Abstract: A receiver architecture for receiving an FSK signal having a predetermined number of modulation levels includes a selectivity filter (206) for selectively passing a wanted channel and rejecting unwanted channels. The selectivity filter has a filter bandwidth of about one-half the bandwidth of a pre-modulation filter in a transmitter sending the FSK signal. A discriminator (208) is coupled to the selectivity filter for demodulating the signal. A symbol recovery processor (210) is coupled to the discriminator for recovering the symbols through a maximum likelihood sequence estimation (MLSE) technique utilizing N states for each symbol time, wherein N equals the predetermined number of modulation levels, and wherein templates used in the MLSE for symbol transitions are optimized with a bandwidth substantially less than the bandwidth of the pre-modulation filter.

Abstract: An electronic device that can receive an AM radio broadcast signal and has a switching power supply circuit, wherein a switching frequency of the switching power supply circuit is detected and a reception frequency of the AM radio broadcast signal is detected, and when a frequency as an integral multiple of the switching frequency falls within a reception frequency range of the AM radio broadcast signal, a load is added to the switching power supply circuit, whereby the switching frequency is changed.

Abstract: The invention proposes an LNB using two transposition frequencies chosen on either side of the reception band so as to obtain a transposition of supradyne type and a transposition of infradyne type according to the frequency used. This choice of transposition frequencies makes it possible to have an overlap zone in the middle of the reception band which is transposed with the aid of the two oscillation frequencies but at different frequencies. This makes it possible to choose between the two transpositions in the case where the frequency transposed with the aid of an oscillator corresponds to a particularly noisy frequency.

Abstract: A plurality of phases of sniff operations are performed for detecting wake-up signals being received by an implantable medical device (IMD), including a phase that performs a staged detection of whether the integrated frequency deviation of a received signal is outside of an expected frequency deviation range, where sniff operations are aborted if the integrated frequency deviation of the received signal falls outside of corresponding high and low thresholds in any stage, wherein the difference between the high and low thresholds tightens with each subsequent stage and an average frequency deviation over all completed stages are used in the calculations. One phase of sniff operations includes a dual frequency modulation (FM) detector including a first FM detector that introduces a small delay in a received signal providing an average frequency estimate and a second FM detector having a larger delay that is adjusted based on the estimated average frequency.

Abstract: A system to monitor gain in a broadband radio frequency transport system that includes a radio frequency antenna, a remote unit, and a host unit adapted to receive a signal from the remote unit over a transmission link. The remote unit includes a pilot tone generator adapted to generate at least one single-frequency tone having a known power level, a summing circuit operably associated with the pilot tone generator adapted to sum the single-frequency tone with the respective received radio frequency signal. Each host unit includes a pilot tone receiver circuit to receive the transmitted signal and detect the single-frequency tone transmitted over the transmission link. The host unit includes a controller to determine a gain within the transmission link and to determine if the gain is in a preset range of gains based on the power level of the received pilot tone.

Abstract: The invention relates to a method for determining the strength of a signal (18) at the input of a tuner (1a.) In this, the frequency-dependent amplification characteristic for the tuner is measured and stored in a memory assigned to the tuner. With the help of this characteristic the frequency-dependent variation of the amplification can be compensated during tuner operation, in order that the input signal strength can be deduced more precisely. For a tuner with automatic gain control (AGC), the frequency dependence of the AGC can also be recorded and stored in the memory by representative characteristics. The consideration of the AGC characteristics results in a further improvement to the precision of estimation of the input signal strength.

Abstract: Rejection of local oscillator harmonic response is provided in a mixing circuit with a pair of harmonic gating switches serially connected to the outputs of a balanced differential switching mixer and controlled by a gate clock signal having twice the frequency of a local oscillator signal controlling the switching mixer. An aperture or duty cycle of the gate clock signal determines which harmonic is rejected or suppressed, which is preferably a third and/or fifth harmonic since response of the balanced differential switching mixer to even harmonics is negligible. The resulting simple, efficient circuit is readily integrated directly into a phase-alternating mixer structure for a chopper-direct-conversion radio.

Abstract: A high-frequency amplifier includes first and second amplifying stages disposed in parallel for amplifying VHF/UHF television signals. The first amplifying stage includes a first FET and a second FET of a grounded-gate type connected in series between a common input terminal and a first output terminal to which a VHF-signal selection circuit is connected, and the second amplifying stage includes a third FET and a fourth FET of a grounded-gate type connected in series between the common input terminal and a second output terminal to which a UHF-signal selection circuit is connected. Switching between amplifying operations of the first and second amplifying stages is performed by an operation switching unit selectively setting one of the first and third FETs in a forward-bias state and the other in a reverse-bias state in response to a switching voltage externally set.

