5778 results about "Band-pass filter" patented technology

A method for padding, filtering, denoising, image enhancing and increased time-frequency acquisition is described for digitized data of a data set where unknown data is estimated using real data by adding unknown data points in a manner that the padding routine can estimate the interior data set including known and unknown data to a given accuracy on the known data points. The method also provides filtering using non-interpolating, well-tempered distributed approximating functional (NIDAF)-low-band-pass filters. The method also provides for symmetric and/or anti-symmetric extension of the data set so that the data set may be better refined and can be filtered by Fourier and other type of low frequency or harmonic filters.

A hermetic terminal for an active implantable medical device (AIMD), includes an RF distance telemetry pin antenna, a capacitor conductively coupled between the antenna and a ground for the AIMD, and an inductor electrically disposed in parallel with the capacitor and conductively coupled between the antenna and a ground for the AIMD. The capacitor and the inductor form a band pass filter for attenuating electromagnetic signals through the antenna except at a selected frequency band. Values of capacitance and inductance are selected such that the band pass filter is resonant at the selected frequency band.

Flow rate measurement system includes two measurement regions 14,16 located an average axial distance .DELTA.X apart along the pipe 12, the first measurement region 14 having two unsteady pressure sensors 18,20, located a distance X.sub.1 apart, and the second measurement region 16, having two other unsteady pressure sensors 22,24, located a distance X.sub.2 apart, each capable of measuring the unsteady pressure in the pipe 12. Signals from each pair of pressure sensors 18,20 and 22,24 are differenced by summers 44,54, respectively, to form spatial wavelength filters 33,35, respectively. Each spatial filter 33,35 filters out acoustic pressure disturbances P.sub.acoustic and other long wavelength pressure disturbances in the pipe 12 and passes short-wavelength low-frequency vortical pressure disturbances P.sub.vortical associated with the vortical flow field 15. The spatial filters 33,35 provide signals P.sub.as1,P.sub.as2 to band pass filters 46,56 that filter out high frequency signals. The P.sub.vortical -dominated filtered signals P.sub.asf1,P.sub.asf2 from the two regions 14,16 are cross-correlated by Cross-Correlation Logic 50 to determine a time delay .tau. between the two sensing locations 14,16 which is divided into the distance .DELTA.X to obtain a convection velocity U.sub.c(t) that is related to an average flow rate of the fluid (i.e., one or more liquids and/or gases) flowing in the pipe 12. The invention may also be configured to detect the velocity of any desired inhomogeneous pressure field in the flow. The invention may also be combined with an instrument, an opto-electronic converter and a controller in an industrial process control system.

A hermetic terminal for an active implantable medical device (AIMD), includes an RF distance telemetry pin antenna, a capacitor conductively coupled between the antenna and a ground for the AIMD, and an inductor electrically disposed in parallel with the capacitor and conductively coupled between the antenna and a ground for the AIMD. The capacitor and the inductor form a band pass filter for attenuating electromagnetic signals through the antenna except at a selected frequency band. Values of capacitance and inductance are selected such that the band pass filter is resonant at the selected frequency band. In an alternative form, the band pass filter is coupled in series with the telemetry pin antenna for attenuating MRI signals of a selected frequency band.

A resonant switched power converter having switching frequency controlled in response to an output voltage thereof achieves over-current protection such as at start-up or under short circuit conditions using a resonant tank circuit which provides a notch filter in addition to a band pass filter. A additional band pass filter provided in the resonant tank circuit achieves increased power transfer to a load and reduced circulating resonant currents and conduction losses. The inductances of the preferred LCLCL tank circuit or other tank circuit with two pass band filters and a notch filter may be integrated into a single electrical component.

A band-pass filter has a ladder-type circuit including first and second terminals whose characteristic impedances are Z0, and series elements and shunt elements disposed between a first terminal and a second terminal, each of the series elements and shunt elements containing a film bulk acoustic resonator. Assuming that characteristic impedance of any one of the series elements is Z1 and that characteristic impedance of any one of the shunt elements is Z2, the characteristic impedances Z0, Z1, and Z2 have a relation of 1<(Z1/Z0)<2, preferably 1.3<(Z1/Z0)<1.7, and 0.5<(Z2/Z0)<1, preferably 0.6<(Z2/Z0)<0.8.

The band-pass filter has a stacked pair of film bulk acoustic resonators (FBARs) and an acoustic decoupler between the FBARs. Each of the FBARs has opposed planar electrodes and a layer of piezoelectric material between the electrodes. The acoustic decoupler controls the coupling of acoustic energy between the FBARs. Specifically, the acoustic decoupler couples less acoustic energy between the FBARs than would be coupled by direct contact between the FBARs. The reduced acoustic coupling gives the band-pass filter desirable in-band and out-of-band properties.

Provided are a depth camera and methods of measuring a depth image by using the depth camera. The depth camera is a time-of-flight (TOF) depth camera including: an illumination device that illuminates a patterned light to an object; a filter unit that reduces noise light included in light reflected by the object; and an image sensor that provides a depth image of the object by receiving light that enters through the filter unit. The illumination device includes: a light source; and a patterned light generator that changes the light emitted from the light source into the patterned light. The filter unit includes a band pass filter and an optical modulator. The patterned light generator may be a diffractive optical element or a refractive optical element.

