191results about "Heterodyning/beat-frequency comparison" patented technology

A method of testing an electronic device includes measuring radio frequency emissions at a plurality of positions relative to a trusted unit of a particular electronicdevice during operation of the trusted unit, and measuring radio frequency emissions at the same plurality of positions relative to a second unit of the particular electronic device. For each of the plurality of positions, the radio frequency emissions measured from the second unit are compared to the radio frequency emissions measured from the trusted unit. The method then determines whether there is any frequency at which the measured amplitude of the radio frequency emissions from the second unit and the measured amplitude of the radio frequency emissions from the trusted unit exhibit a statistically significant difference.

An electrical touch sensor is provided. The electrical touch sensor includes: a touch detection part having at least one touch pad and generating a first signal having a same delay time regardless of whether the object is in contact with the touch pad and a second signal having a varied delay time according to whether the object is in contact with the touch pad; and a contact signal generator generating a contact signal in response to the delay time-difference between the first and second signals. Therefore, it is possible to increase operation reliability by precisely determining whether the object is in contact with the pad, when the object has charge accumulation characteristics more than a certain level, although its conductive is insufficient. In addition, the electrical touch sensor can determine whether the object is in contact with the pad using only one pad to reduce a layout area of a product.

System and method for specifying a signal analysis function. First user input is received, e.g., to a graphical user interface (GUI), indicating a parameter for a first operation implementing at least a portion of the function. The first operation is programmatically included in a sweep loop. Second user input is received specifying a sweep configuration for a sweep on the parameter. The signal includes signal data, e.g., signal plot data or tabular data. The sweep configuration includes: a range of values for the indicated parameter, a number of iterations for the sweep, an interpolation type, step size for the sweep on the indicated parameter, specific values in the range of values for the parameter, source for at least some of the sweep configuration, and / or resultant data. The sweep is performed on the parameter per the sweep configuration, generating resultant data which is stored, and optionally displayed, e.g., in the GUI.

A spectrum analyzer is provided that includes components to achieve from below 9 kHz to above 20 GHz operation range while remaining hand-held. Components of the spectrum analyzer include an integrated precision stand-alone step attenuator that does not rely on printed circuit board (PCB) mounted circuit elements within the signal path. Further, a PIN diplexing switch separates signals into different base-band and highband paths. The baseband path includes a pre-amplifier for low frequency signals, while the higher frequency bands may not necessarily include a pre-amplifier. The baseband path further provides improved broadband termination of its 1st mixer IF port by incorporating a new quadrature-coupled directional (QCD) filter that includes a ring resonator. An inexpensive air dielectric multi-cavity baseband filter is also used to suppress 2nd mixer IF images. The highband path incorporates multi-throw MMIC PIN diode switches to selectively filter different bands of input signals. At least three total 1st mixers are used to increase operation bandwidth. A phase locked loop providing a 1st LO to the 1st mixers is created that uses a divide-by-two frequency divider in cascade with a sampler-type frequency downconverter. The output of the 1st LO is frequency doubled and filtered to increase the frequency range of the highband signal path.

This invention discloses one method and device to improve time zone signals frequency stability measurement, which comprises the following steps: reference time signals are processed through DDS technique to get stable and accurate circle signals; expending measurement frequency signals range to get better reference signals and signals to be tested at fine time measurement; using DDS unit to process measurement frequency signals; when circle sample time singles come, according to fine time measurement module minimum resolution rate to test signals to be tested with reference time signals minimum phase difference to make the meter work to fulfill frequency signal measurement.

The invention discloses a method for detecting zero crossing time, frequency and phase difference of power sinusoidal signals. In the method for detecting zero crossing time, by using the fundamental principle that a sinusoidal signal close to the zero crossing can be approximately equivalent to a linear signal, after a zero crossing position of a signal is worked out by rough calculation, a voltage amplitude close to the signal zero crossing is counted by the unary linear regression theory so as to acquire the zero crossing time of the sinusoidal signal. The method for detecting a frequency of a zero crossing point of a sinusoidal signal comprises the following steps of: obtaining a period value of each zero crossing point by carrying out the cumulative mean on each zero crossing point phase different of the obtained signal, and solving the reciprocal to obtain the signal frequency value. The method for detecting phase difference comprises the following step of calculating the phase difference between different signals by means of a zero crossing point phase value of each different signal. The invention is insensitive to the relative position of the zero crossing point of the actual signal, can realize higher detection accuracy in the digital detection system, has a strong suppression function to the noise of the signal source and the interference, and finally ensures the application of the method in a high-accuracy detection field.

