78 results about "Gain measurement" patented technology

A transmitter-receiver having, a means for automatically determining the status of transmission medium such as optical fiber, and a means for automatically setting and resetting the transmission rate and/or output power according to the status of the transmission medium, a transmission loss and gain measurement method, and a transmitting-receiving system. A transmitter-receiver comprises at least: an output power controller for controlling the output power of a transmitter; an input power measuring section for measuring the strength of input signals; and an information processor for deriving the loss or gain of a path to change the output power of the transmitter and/or the rate of data transmission according to the derived loss or gain of the path. A transmission loss and gain measurement method applied to a system comprising transmission media and a plurality of the transmitter-receivers connected via the transmission media, comprises the steps of: transmitting information on the output power of a first transmitter-receiver from the first transmitter-receiver to a second transmitter-receiver; measuring reception strength by the second transmitter-receiver when the second transmitter-receiver receives the output power information; reading the output power information by the second transmitter-receiver; and comparing the reception strength with the output power information to calculate a transmission loss or gain by the second transmitter-receiver.

Apparatus and method for gain measurement and control of a Distributed Raman Amplifier (DRA). Various embodiments of the apparatus include a detection unit operative to measure, during operation of the DRA, the optical power of a filtered component of the light entering the DRA from the transmission fiber and a gain calculation and control unit coupled to the detection unit and operative to calculate a signal Raman gain property from the measured optical power. The filtered component may exemplarily be a result of passing the light through a band pass filter, a spectral filter with a given spectral shape or a notch filter. The signal Raman gain property may be an average on-off signal Raman gain, an average net signal Raman gain or a signal Raman gain tilt within a communication band. The apparatus and method may be used to operate the DRA in Automatic Gain Control, i.e. to maintain a required constant signal Raman gain and/or signal Raman gain tilt.

A PES linearization scheme using small excitation bode measurements is provided to account for non-linearity characteristics during measurements of head element positions so to generate a more accurate read and write operation by a head element of a disk drive assembly. The PES linearization scheme of this invention provides making gain measurements as the head element moves across the track, and then integrating the result to get a relative PES profile. By then finding two points on the profile a known distance apart, we can multiply the profile by the appropriate gain factor to get an absolute PES profile. This profile can be then be used as a look up table to convert raw PES numbers into actual position.

The invention discloses a quantum coherence effect-based antenna gain measuring device. The device comprises an electromagnetic wave absorbing chamber, an atomic gas chamber, a laser light source subsystem, a spectral signal measurement subsystem, a power measurement subsystem, an antenna gain measurement subsystem and a plurality of support platforms. According to the device disclosed by the invention, an optical device is used for triggering an energy spectrum, so that atoms are induced. An energy spectrum is obtained through photoelectric detection. Meanwhile, the wave-absorbing material isadopted to prevent an electromagnetic scattering body from affecting the measurement. Through measuring the feed-in net power of a measurement antenna and the net power of the coupling port of a directional coupler, the data acquisition of the transmitted spectrum of the detection light is completed. A power meter is connected with a computer through a GPIB bus, so that the reading of the feed-inpower value of the antenna is completed. Through an antenna gain measurement model (img file = 'DDA 0001510521350000011.T'wi = '355 'he = '170 '), the gain measurement is completed. Compared with a traditional antenna measuring system, the device has the advantages of high measurement precision, low construction cost, small occupied area and the like.

A hearing aid system and a method of estimating ambient noise in a listening device includes an input transducer and an output transducer, an electrical forward path between the input transducer and the output transducer providing a forward gain, an electrical feedback path comprising an adaptive filter for estimating the acoustic feedback gain from the output transducer to the input transducer. A method determines the quality of a critical gain measurement for a listening device. The method comprises a) monitoring the energy of the first-difference of the filter coefficients of the adaptive filter over time and b) applying a predefined threshold criterion to the change in energy content from one time instance to another to determine an acceptable impact of the ambient noise. This technique may e.g. be used for the fitting of hearing instruments where background noise is variable.

According to embodiments of the present technique, a system and a method for obtaining low-noise measurements for a wide range of analog signal strengths is provided. According to aspects of the present technique, a low-gain measurement of an input pixel charge is performed, wherein the input pixel charge is distributed to two feedback capacitors, which together provide a relatively low integrator gain. After the low-gain measurement, a high-gain measurement is performed, wherein one of the capacitors is remove from the feedback loop and the charge is redistributed to the remaining capacitor.

The invention relates to a hearing aid system comprising an input transducer for converting an input sound signal comprising an information signal part of a known waveform and a background noise part to an electrical analogue input signal, optionally an A/D converter for converting the electrical input signal to a digital input signal. The invention further relates to a method of making a critical gain measurement. The object of the present invention is to improve the signal-to-noise ratio of a signal to be measured or detected in a hearing instrument compared to prior art solutions. The problem is solved in that a matched filter receiving said analogue or digital input signal and optimized to improve the identification of the information signal part from the noisy input signal. An advantage of the invention is that it provides an alternative scheme for improving signal to noise ratio of a hearing aid. The invention may e.g. be used for the customization of hearing aid parameters in cooperation with fitting software and/or for improving signal to noise ratio of a detected or measured signal.

The invention relates to an automatic gain control device of a communication system. The automatic gain control device comprises a device body and an antenna, and is characterized in that the device body is connected with the antenna through a radio-frequency cable; and the device body comprises a clock module, a radio frequency receiving module, an analog-to-digital conversion module, a basebandmodule, a digital-to-analog conversion module, a radio frequency transmitting module, a conditioning selection module, a terminal processing module and a power supply module. The invention further comprises a gain measurement method and corresponding equipment in the automatic gain control device of the communication system. According to the invention, the receiving of signals in a large dynamic range is realized; the interference of instantaneous noise generated in the receiving process on demodulation is effectively avoided; the bit error rate is greatly reduced; the baseband data processingperformance is better improved; and the automatic gain control device of the invention has the advantages of higher flexibility, high control precision and wide application.

