Frequency adaptive variable capacitance circuit

The utility model relates to a frequency adaptive variable capacitance circuit, incoming signal and reference signal insert the phase detection discriminator, and the latter is binary signal, input signal control electric charge pump module's s0, the break -make of s1 switch relatively to charge to the electric capacity matrix, comparator and electric capacity matrix are connected respectively in electric charge pump module's output, the control end and the shift counter of electric capacity matrix are connected to the output of comparator, the first detector is connected to the shift counter output, the output of electric capacity matrix produces electric capacity matrix branch voltage through resistance and inserts voltage controlled oscillator and comparator, and the first detector is connected to the voltage controlled oscillator output, and first detector output reference signal inserts the phase detection discriminator. Electric charge pump module includes 3 the same N type MOS transistors and 2 the same P type MOS transistors. The capacitance value of this circuit electric capacity matrix can not change according to incoming signal frequency self -adaptation ground, simple structure, low cost, can the wide application in the design of multimode multifrequency wave filter.