A method and apparatus for limiting access to an integrated circuit (IC) upon detection of abnormal conditions is provided. At least one of abnormal voltage detection, abnormal temperature detection, and abnormal clock detection are provided with low power consumption. Both abnormally low and abnormally high parameter values (e.g. abnormally low or high voltage, temperature, or clock frequency) may be detected. Abnormal clock detection may also detect a stopped clock signal, including a clock signal stopped at a low logic level or at a high logic level. Furthermore, abnormal clock detection may detect an abnormal duty cycle of a clock signal. A sampled bandgap reference may be used to provide accurate voltage and current references while consuming a minimal amount of power. Upon detection of an abnormal parameter value, one or more tamper indications may be provided to initiate tampering countermeasures, such as limiting access to the IC.

An electrical circuit and method for measuring small variations in a high frequency signal is disclosed. The circuit generates a coarse measurement of the input signal frequency and a reference signal having the same frequency as the frequency represented by the coarse measurement. The circuit measures the difference in frequency between the input signal and the reference signal, and adds the coarse measurement and the difference measurement to determine the frequency of the input signal. The circuit may be used in conjunction with a piezoelectric acoustic wave device and oscillator to provide an apparatus for accurately measuring low concentrations of a gas.

A test circuit determines whether a frequency of an output clock signal of a clock circuit is above an output threshold frequency. An input clock signal of the clock circuit is set to an elevated frequency that is higher than a specified frequency. A first counter counts the number of clock cycles of the input clock signal in a test interval to within a tolerance of the elevated frequency. The tolerance of the elevated frequency is higher than a tolerance of the specified frequency. A second counter counts the number of clock cycles of a feedback clock signal in the test interval. A comparator determines whether the frequency of the output clock signal is above the output threshold frequency based on the number of clock cycles of the input clock signal and the number of clock cycles of the feedback clock signal.

A first instance and a second instance of an oscillating circuit are each formed as part of an integrated circuit and are used to monitor degradation over time of one or more portions of the integrated circuit. The first instance of the oscillating circuit is configured to be coupled to a power source during normal operation of the integrated circuit and the second instance is configured to be decoupled from the power source. Over the lifetime of the integrated circuit, the first instance undergoes degradation from use while the second instance of the oscillating circuit remains unpowered, therefore experiencing essentially no use-related degradation. During a testing operation, the second instance can be used as a reference circuit that accurately quantifies use-related degradation of the first instance of the oscillating circuit and, by extension, one or more portions of the integrated circuit.

Systems and other embodiments associated with synthetic instrumentation are presented. A reconfigurable synthetic instrumentation unit comprises an input module, with dual input / output ports and conditioning logic to condition an input signal. An RF down converter selectively down converts the conditioned input signal. A sampled RF down converter selectively samples the conditioned input signal. A pair of narrowband A / D converters are configured to convert one of the conditioned signal, the down converted signal and the sampled signal to produce a narrowband digital signal. A pair of broadband A / D converters convert at least one of the conditioned signal, the down converted signal and the sampled signal to produce a broadband digital signal. Signal processing logic selectively performs digital signal processing on the broadband digital signal or the narrow band digital signal.

A handheld Vector Network Analyzer (VNA) is provided with circuitry capable of providing operation over a very wide bandwidth. The VNA includes two reflectometers, a first high frequency reflectometer (150) such as the model S331 Site Master™ and a second lower frequency reflectometer (50) such as the model S820 Site Master™, both the S331 and S820 being manufactured by Anritsu Company of Morgan Hill Calif. The high frequency reflectometer (150) includes a forward coupler (109) having a coupling path connected to a high frequency impulse signal source (102), and a through path connecting the test port (3) and incident and reflected signal measurement couplers (110,112) to a load (107). To connect the high and low frequency reflectometers (150,50), a diplexer (170) is connected between the load (107) and an output of the low frequency reflectometer (50). The diplexer (170) includes an inductor (172) for blocking high frequency signals from the low frequency reflectometer (50), and a capacitor (174) preventing a low frequency signal path through the load (107) to ground while providing an impedance matching the load (107) to high frequency signals.

