Device for filtering and demodulating multipath signals

[0013] Examples:

[0014] As shown in Figure 1, the present invention includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7, diode D1, diode D2 , Operational amplifier A1, operational amplifier A2 and transistor T, resistor R7 and capacitor C5 are connected in parallel and resistor R7 and capacitor C5 are grounded, resistor R3 and resistor R6 are adjustable resistors, resistor R3 and resistor R6 are grounded; capacitor C1 The value is greater than the value of the capacitor C3, the value of the capacitor C2, the value of the capacitor C4 and the value of the capacitor C5 are equal. The capacitor C1, capacitor C2, the same direction input terminal of the operational amplifier A1, the output terminal of the operational amplifier A1, the diode D1, the diode D2, the output terminal of the operational amplifier A2, the same direction input terminal of the operational amplifier A2, and the capacitor C4 of this embodiment It is connected in series with the capacitor C3 to form a closed loop, and the common terminal of the capacitor C1 and the capacitor C3 is connected to the input signal. The common terminals of the cathodes of the diode D1 and the diode D2 in this embodiment are simultaneously connected to the base set of the transistor T, the resistor R7 and the capacitor C5. One end of the resistor R1 in this embodiment is connected to the common end of the capacitor C1 and the capacitor C2, and the other end is simultaneously connected to the inverting input and output ends of the operational amplifier A1; one end of the resistor R4 is connected to the common end of the capacitor C3 and the capacitor C4, and the other end is simultaneously connected The reverse input and output ends of the operational amplifier A2; the two ends of the resistor R2 are respectively connected to the output end of the capacitor C2 and the resistor R3; the two ends of the resistor R5 are respectively connected to the output end of the capacitor C4 and the resistor R6. The collector of the triode T in this embodiment is connected to the signal output terminal, and the emitter is grounded.

[0015] The input signal passes through two different filters at the same time. The first filter includes capacitor C1, capacitor C2, resistor R1, resistor R2, resistor R3, and operational amplifier A1. The second filter includes capacitor C3, capacitor C4, and resistor R4. , Resistor R5, resistor R6 and operational amplifier A2. When the signal filtered by the first filter passes through the transistor, the transistor is cut off and the output is open; when the signal filtered by the second filter passes through the transistor, the transistor is saturated and the output is short-circuited. When adjusting the circuit, input the frequency band of the first filter and the frequency band of the second filter into the circuit separately, adjust the adjustable resistance to maximize the output of the two filters, and realize the filtering and demodulation of the transmitted multiple signals at the same time. More practical.