Abstract: A mobile phone with wireless camera detection. A mobile phone converts the frequency band of a received signal to mobile signal frequency band (for example GSM, DSC or PCS) with added mixer, oscillator, and filter. The converted signal is treated as a mobile signal prior to processing in the base band processor. Detected signal strength is checked to determine whether a wireless camera is currently present.

Abstract: A method and system for controlling an output signal power level of a wireless transmitter can be created by detecting the signal power level of the transmitter with a detector, selectively attenuating the output signal power level with an attenuator having variable attenuation levels, and monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold with a processor. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetermined threshold.

Abstract: A receiver architecture for receiving an FSK signal having a predetermined number of modulation levels includes a selectivity filter (206) for selectively passing a wanted channel and rejecting unwanted channels. The selectivity filter has a filter bandwidth of about one-half the bandwidth of a pre-modulation filter in a transmitter sending the FSK signal. A discriminator (208) is coupled to the selectivity filter for demodulating the signal. A symbol recovery processor (210) is coupled to the discriminator for recovering the symbols through a maximum likelihood sequence estimation (MLSE) technique utilizing N states for each symbol time, wherein N equals the predetermined number of modulation levels, and wherein templates used in the MLSE for symbol transitions are optimized with a bandwidth substantially less than the bandwidth of the pre-modulation filter.

Abstract: A signal transmission arrangement includes a signal transmitter and a signal receiver wirelessly communicating with the signal transmitter. The signal transmitter includes a hybrid signal device to hybridize the audio signal with the control signal to form a consolidating signal, a frequency modulator to high-frequency modulate the consolidating signal, wherein the consolidating signal is amplified and sent to the signal receiver in a wireless manner. The signal receiver includes a frequency demodulator to demodulate the consolidating signal and a signal dissociating unit to dissociate the consolidating signal to restore the audio signal and the control signal. Therefore, the signal transmission arrangement provides a low-bit rate coding transmission in control signals, in lieu of the high-bit rate coding transmission which requires the expensive high performance integrated circuit, so as to ensure the quality of the audio signal while being cost effective.

Abstract: Rejection of local oscillator harmonic response is provided in a mixing circuit with a pair of harmonic gating switches serially connected to the outputs of a balanced differential switching mixer and controlled by a gate clock signal having twice the frequency of a local oscillator signal controlling the switching mixer. An aperture or duty cycle of the gate clock signal determines which harmonic is rejected or suppressed, which is preferably a third and/or fifth harmonic since response of the balanced differential switching mixer to even harmonics is negligible. The resulting simple, efficient circuit is readily integrated directly into a phase-alternating mixer structure for a chopper-direct-conversion radio.

Abstract: A terminal for generating an electromagnetic field adapted to communicating with at least one transponder, and a method for controlling such a terminal including: an oscillating circuit adapted to being excited by a remote supply signal of the transponder; a phase demodulator for detecting possible data transmitted by the transponder; circuitry for regulating the signal phase in the terminal's oscillating circuit on a reference value; circuitry for measuring variables linked to the current in the oscillating circuit and to the voltage thereacross; and circuitry for comparing current values of these variables with predetermined values, to determine the presence of a transponder.

Abstract: The invention relates to detecting a narrowband signals from received signals. According to the different aspects of the invention, a sample set is first formed from received signals, whereby elements of the sample set represent their absolute values, and a lower reference value and an upper reference value are determined. Then adjacent samples exceeding the lower reference value are grouped in the same cluster. The purpose of the clustering is to group signals possibly originating from the same source together. Then, if at least one of these clustered samples exceeds also the upper reference value, it is most probable that the cluster is caused by a narrowband signal. The order of the determination steps can be varied according to the different aspects of the invention.

Abstract: A device and method are disclosed, whereby the normally complicated and difficult frequency determination is achieved by simply arranged and executed measures, namely by means of larger, smaller and/or equal comparisons and a counting of certain events. The invention further relates to arrangements whereby the noise signal level, or the influence thereof on the verification to be carried out is reduced.