Testing is performed on a device under test. A first port of a first calibration module is connected to the device under test. A second port of the first calibration module is connected to a network analyzer. A first port of a second calibration module is connected to the device under test. A second port of the second calibration module is connected to the network analyzer. A measurement calibration and testing are performed without disconnecting the first port and the second port of the first calibration module and without disconnecting the first port and the second port of the second calibration module.

A ventricular shunt systems and methods of preventing hydrocephalus are described herein. In one aspect, the ventricular shunt system has at least one pressure sensor that is configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy and is variable in response to the pressure in a patient's ventricle.

The present invention provides a sensor system and a corresponding sensing method employing the sensor system. The sensor system comprises a sensor (12) having an input (20) and an output (22), a feedback path (16) from the output to the input, and a filter (14; 92) in the feedback path. The filter comprises a narrow band filter, which is tuned or tunable to a respective one of signals that are wanted signals and signals that represent interference signals. The sensor and the filter are arranged so as to alter the relative amplitudes of the wanted signals and the interference signals in order to increase the relative amplitude of the wanted signals and reduce the relative amplitude of the interference signals.

The invention discloses a frequency and phase difference precision measurement method based on frequency and phase relationship auxiliary processing. The frequency and phase difference precision measurement method comprises the following steps of: allowing a 10-MHz frequency scale output by a caesium clock to pass through a shaping circuit and an adjustable pulse generation circuit to generate a pulse signal; automatically synthesizing frequency f0 by using a digital display scope (DDS), wherein the value of the f0 depends on fx roughly measured by a singlechip microcomputer, so that the integer multiple of the group period of the fx and the f0 is equal to the time value of a gate and the value of the group phase quantum of the fx and the f0 is equal to the resolution ratio of a group phase coincidence detection circuit; transmitting the f0 and the fx to a pilot frequency phase coincidence detection circuit to generate the actual measurement gate; controlling work of a counter; calculating the value of the fx according to the counting result by using a microprogrammed control unit (MCU); and finally displaying output by using a liquid crystal display (LCD). According to the frequency and phase difference precision measurement method disclosed by the invention, one DDS is introduced to determine the frequency relationship between the fx and the f0, and a good measuring effect of any frequency signals within the required gate time is achieved.

A device to measure a passive intermodulation (PIM) creating component is provided that uses minimal average power. For a PIM measurement, two separate signals F1 and F2 are generated to simulate signals, such as from two different types of cell phone operating bands being transmitted in the same area or two different transmit frequencies within one cell phone operating band. PIMs are measured to assure interference is not created on one of the cell phone bands. Minimal power is used by connecting pulse width modulators (PWM) to provide DC power to the high power amplifiers (HPA) creating the signals F1 and F2. By controlling the duty cycle of the PWM to limit ON time of the HPAs to approximately 10%, significant average power savings occur. Size is also reduced with reduced power consumption because heat sinks and other cooling components are not required.

A data receiver, which could be an optical transceiver, a modem, a router hub, is capable of detecting the transmission rate of incoming data. The data is converted to electrical waves appropriate for passive or active bandpass filtering. The frequencies at which the waves are filtered are determined from a plurality of known possible transmission rates and are chosen as having the most detectable difference in the power spectra. By implementing a filter at the corresponding frequency(ies), data having that (those) frequency(ies) will be transmitted. A signal detector then can receive a signal transmitted through the filter and determine the corresponding data rate. It is further contemplated that the multiple frequencies can be filtered by using stages of filters and signal detectors for different frequencies or by filters and detectors capable of multiple frequency operation.

