Patent ID: 10992305

Abstract:
A method for initializing a phase adder circuit including a multiplier circuit with its two inputs receiving signals of frequency fo, a mixer circuit, an amplifier circuit, a low pass loop filter, and a voltage controlled oscillator (VCO), the method including: during a first phase, determining a reference voltage which when applied to the VCO causes it to produce a signal having a frequency of nf0; during a second phase, supplying a signal of frequency nfo to a first input of the mixer and a signal of frequency (nfo+Δf) to a second input of the mixer; and determining an adjustment signal which when applied to the amplifier circuit causes the amplifier circuit to output a signal having a DC component equal to the reference voltage; and during a third phase, forming a primary phase locked loop (PLL) circuit including the mixer, the amplifier circuit, the low pass loop filter and the VCO; and applying the adjustment signal to the amplifier circuit.