36results about How to "Compensation for non-linearity" patented technology

The invention discloses a measurement circuit of an LVDT (Linear Variable Differential Transformer). The measurement circuit comprises a sinusoidal pulse width modulator, a signal conditioning circuit, a linear variable differential transformer, a first sampling circuit, a second sampling circuit and a controller; the sinusoidal pulse width modulator is used for outputting pulse width and frequency-adjustable rectangular wave signals; the input end of the signal conditioning circuit is connected with the sinusoidal pulse width modulator; the signal conditioning circuit outputs amplitude and frequency adjustable sinusoidal wave signals; the primary coil of the linear differential transformer is connected with the output end of the signal conditioning circuit to receive the sinusoidal wave signals as LVDT excitation signals; the secondary coil of the linear differential transformer outputs LVDT differential signals; the input end of the first sampling circuit is connected with the primary coil; the input end of the second sampling circuit is connected with the secondary coil; and the controller is connected with the output end of the first sampling circuit and the output end of the second sampling circuit and is used for performing amplitude normalization processing to output an LVDT linear position. With the measurement circuit of the LVDT, relatively complicated analog circuit parameter adjustment is avoided, zero-point residual voltage, phase drift and sensor nonlinearity can be effectively compensated. The measurement circuit has the advantages of high stability and can reduce measurement errors.

The invention discloses a GaAs HBT high-gain broadband linear transconductance unit circuit comprising an input stage subcircuit, a basic transconductance subcircuit, a linear subcircuit, a negative resistance subcircuit and a mirror current source subcircuit, wherein the input stage subcircuit is used for level shift of input differential voltages IN_P and IN_N and conducts shifted signals into the basic transconductance subcircuit; the basic transconductance subcircuit is used for converting the input differential voltage signals into differential current signals; the linear subcircuit is used for improving the linearity of the basic transconductance subcircuit; the negative resistance subcircuit is used for improving the gain of the transconductance circuit; and the mirror current source subcircuit is used for providing bias current for the rest circuits. The circuit is designed and manufactured by a GaAs HBT technology and has wide operation bandwidth; the adopted linear subcircuit can effectively complement the nonlinearity of the circuit and provides excellent linearity; and the negative resistance subcircuit is adopted to effectively solve the conflict between the high-gainrequirement of circuits and transistor saturation and improves high-gain performance.