Patent ID: 7598787
Filing Date: 2009-10-06
Classification: H03B,H03C,H03F,H03K

Abstract:
1. A signal generation apparatus comprising: an oscillator generating differential signals; a duty cycle adjusting circuit adjusting duty cycles of differential output signals in response to at least one control signal in the form of a current in the duty cycle adjusting circuit to adjust respective phases of the differential output signals generated according to a result of amplifying a difference between the differential signals input through a pair of input terminals and outputting duty cycle adjusted differential output signals to a pair of output terminals without feedback; and a signal generation circuit connected to the duty cycle adjusting circuit and outputting an in-phase signal and a quadrature phase signal in response to the duty cycle adjusted differential output signals, wherein the duty cycle adjusting circuit comprises; a first differential amplifier having a first current source producing a first control current and amplifying a difference between the differential signals input through the pair of input terminals and outputting first differential output signals of said duty cycle adjusted differential output signals to the air of output terminals; and a second differential amplifier having a second current source producing a second control current and amplifying a difference between the differential signals input through the pair of input terminals and outputting second differential output signals of said duty cycle adjusted differential output signals to the pair of output terminals, wherein the duty cycles of the first differential output signals are adjusted based on the first control current flowing in the first current source, and duty cycles of the second differential output signals are adjusted based on the second control current flowing in the second current source.