This invention describes a method by which Broadband Spectrum Analysis can be performed in the Rh and Microwave frequency range with significantly higher speed, accuracy, and flexibility than existing RF and Microwave Spectrum Analyzers. This is done by eliminating the need for the filtering of the incoming signal, a process called preselection that needs to track in frequency with the scanning local oscillator in the instrument. By eliminating this requirement, this invention makes possible the identification and analysis of very broadband signals in a single sweep using an Adaptive Sweep Methodology and a Simultaneous Sweep capability that the present invention makes possible.

A method for vector characterization of a frequency translation device (“FTD”) includes coupling a first signal from a first signal source through a reference directional coupler and through a test directional coupler of an electronic test set to a first port of the FTD. A second signal from the reference directional coupler is coupled to a first receiver of a vector network analyzer (“VNA”). A third signal is coupled from the test directional coupler to a second receiver of the VNA; and a vector parameter of the first port of the FTD is measured with the VNA.

A measuring device (e.g., a vectorial network analyzer) by means of at least two ports can be connected to a device under test and has associated excitation / receiving units (ERUs), each thereof having one port. At least one ERU has a signal generator, which can apply an excitation signal onto a device under test. Each ERU possesses two receiving apparatuses (each with a mixer in connection with an oscillator signal) to receive the excitation signal, the reflected signal from the associated port or the signal transmitted to the associated port and converts said signal into an intermediate signal. Each ERU exhibits its own oscillator separate from the signal generator, and generates the oscillator signal for the mixer of the receiving apparatus of the ERU, whereby the frequency and / or phase of the oscillator signals, can be adjusted independently of the frequency and / or phase of oscillator signals of the oscillators of other ERUs.

A spectrum analyzer is provided that includes components to achieve from below 9 kHz to above 20 GHz operation range while remaining hand-held. Components of the spectrum analyzer include an integrated precision stand-alone step attenuator that does not rely on printed circuit board (PCB) mounted circuit elements within the signal path. Further, a PIN diplexing switch separates signals into different base-band and highband paths. The baseband path includes a pre-amplifier for low frequency signals, while the higher frequency bands may not necessarily include a pre-amplifier. The baseband path further provides improved broadband termination of its 1st mixer IF port by incorporating a new quadrature-coupled directional (QCD) filter that includes a ring resonator. An inexpensive air dielectric multi-cavity baseband filter is also used to suppress 2nd mixer IF images. The highband path incorporates multi-throw MMIC PIN diode switches to selectively filter different bands of input signals. At least three total 1st mixers are used to increase operation bandwidth. A phase locked loop providing a 1st LO to the 1st mixers is created that uses a divide-by-two frequency divider in cascade with a sampler-type frequency downconverter. The output of the 1st LO is frequency doubled and filtered to increase the frequency range of the highband signal path.

A preselector is omitted in a spectrum analyzer, for example, which is used to prevent an image signal from being inputted. In addition, an image signal of a signal which is located outside a range of set-up measured frequencies is suppressed as much as possible. For a range of set-up measured frequencies F1˜F2, and for each of a plurality of intermediate frequencies Fi, the frequency of the sweep signal is swept over a range F1+Fi˜F2+Fi to determine first measured data, and is also swept over a range F1−Fi˜F2−Fi to determine second measured data. The first and the second measured data are compared against each other for each measured frequency point, and if they are equal, the data value obtained or a data value having a minimum value unless they are not of an equal value is delivered to obtain measured data in which image data based on image signals has been suppressed.

A frequency detection mechanism for a clock generation unit on an integrated circuit includes a clock generation unit and a detection unit. The clock generation unit may generate an output clock signal at a predetermined frequency that corresponds to a frequency multiple of a reference clock signal provided as an input to the clock generation unit. The detection unit may determine whether the output clock signal is at the predetermined frequency. As such, the detection unit includes a first counter that may generate a first count value based upon the reference clock signal and a second counter that may generate a second count value based upon the output clock signal. The detection unit also includes comparison logic that may perform a plurality of multiplication operations on the first and second count values and generate a final result that indicates whether the output clock signal is at the predetermined frequency.

