33results about How to "Improve input dynamic range" patented technology

An acoustic sensor is provided according to certain aspects for non-invasively detecting physiological acoustic vibrations indicative of one or more physiological parameters of a medical patient. The sensor can include an acoustic sensing element configured to generate a first signal in response to acoustic vibrations from a medical patient. The sensor can also include front-end circuitry configured to receive an input signal that is based at least in part on the first signal and to produce an amplified signal in response to the input signal. In some embodiments, the sensor further includes a compression module in communication with the front-end circuitry and configured to compress portions of at least one of the input signal and the amplified signal according to a first compression scheme, the compressed portions corresponding to portions of the first signal having a magnitude greater than a predetermined threshold level.

An RF detector configured to provide two outputs, one being a function of the true RMS power level of an RF input signal, and the other being a function of the instantaneous / peak power of the RF input signal, normalized to the average power level. The RF detector includes a variable gain detection subsystem including a single detector or detector array that provides a representation of the power level of the RF input signal. The detector or detector array is common to both the RMS power detection channel and the instantaneous / peak power detection channel of the RF detector. A method of RF detection includes providing representations of the RF input signal at different gain levels, selecting one or more of the representations, and averaging the selected signals. The gain levels of the selected representations is adjusted to provide information about the average power level of the RF input signal.

An RF detector configured to provide two outputs, one being a function of the true RMS power level of an RF input signal, and the other being a function of the instantaneous / peak power of the RF input signal, normalized to the average power level. The RF detector includes a variable gain detection subsystem including a single detector or detector array that provides a representation of the power level of the RF input signal. The detector or detector array is common to both the RMS power detection channel and the instantaneous / peak power detection channel of the RF detector. A method of RF detection includes providing representations of the RF input signal at different gain levels, selecting one or more of the representations, and averaging the selected signals. The gain levels of the selected representations is adjusted to provide information about the average power level of the RF input signal.

A sample and hold circuit including a first arrangement for receiving an input signal; a second arrangement for sampling and holding the signal in response to a control signal; and a third arrangement for minimizing the change in an input transistor's base current when the circuit switches from track to hold or hold to track and for keeping the collector emitter voltage constant at the input transistor. An arrangement is disclosed to increase the dynamic current accuracy of a current mirror for a diode connected transistor, by holding the voltage across one transistor in the current mirror constant. Another arrangement is disclosed for holding collector to emitter voltage constant for intermediate transistors resulting in improved gain accuracy and linearity. In one embodiment, a dummy leg is added to isolate the output voltage from switching transients that occur when an intermediate transistor is turned on at the transition from track to hold.

An optical receiver preamplifier includes an inverting amplifier 1 and a current-voltage conversion element 2 connected between input and output terminals of the inverting amplifier 1. The inverting amplifier 1 includes a first transistor 3 having a gate connected to the input terminal In of the inverting amplifier 1, a second transistor 4 having a source connected to a drain of the first transistor 3 and a gate to which a predetermined voltage Vb is applied, and a load 5 connected to a drain of the second transistor 4. A third transistor 6 is connected between the input terminal In of the inverting amplifier 1 and a source of the second transistor 4.

The present invention comprises a pair of circuits (171, 172) within the first stage (100) of an AC signal pre-amplifier. The present invention reduces the current mismatch at the base of the first stage transistors (141, 142, 143, 144) resulting in faster switching times by reducing input stage offset and, hence improving input dynamic range.

The invention relates to an oscilloscope with an improved front-end circuit, the oscilloscope includes a front-end circuit and a control processing module, the front-end circuit includes an input stage buffer and addition circuit, a gain selectable amplification module, an A / D conversion circuit and a D / A conversion circuit , the input stage buffering and adding circuit sequentially passes through the gain optional amplification module and the A / D conversion circuit to the control processing module, the gain selection output end of the control processing module is connected to an input end of the gain optional amplification module , the other output terminal of the control processing module provides a front-end circuit bias signal through the D / A conversion module, and the bias signal is output to the input stage buffer and adding circuit. The oscilloscope of the present invention improves the minimum resolution of ADC input, reduces the demand for analog front-end gain, and uses the switching of amplifiers with several gains at the same time, combined with digital gain, which not only saves costs, but also improves the input ADC signal. signal-to-noise ratio.

