 2 (t)=Φ P (t)−Φ M (t)+Ψ(t), wherein Φ P (t) is a phase of the baseband signal, Φ M (t) corresponds to a duty cycle d(t), and Ψ(t) is an extra phase predistortion to compensate for symmetric slewing; and b. a predistortion unit configured to supply the baseband components to the pulse modulation circuit which comprises four multipliers in order to multiply the baseband components by two sine- and cosine-shaped RF carrier signals, wherein at least one of the duty cycle and the phase of the baseband signal is modulated to generate additional predistortion for reducing slewing distortions in response to said determined envelope information.