A method and device for measuring active power of AC with respect to a fundamental frequency or harmonic frequencies using a DPLL include generating via the DPLL a pair of substantially mutually orthogonal sinusoid signals in response to an input voltage data signal, mixing a first sinusoid signal of the pair with a current data signal of the alternating current via a first low-pass filter, mixing the first sinusoid signal of the pair with a voltage signal of the alternating current via a second low-pass filter, and computing an active power of the alternating current based on a further mixing of an output from the first low-pass filter and an output from the second low-pass filter.

In accordance with an embodiment, an apparatus for analyzing signals comprises a spectrum analyzer and a frequency extension module. The spectrum analyzer includes an IF switch which switches between an internal IF signal and an external IF signal, and a LO coupler which is configured to output a portion of one or more LO signals. The frequency extension module is configured to receive the one or more LO signals from the spectrum analyzer and send an IF signal to the spectrum analyzer. A diplexer band switch is used to direct the low band signals to the spectrum analyzer and to direct the high band signals to the frequency extension module where they are downconverted to the external IF which is output to the IF switch.

A frequency detection mechanism for a clock generation unit on an integrated circuit includes a clock generation unit and a detection unit. The clock generation unit may generate an output clock signal at a predetermined frequency that corresponds to a frequency multiple of a reference clock signal provided as an input to the clock generation unit. The detection unit may determine whether the output clock signal is at the predetermined frequency. As such, the detection unit includes a first counter that may generate a first count value based upon the reference clock signal and a second counter that may generate a second count value based upon the output clock signal. The detection unit also includes comparison logic that may perform a plurality of multiplication operations on the first and second count values and generate a final result that indicates whether the output clock signal is at the predetermined frequency.

The invention relates to a photoelectric frequency response tester and a test method thereof. The photoelectric frequency response tester is composed of a frequency shift heterodyne module, a microwave clamp module, a radio frequency module and a control and data processing module. The frequency shift heterodyne module is composed of a directly modulated laser to be tested, a tunable laser, an optical switch, an electro-optic modulator to be tested, an optical frequency shift unit, an optical local oscillation unit, a reference source and a photoelectric detector to be tested. The microwave clamp module provides a microwave switch and different radio frequency port use scenes. The radio frequency module is composed of a main microwave source and an amplitude phase receiving unit. The optical switch and the microwave switch are controlled, the frequency relation of the sinusoidal microwave signals outputted by the main microwave source and the reference source is set, and the required spectrum sideband is analyzed through cooperation of the amplitude phase receiving unit so that the frequency response characteristic parameters of the directly modulated laser to be tested, the electro-optic modulator to be tested and the photoelectric detector to be tested can be acquired, additional calibration test of the conventional method can be eliminated, the test cost of the photoelectronic device can be reduced, and the test accuracy and the flexibility and the reliability of the device can be enhanced.

The invention relates to an apparatus and a method for estimating a fading frequency of incoming received waves in a receiving station of a radio communication system or radio transmission system. An object of the invention is to estimate a fading frequency efficiently and accurately without substantially complexing the configuration of the system. To this end, the invention provides an apparatus for estimating a fading frequency from a pilot signal in a reception signal, which includes a calculation unit for calculating a magnitude of a complex product of two symbols that are received at different instants, and an estimation unit for estimating a fading frequency according to the calculated magnitude of the complex product.

The invention discloses a method and a device for measuring pulse frequency. The method comprises: firstly an RC delay unit stores phase difference information, and charging or discharging operation is carried out by use of a measured signal level in case of change of the measured signal level, wherein, a capacitive voltage reflects the phase difference between a measured signal and a measuring clock; a rising edge phase difference detection unit converts the capacitive voltage on the RC delay unit into digital quantity in the case of rising edge of the measured signal; a falling edge phase difference detection unit converts the capacitive voltage on the RC delay unit into digital quantity in the case of falling edge of the measured signal; a data caching unit caches the converted data; a timing sequence control unit controls the timing sequence of the measurement process; and an embedded single-chip microprocessor carries out compensation on the measured signal by means of the measured phase difference information so as to finally achieve the purpose of measuring the pulse frequency. By adopting the technical scheme, the measurement indeterminacy and errors can be effectively lowered, and the frequency measurement accuracy can be improved; and the real-time property is good, the cost is lower, and the implementation is easy.