Abstract: A stationary device 20 sends a portable-device finding signal to a portable device 10 from a plurality of stationary-device side antennae 24 and 25, which are located at different positions. Upon receipt of the portable-device finding signal from the stationary device 20, the portable device 10 sends a reception intensity data signal to the stationary device 20. The stationary device 20 determines the current position of the portable device 10 by using reception intensity data of the portable-device finding signals, which are received at the stationary-device side antennae, from the portable device 10.

Abstract: An RF receiver comprising a radio-frequency (RF) down-converter for receiving and down-converting an input RF signal to a lower frequency analog signal (e.g., an IF signal or baseband signal) and analog processing circuitry for receiving the lower frequency analog signal from the RF down-converter and outputting a processed analog signal. The processed analog signal includes a DC-offset signal introduced by the RF down-converter and the analog processing circuitry. The RF receiver also comprises an ADC circuit for converting the processed analog signal to a sequence of digital samples and a DC-offset correction circuit for detecting the DC-offset signal in a digital output signal of the RF receiver. The DC-offset correction circuit adds a DC-offset correction signal to the lower frequency analog signal. Adding the DC-offset correction signal to the lower frequency analog signal reduces the DC-offset signal in the processed analog signal at the analog processing circuitry output.

Abstract: A method is disclosed for operating a RF receiver of a communications equipment, as is circuitry for implementing the method. The method includes, while operating under the control of a data processor of the communications equipment, generating a calibration signal; injecting the calibration signal into a low noise amplifier (LNA) of the RF receiver; measuring a downconverted response of the receiver at a plurality of different frequencies of the calibration signal, or measuring the downconverted response of the receiver at a plurality of different LNA tuning combinations using a fixed calibration frequency, and at least one of tuning a resonance frequency of at least one LNA resonator based on the measured downconverted response so as to compensate at least for variations in component values that comprise the at least one resonator, or adjusting the linearity of the receiver.

Abstract: A time division duplex (TDD) single sideband (SSB) transceiver includes a transmitter adapted to input an analog audio signal, sample the analog audio signal, and to output an SSB frequency shift keyed (FSK) signal corresponding to the analog audio signal, the SSB FSK signal including analog information. A receiver is adapted to switch between receiving one of an upper sideband and a lower sideband of an external SSB signal.

Abstract: A band edge amplitude reduction system changes the filtering characteristics of a receiver based on the amplitude of signal(s) adjacent to an edge of the operating band of the receiver and/or of signals not under the power control of the receiver. For example, the receiver measures the power level over a bandwidth at the band edges of the operating band of the receiver. If the signals adjacent to the operating band are strong enough relative to the signal power within the operating band, overload protection circuitry changes the filtering characteristics of the receiver to improve the attenuation of the signal(s) from the adjacent band(s). In certain embodiments, the overload protection circuitry switches in filter(s) with a narrower bandwidth to attenuate the signal(s) from adjacent band(s) at the edge(s) of the operating band of the receiver, thereby preventing interference with or the overload of the receiver by signals from outside the operating band and/or not under the power control of the receiver.

Abstract: A method and system for controlling an output signal power level of a wireless transmitter can be created by detecting the signal power level of the transmitter with a detector, selectively attenuating the output signal power level with an attenuator having variable attenuation levels, and monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold with a processor. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetermined threshold.

Abstract: A terminal for generating an electromagnetic field adapted to communicating with at least one transponder, and a method for controlling such a terminal including: an oscillating circuit adapted to being excited by a remote supply signal of the transponder; a phase demodulator for detecting possible data transmitted by the transponder; circuitry for regulating the signal phase in the terminal's oscillating circuit on a reference value; circuitry for measuring variables linked to the current in the oscillating circuit and to the voltage thereacross; and circuitry for comparing current values of these variables with predetermined values, to determine the presence of a transponder.

Abstract: The system controller 12 attains program table data from a received electric wave upon turning on the power source. Program table data are rearranged for every ensemble and stored again. The user makes an input operation to set a channel-feed selection which requires switching of a program to be attained. Then, the system controller 12 performs a processing of attaining a program listed next in the same ensemble as that of the program which has been attained just before based on the rearranged program table data. When attaining a program next to a program listed in the last, the ensemble is switched to another ensemble. Programs are attained sequentially from the program listed first in the another ensemble thus switched. Switching to a different ensemble takes place at a reduced frequency, so that the time until output of an attained program can be shortened.