A provided smart switch called Occupant Counter Control Switch, or OCCS, basically comprises of a motion sensor PIR, a photo sensor, an amplifier with band-pass filter, a microprocessor, a digital display, and a relay or triac to drive electrical appliances such as lights. The PIR sensor detects heat from a human body moving across it and generates a distinctive signal that is, unique to each of the two directions, further processed by the microprocessor for counting and thereby controlling the relay. Installed at the entrance of a room replacing the regular switch (see FIG. 1), the OCCS counts up, displaying a digit great than zero, upon detecting a person entering the room and turns on the lights if sensing insufficient ambient light. OCCS constantly energizes the lights during the room is occupied and immediately switches them off upon counting down to zero when detecting the last person exiting the room.

The band-pass filter has first terminals, second terminals, a first decoupled stacked bulk acoustic resonator (DSBAR), a second DSBAR, and an electrical circuit connecting the first DSBAR and the second DSBAR in series between the first terminals and the second terminals. Each DSBAR has a first film bulk acoustic resonator (FBAR), a second FBAR and an acoustic decoupler between the FBARs. Each FBAR has opposed planar electrodes and a piezoelectric element between the electrodes.

The band-pass filter has an upper film bulk acoustic resonator (FBAR), an upper FBAR stacked on the lower FBAR, and, between the FBARs, an acoustic decoupler comprising a layer of acoustic decoupling material. Each of the FBARs has opposed planar electrodes and a piezoelectric element between the electrodes. The acoustic decoupler controls the coupling of acoustic energy between the FBARs. Specifically, the acoustic decoupler couples less acoustic energy between the FBARs than would be coupled by direct contact between the FBARs. The reduced acoustic coupling gives the band-pass filter desirable in-band and out-of-band properties.

A data system 102 permits bus encoding based on frequency of the bus; an encoding scheme may be implemented to avoid undesirable frequency conditions such as a resonant condition that may lead to degradation in system performance. The device or integrated circuit will typically include an encoder; in one embodiment, the encoder is a data bus inversion (DBI) circuit that selectively inverts all lines of a data bus. A detector that may include a band-pass or stop-band filter that, for example, evaluates data for transmission on the bus to detect frequency, for example, a predetermined frequency or a frequency range. The detector provides a control signal for the encoder to selectively apply an encoding scheme as a function of frequency.

A tuner circuit includes a band selection filter coupled to receive an input RF signal and provide a band selected output signal where the band selection filter includes a bank of band pass filters. Each band pass filter includes an inductor and a variable capacitor forming an LC resonator where the inductor is an integrated planar spiral inductor. The tuner circuit further includes a frequency conversion circuit coupled to receive an input signal corresponding to the band selected output signal and provide a frequency converted output signal having a predetermined frequency. The integrated planar spiral inductor can be formed using a single metal spiral or multiple metal spirals. In a multi-spiral structure, a first metal spiral having an inward spiral pattern and a second metal spiral having an outward spiral pattern to form an inductor with large inductance, low series resistance and high Q values, even at low frequency.

In accordance with one aspect of the invention, methods and systems are disclosed for delivering a stimulating signal by a stimulating medical device having a plurality of electrodes. Such methods and systems comprise receiving a signal; filtering the received signal to obtain a plurality of band pass filtered signals; delivering to each electrode of a first group of one or more electrodes, a first set of stimulation signals, wherein the first set of stimulation signals comprises stimulations signals for each of a first group of two or more band pass filtered signals; and delivering to each of electrodes of a second group of one or more electrodes, a second set of stimulation signals, wherein the second set of stimulation signals comprises stimulations signals for each of a second group of one or more band pass filtered signals; and wherein the first set of stimulation signals are delivered at a different effective stimulation rate than the second set of stimulation signals.

The disclosed invention provides apparatus and methods that can convert frequencies of time-encoded signals. In one aspect, a down-converter circuit includes low-pass filters, a switch, a time encoder, and an output low-pass filter. In another aspect, an up-converter circuit includes an analog or digital input time encoder, low-pass filters, a switch, an output time encoder, and a time-encoded band-pass filter. In yet another aspect, a complete receiver system is provided. The receiver system can operate effectively with signals in the radio frequency range.

Systems and methods are described for a GPS receiver capable of functioning in the presence of interference. A method includes detecting an interfering signal including: tuning a band pass filter over a frequency range; and at each of a plurality of incremental frequencies: computing a set of band pass filter coefficients; sending the set of band pass filter coefficients to a digital filter; repeatedly transforming an analog-to-digital converter output having a quantization level in excess of 2 bits into a band pass filter output with the digital filter to obtain a plurality of samples; computing an average of the plurality of samples; and comparing the average to a threshold to detect peaks that exceed a threshold. An apparatus, comprising: an analog radio frequency circuit; an analog-to-digital converter coupled to the analog radio frequency circuit, the analog-to-digital converter providing a quantization level in excess of 2 bits; a digital filter coupled to the analog-to-digital converter; and a digital circuit coupled to the digital filter.

Loss of optical signal is detected in a synchronous communications system by detecting features of a monitor signal occurring at a detection frequency corresponding to the frame rate. Since the frame rate is substantially less than the bit rate, monitoring and detection can be performed at a lower bandwidth than the bit rate. An auto-correlation circuit utilises delays which are an integral multiple of the frame rate and produces a detection value which is compared with a threshold value. Alternatively, detection may be based on a power measurement of a band pass filtered monitor signal by setting the lower bandwidth limit above zero frequency and normalizing the measurement of power relative to an average power measurement. A loss of signal may then be detected by a change in power measurement relative to a threshold and can be used for asynchronous systems as well as synchronous systems. Loss of signal detection may be utilised to control an optical switch to re-route optical signals and generate alarm signals. The use of such detection in all optical networks avoids the requirement for electronic processing at the bit rate as a means of detection of loss of signal.