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| Number | Title | Issue Date |
| 7256920 | Electro-optic modulator A modulator circuit (28) for directing a voltage across a modulator element (26) to modulate a beam (20) includes a first inductor L1 that is electrically connected in parallel to the modulator element (26) and a second inductor L | 08/14/2007 |
| 7215227 | Gm-C filter compensation Compensation of effects derived from bandwidth limitations of an active frequency-selective circuit is effected by appropriately coupling a resistance to the frequency-selective circuit. In one embodiment, the resistance is designed to have a value that is inversely... | 05/08/2007 |
| 7116963 | Simplified high frequency tuner and tuning method A disclosed method tunes a signal from a channelized spectrum having a predetermined channel spacing. A signal of interest having a predetermined maximum bandwidth is mixed with a local oscillator signal, which has a frequency that is an integer multiple of the chan... | 10/03/2006 |
| 7102329 | Method of measuring the battery level in a mobile telephone Measuring the voltage level of a mobile telephone battery during a charging operation involves disabling the charge temporarily so that the battery rapidly enters discharge mode. The discharge mode voltage is more representative of the true battery charge level, so ... | 09/05/2006 |
| 7095801 | Phase adjustable polyphase filters A polyphase filter for wireless communication systems includes at least two phase splitting filters each having a variable resistance across their respective outputs. The variable resistance can take any suitable form, such as a MOS transistor biased in the linear (... | 08/22/2006 |
| 7019586 | High-speed Gm-C tuning A technique to achieve high-speed tuning of a Gm-C circuit, such as, for example, a Gm-C filter. In one embodiment, a master Gm-C time-constant circuit incorporates at least one element (either a transconductance or a capacitance) that is matched to a corresponding ... | 03/28/2006 |
| 7006562 | Phase demodulator, phase difference detector, and interferometric system using the phase difference detector A phase demodulator is used for measuring a phase difference between a phase-modulated test signal and a phase-modulated reference signal having fixed carrier frequencies. The phase demodulator includes an amplitude control device for adjusting amplitudes of the tes... | 02/28/2006 |
| 6972617 | FM demodulator including a DC offset detector An FM demodulator has a differential output demodulator for receiving an FM signal and for outputting a positive differential signal and a negative differential signal of a demodulated signal of the FM signal, a DC offset detector electrically connected to the diffe... | 12/06/2005 |
| 6909270 | Phase detector capable of detecting an accumulated value of phase displacement at a high speed and frequency stability measuring apparatus for arbitrary nominal frequency using the same A phase region detector receives in-phase signal I representing in-phase component and quadrature signal Q representing quadrature component of a first signal and second signal respectively, equally divides an angle range of 2 π into a plurality M of three or more ... | 06/21/2005 |
| 6621879 | Digital radio system, a digital radio device, and a quadrature demodulator A digital radio device having a quadrature demodulator that does not suffer from substantial amplitude roll-off at the relevant operating range. Such a device is obtained by a phase shifting network in a quadrature branch of the demodulator having a serie... | 09/16/2003 |
| 6335659 | Demodulator circuits A frequency modulated signal demodulator circuit includes a phase shift element and a time delay element which operate on an input signal (V_IF). The phase shift element and the time delay element are provided by a gyrator component (14, 16, 20).... | 01/01/2002 |
| 6020784 | FM demodulation circuit An FM demodulation circuit includes a phase conversion circuit which converts a frequency variation of an input signal into a phase variation and has a variable conversion characteristic, and a control current source circuit which outputs, when the level ... | 02/01/2000 |
| 5929716 | High performance voltage controlled oscillator that is cost efficient A high-performance voltage controlled oscillator without use of variable capacitance (varicap) diodes which is easy in fabrication in an semiconductor IC form. The voltage controlled oscillator includes:a differential amplifier having a differential pair ... | 07/27/1999 |