Abstract: A method for recording information that is transmitted over a radio frequency, especially traffic information, in which, in a monitoring state, the receiving device is supplied with power in a clocked manner. While switched on, the receiving device is tuned to a preestablished radio frequency and the received radio frequency is monitored for the presence of an identifier designating information. In the event an information identifier is detected, the receiver is supplied with power for the duration of the identifier and the information is recorded. In response to switching on the monitoring state, the preestablished radio frequency is determined as the frequency to which a radio frequency refers that transmits no information and that was set before the monitoring state was switched on.

Abstract: A tone generator in a transceiver of a communications device may generate an arbitrary signal using two shift registers to generate the time intervals. During each time interval, a different capacitor is switched onto the node to change the voltage potential on that node. The amplitude of the waveform during each time interval is changed to provide the desired tone.

Abstract: A cellular communications system may include one or more cellular base stations and a plurality of mobile cellular communications devices for communicating therewith. More particularly, the cellular base station and the mobile cellular communications devices may each include an encoder for generating an information signal. Furthermore, a modulator may generate a modulated waveform based upon the information signal, a carrier signal having a frequency and phase associated therewith, and at least one carrier phase reference symbol. The modulator may also include an offset circuit so that the modulated waveform includes a carrier frequency indicator. A transmitter may also be included for transmitting the modulated waveform to the desired cellular base station or mobile cellular communications device.

Abstract: Transitory audio information that is subject to interruption is provided without loss of content. Transitory audio information received from an audio source is audibly provided until an interrupt signal is received. The transitory audio information is buffered while a message associated with the interrupt signal is audibly provided. Upon conclusion of the message, the buffered transitory audio information is audibly provided.

Abstract: A resonant tunneling diode or diode array oscillator (10) including a resonant diode (11) is coupled to a millimeter-wave source (14) and a quench generator (16) for periodically quenching the oscillations so that the average oscillation time of the oscillator is proportional to signal strength of the source (14). The signal source can be from an antenna such as a dipole or tapered slot line antenna.

Abstract: A receiver capable of receiving a plurality of different codes at a plurality of different frequencies is set forth herein. The receiver offers digital frequency control by using a controller driven signal diode to add or remove capacitance to or from a band pass filter circuit, thereby altering the frequency the bandpass filter is setup to receive. Input devices allow the receiver code, bit pattern, and relay output to be selected among a plurality of different codes, bit patterns, and relay output types. The receiver processes the selections, determines what frequency receiver actuation signal is to be received, and alters the bias of the signal diode to adjust the bandpass filter frequency accordingly.

Abstract: 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.

Abstract: Provided is a microwave detector including a resistive mixer that uses a field effect transistor (FET) for generating an intermediate frequency signal by combining a signal generated by an antenna and an output of a local oscillator. The microwave detector includes an antenna for receiving a radio signal; a modulator for modulating the radio signal by converting its frequency with a resistive mixer that uses one or a plurality of FET; a central processing unit for identifying the modulated signal and its frequency band, measuring the intensity of the signal, and outputting the same as a predetermined signal; and a display unit for outputting a visual or audio signal in response to the signal generated by the central processing unit, and selecting a mode of the output of a signal. The microwave detector including an FET is easy to make at a lower cost, hardly malfunctions, and further can operate with a little power.

Abstract: A call progress analysis system is provided which is generic to any telecommunications system with which it is used due to configurable detection parameters. A signal on a channel of the telecommunications system is detected in intervals of changing frequency composition and compared to stored pattern descriptors, each of which defines a different call progress signal. In an alternative embodiment of the invention, a frequency mask is computed that is specific to a user-defined call progress analysis class. This frequency mask is used to make the DSP receiver ignore frequencies that are not part of any call progress pattern in a particular class. The frequency mask can be used in a frequency detection mode or an energy detection mode. In either mode, the detector can be customized for each channel.

Abstract: A method and system for improved detection of analog signals, where the analog signals may be composed of one or more analog frequencies. In the method and system, an analog signal is received. A stream of data samples is created from the analog signal. Based on the stream of data samples, a confidence factor regarding the presence of the one or more analog signals is created. The confidence factor is created based upon a confidence factor calculated for each of the one or more analog frequency signals. The confidence factor calculated for each of the one or more analog frequency signals is calculated utilizing incremental energies associated with each of the one or more analog frequency signals.