The invention discloses an oximetry front-end direct-current filtering circuit applicable to a smart band. The oximetry front-end direct-current filtering circuit applicable to the smart band comprises a signal primary input end, wherein the signal primary input end is sequentially connected with a TIA (Totally Integrated Automation) circuit, a controllable bias reduction circuit, a secondary amplifying circuit, an ADC sampling circuit and a processor; a draw-off current circuit is also connected between the signal primary input end and the TIA circuit, and is connected with the processor; the processor is used for controlling the draw-off current circuit to adjust the current signal strength of the signal initial input end. The invention also discloses an adjustment method of the oximetry front-end direct-current filtering circuit applicable to the smart band, and the exposure intensity of an oximetry signal can be further improved without worrying about the saturation of the TIA circuit through adding the draw-off current circuit, so that the dynamic range of the TIA circuit is enlarged in another way. Meanwhile, by the adjustable draw-off current capacity of the draw-off current circuit and a feedback mechanism of the processor, the prime draw-off current capability can be adjusted in real time, and the oximetry front-end direct-current filtering circuit can adapt to different environments.

A CMOS voltage comparator, comprising: a multistage amplifier, the first output terminal of each stage amplifier is connected to the first input terminal through a switch, the second output terminal is connected to the second input terminal through a switch, and the two switches are connected simultaneously Open or closed; the input terminal of each stage amplifier is connected to the output terminal of the previous stage amplifier, and the switches of all amplifiers are opened or closed at the same time; double-ended input to single-ended output conversion circuit, the input terminal is connected to the output terminal of the last stage amplifier Connected; multi-stage output shaping circuit, the input end is connected to the output end of the double-ended input to single-ended output conversion circuit; the DC blocking capacitor is located before the amplifiers of all levels and the input end of the double-ended input to single-ended output conversion circuit; the first The switch, the input signal is connected to the first-stage amplifier after passing through the first switch and the DC blocking capacitor; the second switch, the input signal is grounded after passing through the second switch, and the second switch is opened or closed simultaneously with all switches of the multi-stage amplifier.

A receiver stage for receiving a receive signal comprises M receiving paths, each receiving path comprises a signal processor and K comparators. The signal processors of the M receiving paths are configured to generate, for each of the M receiving paths, an amplified version of the receive signal, such that an amplification gain of the respective receiving path increases from a first of the M receiving paths to a last of the M receiving paths. For each of the M receiving paths the K comparators of the respective receiving paths are configured to compare the amplified receive signal of the respective receiving path with a respective threshold value. For each of the M receiving paths the threshold value increases from a first of the K comparators to the last of the K comparators.

The invention relates to an air interface analyzing device of a TD-LTE (Time Division-Long Term Evolution) system. The air interface analyzing device of the TD-LTE system comprises an antenna unit, wherein the antenna unit is in wireless RF (Radio Frequency) communication with an RF unit, local oscillator signals of a first local oscillator unit and a second local oscillator unit are output to the RF unit, the output end of the RF unit is connected with the input end of an intermediate frequency unit, the output end of the intermediate frequency unit is connected with the input end of a controller through a transmission unit, and the controller is connected with a display unit which is used for displaying an analyzing result through a signal hierarchical analyzing unit. According to the air interface analyzing device of the TD-LTE system, disclosed by the invention, the power of an input TD-LTE signal can be controlled through the RF unit, and the maximum input signal ability of the TD-LTE signal can be increased; and through the intermediate frequency unit, the input dynamic range of the TD-LTE signal can be increased, the parallel processing can be conducted, the analyzing function of TD-LTE air interface signals of multiple frequency points can be achieved, and the analyzing accuracy of the TD-LTE air interface signals can be increased through the method of separately processing the upstream and the downstream of the TD-LTE signal.

The invention provides a self-adapting burst-mode signal receiving and regenerating amplifier, relating to the technical field of digital communication. The prior art has the defects of low receiving sensitivity and no self-adapting capability. The amplifier of the invention comprises an AC coupling circuit, a high-pass filtering circuit and a positive feedback amplifying circuit. By combining a series of high and low pass filters and a multistage amplifier, the bit-by-bit recovery of burst-mode signals is realized, and the receiving sensitivity is improved. The whole processes of input, amplification, regeneration and output of signals are automatically finished. The invention has perfect self-adapting functions.

The invention discloses a demodulator circuit for a UHF (Ultrahigh Frequency) radio frequency identification label chip. Aiming at the defect of smaller dynamic range brought by the substitution of a traditional grid-grounded MOS (Metal-Oxide Semiconductor) tube for a high-resistance resistor, the invention provides a demodulator circuit which comprises an overvoltage protection circuit and a mean value generating circuit. The demodulator circuit connects the grid of a first PMOS (P-Channel Metal Oxide Semiconductor) tube in the mean value generating circuit with the grid of a first NMOS (N-Channel Metal Oxide Semiconductor) tube in the overvoltage protection circuit, and the grid level of the first PMOS tube automatically varies with the source level thereof by the partial pressure action of a second PMOS tube and a second resistor when the source level of the first PMOS tube rises or falls so that the absolute values of a grid voltage and a source voltage of the first PMOS tube are kept stable, the first PMOS tube has stable equivalent resistance in a large dynamic range, and the demodulator circuit of the invention has greater dynamic input range compared with the traditional demodulator circuit.