| 5793251 | Demodulator circuit using gyrator circuit A demodulator circuit includes a gyrator circuit forming a derived equivalent inductance which is used in a demodulating circuit. The gyrator circuit has a first operational transconductance amplifier and a second operational transconductance amplifier, w... | 08/11/1998 |
| 5596298 | Bus aligned quadrature FM detector In a quadrature FM detector, demodulation is performed by a product detector which multiplies an amplitude limited FM modulated information signal by a version of the amplitude limited FM modulated information signal which has been phase shifted by a phas... | 01/21/1997 |
| 5572164 | FM demodulator with threshold extension and receiver comprising such an FM demodulator An FM demodulator having two input terminals (11, 12), to which FM input signals having 90° phase relation are applied, the said FM demodulator including a phase comparator (1) and a tunable, phase shifting circuit (2), the phase shifting circuit (2) bei... | 11/05/1996 |
| 5453714 | Binary FM demodulator with self-adjusting resonant operating frequency according to demodulated binary output signal duty cycle A demodulator for demodulating a binary frequency-modulated signal includes a demodulator with a quadrature tank circuit and a duty cycle monitor circuit. The quadrature tank circuit has a voltage-controllable resonant frequency for compensating for shift... | 09/26/1995 |
| 5450033 | Frequency demodulation circuit A frequency demodulation circuit having an improved detection sensitivity is provided by forming an all-pass equalizer in a Quadrature-type demodulator capable of allowing a band covering at least a carrier frequency deviation to pass therethrough. The eq... | 09/12/1995 |
| 5428404 | Apparatus for method for selectively demodulating and remodulating alternate channels of a television broadcast An apparatus and method for demodulating and remodulating a transmitted signal prior to presentation to a television receiver, the transmitted signal comprising a video signal, a first channel signal, and a second channel signal, wherein one of the two ch... | 06/27/1995 |
| 5414385 | Dual mode FM quadrature detector A dual mode quadrature detector (15) uses the same components for both narrow band and wide band operation and provides an output amplitude which is independent of the mode of operation selected. A multiplier (32) provides a demodulated output signal (16)... | 05/09/1995 |
| 5341107 | FM quadrature demodulator with two phase comparison circuits FM quadrature demodulator having in-phase and quadrature terminals for applying a pair of FM-modulated signals in a mutual phase quadrature thereto, having a modulation signal which is frequency-modulated on a carrier, one of the two terminals being coupl... | 08/23/1994 |
| 5333151 | High speed frequency-shift keying decoder A frequency-shift keying (FSK) signal detector splits an FSK signal into two paths. In one path, a phase-altering circuit having a variable frequency characteristic between the two encoding frequencies of the FSK signal provides either a phase lead or a p... | 07/26/1994 |
| 5293135 | FM demodulator with self-tuning quadrature detector A quadrature detector FM demodulates an intercarrier signal operating at an unknown frequency. An LC tank circuit develops a 90° phase shift across inputs of a multiplier. The output signal of the multiplier is amplified and fedback to control a reactanc... | 03/08/1994 |
| 5204635 | Digital FM demodulator utilizing uncorrelated clock reference signals An FM demodulator which generates a modulated object signal directly in digital form, wherein an input FM signal is phase detected, then converted to digital form, then quantized into a pulse density modulated binary signal using a clock reference signal ... | 04/20/1993 |
| 5166633 | Angle modulation dectector An angle modulation detector which prevents a demodulated output from being influenced by fluctuations in the amplitudes of signals generated from angle-modulated signal sources such as a phase-modulated signal and a frequency-modulated signal, even if th... | 11/24/1992 |
| 5136254 | FM demodulator circuit whose demodulation output is decreased in distortion A differential amplifier amplifies an FM signal supplied from an FM signal source. A phase shift circuit shifts a phase of a carrier signal included in an FM signal output from the differential amplifier. A multiplier circuit multiplies an FM signal suppl... | 08/04/1992 |