Abstract: A receiver for broadcast signals, e.g. DAB, FM, DVB, and digital or analog short-wave RF broadcast signals according to the present invention includes a polyfunctional circuit (5) that can be switched into three modes and performs the digital frequency demodulation which is needed for the reception of a frequency modulated signal in a first mode A, a digital frequency adjustment of the receiver in case of the reception of a digital or analog modulated broadcast signal like DAB, DVB, DRM or AM in a second mode B and the digital frequency adjustment and the digital gain control of the receiver which is needed in case of the reception of a digitally modulated broadcast signal like DAB, DVB, DRM in a third mode C. Depending on the needed functionality not all of these modes need to be realized. Nevertheless, the same hardware will be used for different purposes although the circuit is realized with an optimized amount of hardware to realize an efficient receiver.

Abstract: An information processor, a method of information processing and a program storing medium that ensure radio data communication by further accurately showing wave condition to a user. A field intensity level showing screen to be displayed in plural levels that is finer than a portable communication terminal unit is generated based on a field intensity signal showing the field intensity level of the portable communication terminal unit that will be supplied via connecting means connected to the portable communication terminal unit, and the above field intensity level showing screen is displayed on display means. Thereby, the user can further correctly recognize the communicating condition of the portable communication terminal unit. Thus, if the user performs data communication when the wave condition is stable, the data communication can be surely executed in the stable communication environment in which the line is never disconnected.

Abstract: Determination and processing for fractional-N programming values. The present invention is operable to receive a clock signal (CLK) and to transform that CLK into a new CLK, when necessary, for use by various circuitries within a system. The present invention is operable to generate two different CLKs for use by a radio frequency (RF) circuitry and a baseband processing circuitry in certain embodiments. The present invention employs a measurement circuitry and to characterize a first CLK and uses a fractional-N synthesizer to perform any necessary processing to generate the one or more CLKs to the other CLKs within the system. The first CLK may be received from an external source or it may be generated internally; in either case, the present invention is able to modify the CLK into another CLK for use by other circuitries within the system or for use by another external device.

Abstract: A radar detector includes an antenna for receiving a first signal of ultrahigh-frequency, a first local oscillator oscillating a second signal, a first filter removing noise from the second signal oscillated via the first local oscillator, a first mixer mixing the first signal of ultrahigh-frequency with a third signal filtered via the first filter, an intermediate frequency amplifier amplifying a fourth signal mixed at the first mixer, a second local oscillator oscillating a fifth signal, a second mixer mixing a sixth signal amplified via the intermediate frequency amplifier with the fifth signal oscillated by the second local oscillator, a second filter filtering a seventh signal mixed at the second mixer, a demodulator converting analog values of an eighth signal filtered by the second filter into digital values, a memory part storing data of relations between a ninth signal converted via the demodulator and the second and fifth signals oscillated by the first and second local oscillators, a central proces

Abstract: 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.

Abstract: A receiver architecture includes a selectivity filter (206) for selectively passing a wanted channel and rejecting unwanted channels. The selectivity filter has a filter BT of about one-half the BT of the transmitter filter. A discriminator (208) is coupled to the selectivity filter for converting received symbols from the frequency domain to the time domain symbols. A symbol recovery processor (210) is coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.

Abstract: The Vehicle Sound and Alerting System is generally comprised of a conventional automobile stereo system that has police radar detection capabilities. When police radar is detected, the stereo's volume is immediately muted. An audible alert is then outputted through the vehicle's speaker system or a built-in speaker on the control panel, or a combination of both, depending on how the driver has it configured. A visual alert is also produced on the control panel, which displays the band of radar that was encountered, and its relative signal strength. The radar detector receives signals from the vehicle's antenna and an auxiliary antenna. The auxiliary antenna is attached to the vehicle's grille. This improves the signal reception ability.

Abstract: In a receiver, either an FM/AM signal to be used for a keyless entry system or a high frequency signal to be used for an automobile audio system for FM broadcast is applied to a first converter. An IF limiter amplifier amplifies the output signal of the converter and subsequently limits the amplitude of the output signal to a predetermined level. An FM detector circuit FM-detects the output signal of the IF limiter amplifier. A stereophonic demodulation circuit demodulates the output signal of the detector circuit. A high frequency signal for AM broadcast is fed to an IF amplifier by way of a second converter. Either the output signal of the IF limiter amplifier or that of the IF amplifier is applied to an AM detector circuit.

Abstract: This invention intends to provide a tone signal detection circuit that accurately detects a tone signal regardless of a reception electric field strength. To accomplish this object, the tone signal detection circuit according to the invention is comprised of a first filter that extracts a signal of a specific frequency from an input signal, a second filter that excludes the signal of the specific frequency from the input signal and extracts signals of frequencies near the specific frequency, a subtractor that subtracts an output of the second filter from an output of the first filter, and a judgment circuit to judge whether the tone signal is present or not in the input signal on the basis of an output from the subtractor.