The invention discloses a hygroscopic weight increment measuring device for low-temperature and heat-insulating foam plastic. A constant-temperature high-humidity box, a sample sleeve, a liquid nitrogen trough, an external liquid nitrogen tank and an internal liquid nitrogen tank are connected in sequence; a flow guiding cover is sleeved outside the sample sleeve; a groove is arranged at the upper end of the constant-temperature high-humidity box; a G-10 washer is arranged in the groove; the inner wall of the constant-temperature high-humidity box is provided with a PTC (positive temperature coefficient) heating resistor and a fan; a water inlet system and a water discharging pipeline are arranged at the lower part of the constant-temperature high-humidity box; an ultrasonic generator anda miniature lifter is arranged at the bottom of the constant-temperature high-humidity box; a sample is mounted in the sample sleeve; a liquid nitrogen inlet pipe, a safety valve and an outlet shutoff valve are arranged at the top of the external liquid nitrogen tank; the liquid nitrogen inlet pipe is provided with a manual shutoff valve; the external liquid nitrogen tank and the internal liquid nitrogen tank are connected with the liquid nitrogen trough; a copper disc is welded at the bottom of the liquid nitrogen trough; the lower part of the external liquid nitrogen tank is provided with avacuumizing opening; and the outlet shutoff valve is connected with the flow guiding cover through a pipeline. By using the measuring device, the hygroscopic weight increment measurement of the sample is achieved in a high-humidity extreme environment with one side at a super-low temperature and the other side at a room temperature, and furthermore, the sample can be conveniently moved away and mounted.

The invention discloses a gain measuring device and method of a cascaded micro channel plate (MCP). The method comprises the following steps that: step (1) after being attenuated, ultraviolet light is emitted to a quartz window, and an ultraviolet Au photocathode is excited to emit photoelectrons; step (2) under the action of electric fields, the photoelectrons are emitted to the input end of the cascaded MCP, and are multiplied by the cascaded MCP, and the multiplied photoelectrons are outputted from the output end of the cascaded MCP, and the multiplied photoelectrons bombard a fluorescent screen under the action of the electric fields, so that bright spots can be generated; step (3) the bright spots on the fluorescent screen are imaged by a CCD or CMOS camera, and a computer acquires the output signals of the CCD or CMOS camera so as to measure the number of the bright spots; and (4) after the number of the bright spots is measured, a circuit is switched to the output current loop of the cascaded MCP, and a nanoammeter is connected in series in the loop so as to measure the output current of the cascaded micro channel plate (MCP), and the gain of the cascaded micro channel plate (MCP) is calculated according to the number of the bright spots and the output current of the cascaded micro channel plate (MCP). The gain measuring method of the cascaded micro channel plate (MCP) provided by the invention has the advantages of simple operation and high accuracy.

A method of testing a phased array antenna that includes a plurality of antenna element pairs, each antenna element pair of the plurality of antenna element pairs including a first antenna element and a second antenna element, the method including: for each antenna element pair of the plurality of antenna element pairs, performing a first cross element gain measurement from the first antenna element to the second antenna element of that antenna element pair; and determining whether there is a problem associated with the phased array antenna by examining the first cross element gain measurements for the plurality of antenna element pairs.

Optical transmission systems of the present invention include at least one optical amplifier configured to provide optical amplification of one or more information carrying optical signal wavelengths. At least one optical amplifier is controlled based on an in situ performance characterization of the at least one optical amplifier and the transmission fiber. The in situ, or installed, performance characteristics of the optical amplifier can be characterized based on relative gain measurements over the signal wavelength range as a function of the supplied pump power. The installed characterization allows the optical amplifier performance and gain profiles to be tightly controlled over the signal wavelength range in the transmission system.

The invention discloses an active reflective surface shape adjustment method based on axial gain measurement. According to the method, a series of micro-disturbance is applied to a reflective surfaceshape through an actuator network in an active surface system, and the change in antenna axial gain is measured in the disturbing process; a group of orthogonal basis functions defined on an antenna port surface are used as disturbance modes to disturb the surface shape one by one, and under each disturbance mode, a curve of the change in the antenna axial gain along with the disturbance quantityis recorded, and the optimal adjustment quantity under each disturbance mode is fitted out of the corresponding curve; and through a series of disturbance, measurement and adjustment processes, finally the antenna gain can reach a maximal value, and the surface shape error can reach a minimal value. The method has a low requirement on a detector, and a single-pixel power detector can be used; in the running process of a telescope, a scientific receiver and an astronomical point source target can be directly utilized to carry out surface shape measurement and adjustment frequently, and therefore the observation efficiency of the telescope in the running process is maintained.

Disclosed herein are detectors of audio ringing feedback, that is decaying feedback with a gain of less than one, those detectors utilizing a repeated gain measurement that applied to a range of gain values characteristic of ringing-type feedback. Those gain measurements, while in the range, increase a probability measurement of feedback. When the probability of feedback reaches a threshold, a detection of feedback is made and feedback countermeasures, such as the application of a notch filter, may be applied. Optionally, the audio gain around likely frequencies of feedback may be enhanced for a time to increase the resolution of identification of a feedback frequency, which may be identified through an interpolative method. Repeated gain measurements may also identify building-type feedback. A ringing detector may include more than one range of detection, for example for building, strong-ringing and weak-ringing feedback.