| 5053717 | FSK demodulator An improved multilevel FSK demodulator, according to the invention, is provided that down-converts the IF frequency back to baseband quadrature via dual mixers. The improved multilevel FSK demodulator uses controllable time-delay in the demodulation proce... | 10/01/1991 |
| 5015961 | Frequency shift demodulator The invention improves the ability of the FS demodulator-circuit of an FS digital transmission system so as to withstand noise with low error count. The invention uses two different types of all pass networks and a phase measuring circuit to average rando... | 05/14/1991 |
| 4926132 | FM detector with reduced distortion An FM detection circuit utilizes a first multiplier and phase shift circuit to demodulate an FM signal. The output signal also contains harmonic distortion as a result of the demodulation process. A gain control circuit is included to provide a first gain... | 05/15/1990 |
| 4618829 | Bridge circuit demodulator A bridge circuit demodulator for frequency-modulated signals includes a parallel resonant circuit tuned to the carrier frequency of the FM signals. The resonant circuit includes the secondary winding of a transformer which is strongly coupled to the secon... | 10/21/1986 |
| 4616186 | FM quadrature demodulator with distortion compensation A circuit for reducing the distortion in an FM quadrature demodulator. A non-linear circuit stage is connected after the quadrature demodulator, whose characteristic has an inverse curve form like the demodulator characteristic. If the FM quadrature demod... | 10/07/1986 |
| 4612510 | FM demodulator using combined outputs of plural FM detectors An FM detection apparatus comprising a frequency dividing means, having a division ratio N, arranged to receive an incoming radio frequency (RF) signal carrying frequency modulation and to frequency divide the RF signal to provide a plurality of frequency... | 09/16/1986 |
| 4608538 | FM quadrature detector with ferrite bead tuned circuit A quadrature detector circuit for demodulating frequency modulated information is provided that is particularly designed for use in television receive only (TVRO) satellite communication video receivers. The bandwidth restrictions of conventional quadratu... | 08/26/1986 |
| 4608539 | FM detector with injection locked divider input circuit A frequency modulation detection arrangement comprises an FM detector and an injection-locked frequency divider arranged for receiving a radio signal and for providing a frequency divided radio signal in response thereto. The FM detector is coupled with t... | 08/26/1986 |
| 4603302 | Frequency modulation detectors An FM detector comprises a frequency divider arranged to frequency divide an input FM signal and a phase sensitive detector coupled to the frequency divider. The detector receives a first frequency divided signal from a first path and receives a second fr... | 07/29/1986 |
| 4560943 | F.M. demodulator with fail-safe features An F.M. demodulator of the phase quadrature type is adapted for fail-safe operation and in particular for use in a railway signalling system. A Bessel band-pass filter is chosen for the design basis of the phase delay arm, its characteristics, failure mod... | 12/24/1985 |
| 4535296 | FM-Demodulator with ladder filter delay line and multiplier For demodulating an FM-carrier which is, for example, modulated by a video signal and two sound subcarriers, a Gilbert mulitplier (13) and a phase shifting circuit (12) are used. The phase shifting circuit is formed by elements of a Gaussian type bandpass... | 08/13/1985 |
| 4490680 | Integrable quadrature FM demodulator using fewer signal pins A quadrature type FM demodulator device used, for example, in a television receiver, includes a band pass filter for filtering a sound intermediate frequency (SIF) signal input to the device. The output of the band pass filter is coupled through a filter ... | 12/25/1984 |
| 4463317 | FM demodulator with regulation of the output D.C. component A frequency modulation detector, includes an FM (frequency modulation) demodulator, an adder responsive to first and second signals for maintaining a constant D.C. level output signal, the first signal being the FM signal, and a feedback circuit connected... | 07/31/1984 |
| 4441079 | Multiple bandwidth FM demodulator A multiple bandwidth quadrature type FM demodulator employs a double-balanced mixer supplied with a frequency modulated IF signal directly and through one of a selectable plurality of bandpass circuits each having a different bandwidth, having a linear ph... | 04/03/1984 |