Abstract: In a receiver, either an FM/AM signal to be used for a keyless entry system or a high frequency signal to be used for an automobile audio system for FM broadcast is applied to a first converter. An IF limiter amplifier amplifies the output signal of the converter and subsequently limits the amplitude of the output signal to a predetermined level. An FM detector circuit FM-detects the output signal of the IF limiter amplifier. A stereophonic demodulation circuit demodulates the output signal of the detector circuit. A high frequency signal for AM broadcast is fed to an IF amplifier by way of a second converter. Either the output signal of the IF limiter amplifier or that of the IF amplifier is applied to an AM detector circuit.

Abstract: A severe weather detection apparatus for detecting severe weather and method of detecting and warning of approaching severe weather conditions is provided. The severe weather detector apparatus includes a barometric pressure sensor and computerized means for calculating the rate of change in the barometric pressure. By monitoring and deriving a value representative of the rate of change in the barometric pressure over time, a threshold is established and compared to the current rate of change in the barometric pressure. The derived rate of change is compared to a value stored in the device which reflects approaching severe weather conditions. Rates of change which may indicate the approach of severe weather activate a voice-enunciated alarm that announces the potentially dangerous barometric activity. The severe weather detection apparatus is portable and suitable for battery power and installation in the same manner as a home smoke alarm or carbon monoxide detector.

Abstract: A radio for a half-duplex communication system includes a warning circuit for indicating when a transmission of a signal is taking place. The radio includes a transceiver for providing a voice signal, and the warning circuit includes a pulse generator for providing a beacon signal. The voice signal and the beacon signal are combined into a transmitted signal. The warning circuit includes a power splitter for receiving a remote signal from an antenna and for dividing the remote signal into the voice and beacon signals thereof. The power splitter then provides the voice signal to the transceiver. A comparator compares a level of the received beacon signal with a reference and provides an output to an indicator (such as an LED) when the level of the beacon signal is greater than the reference. As such, the indicator illuminates in the presence of a beacon signal.

Abstract: A weather alert system to warn a user when an emergency signal has been broadcast and to simultaneously activate a television or other visual information source and to select a predetermined informational channel. The weather alert system includes a signal detector for detecting a broadcast alarm signal and for generating an activation signal upon detection of the alarm signal. A remote controller is operatively connected to the signal detector for producing a remote control signal in response to said activation signal. The remote control signal is utilized to trigger the activation of a visual information source such as a television or a computer to provide visual information relating to the hazardous condition.

Abstract: A novel frequency scheme for a police radar detector enables improved sweeping of the X, K, Ku and Ka radar bands. The novel frequency scheme requires two initial frequency conversions for detection of the X, K and Ka radar bands and a single initial frequency conversion for the Ku radar band with single initial frequency conversion being enabled by disabling the second mixer. During sweeping of the X, K and Ka bands, selectable, i.e., upper or lower, sideband suppression is employed to reduce undesired image sidebands and noise prior to the second frequency conversion. In addition, noise at the second IF frequency is reduced to prevent this noise from feeding through the second mixer into the second IF amplifier. During the Ku band sweep, the second mixer is bypassed and shunting of signals at the second IF frequency is disabled so that these signals enter the second IF amplifier.

Abstract: A multi-band microwave detector includes an antenna, a plurality of reception systems connected to the antenna in a parallel arrangement, a judgement circuit for judging whether or not a microwave signal detected by the reception systems is a detection target microwave signal, an alarm circuit for outputting an alarm when the judgement circuit judges the detected microwave signal to be a detection target microwave signal, wherein each reception system is constructed from a superheterodyne reception circuit having a prescribed intermediate frequency that is mutually different from the intermediate frequencies of all the other reception systems, and wherein all the reception systems are operated simultaneously during one detection cycle.

Abstract: A radar detector is comprised of a voltage controlling oscillator (VCO) instead of DROs, thereby decreasing the cost of radar detector. The radar detector comprises a voltage controlled 1st local oscillator generates a signal of a frequency of 11.2796 GHz to 11.9832 Ghz, two (2) 2nd local oscillators generate signals with frequencies of 0.603 GHz and 1.3668 GHz, a memory section which stores pair combination data indicating the relation between the frequency of said voltage controlled oscillator, the frequencies of said local oscillators and the frequency of the received radar signal in advance; and a controlling section which decides the frequency of a radar signal by comparing the obtained information with said pair combination data.