Patent classifications
H03H11/12
Optical receiver
A receiver has a differential transimpedance amplifier (4) with two inputs and two outputs. The differential transimpedance amplifier (4) provides a differential output and this is peak-detected (15, 16) to provide amplitude reference signals. The differential transimpedance amplifier output and the amplitude reference signals are fed to a differential summing amplifier (10), which provides a fully differential signal to a comparator, or to an automatic gain control circuit (5) to regulate the differential transimpedance amplifier gain. The differential summing amplifier (10) output is a fully differential signal, thereby having lower distortion for DC and burst mode receiver applications.
Active Antenna for Wireless Local Area Network Devices
Various embodiments are described herein that improve the signal reception and transmission capabilities of an access point by coupling an active antenna assembly to the access point. An active antenna assembly includes an antenna and at least one active component, such as a low-noise amplifier or a power amplifier. The active component can be connected to an antenna circuit board rather than the main circuit board of the access point, which is typically retained within an access point housing. By positioning the active component near the antenna, the active antenna assembly prevents degradation of signals received by the antenna. One or more coaxial cables can be used to connect the active component of the active antenna assembly to the main circuit board of the access point.
SYSTEM AND METHOD FOR A RADIO FREQUENCY FILTER
In accordance with an embodiment, a method of operating an RF system includes filtering a first wideband RF signal using a wideband filter bank. Filtering the first RF signal includes separating the first wideband RF signal into frequency cluster signals, where each frequency cluster signal of the frequency cluster signals includes different frequency ranges, the first wideband RF signal includes multiple RF bands, and each of the different frequency ranges comprises a plurality of RF bands of the multiple RF bands. The method further includes band stop filtering at least one of the frequency cluster signals to produce a band stopped frequency cluster signal.
Band pass filter and sensor device including the same
A sensor device includes: first sensors; second sensors which form capacitances with the first sensors; a sensor transmitter connected to the first sensors, where the sensor transmitter supplies driving signals to the first sensors; and a sensor receiver connected to the second sensors, where the sensor receiver receives sensing signals from the second sensors, and the sensor receiver includes a band pass filter which filters the sensing signals. The band pass filter includes: a first integrator including a first amplifier; a first high pass filter converter connected to a first input terminal, a second input terminal and a first output terminal of the first amplifier, where the first high pass filter converter time-divisionally provides N high pass filter conversion paths; and a first gain auxiliary component connected to the first input terminal and the first output terminal of the first amplifier while the first integrator performs an integral function.
FILTER CIRCUIT
A filter circuit for use with a system configured to be coupled with an electrical load, the filter circuit comprising a first filter, wherein the first filter is configured to receive a first voltage and provide an output voltage, the output voltage being the first voltage after filtering by the first filter, and the filter circuit is configured to adjust the bandwidth of the first filter in response to a load transient.
Logarithmic demodulator for laser Wavelength-Modulaton Spectroscopy
Systems, devices, and methods including a first band-pass filter configured to receive and filter a detector signal, where the first band-pass filter has a central frequency of 2f; a second band-pass filter configured to receive and filter the detector signal where the second band-pass filter has a central frequency of 1f; a first logarithmic amplifier (Log Amp) configured to apply the filtered detector signal from the first band-pass filter; a second Log Amp configured to apply the filtered detector signal from the second band-pass filter; a differential amplifier configured to subtract the applied signal from the first Log Amp from the applied signal from the second Log Amp; and an Anti-Log Amplifier configured to determine an inverse logarithm of the subtracted signal from the differential amplifier.
BASELINE RESTORER CIRCUIT
A baseline restorer circuit including a controller; a sample control circuit arranged to receive an input voltage signal that is output from a circuit stage comprising an amplifier, and configured to capture a sample of the input voltage signal at a sampling time in response to receiving a control signal from the controller; an analogue processing stage to receive the sample and a constant baseline reference voltage and selectively process the sample to provide an output voltage; a transconductance stage to convert the output voltage to a compensation current and supply the compensation current to an input of the circuit stage; and a change detector to monitor if the input voltage signal changes during a time interval around the sampling time, and if no change is detected in the input voltage signal during the time interval, the controller is configured to control the analogue processing stage to process the sample.
Accurate calibration of analog integrated-circuits continuous-time complex filters
A first and second input tone are applied to a continuous-time complex filter within an integrated circuit. The magnitude of the output of the filter at the frequency of each of the first and second input tones are measured and compared to determine the value of a filter tuning control signal. A tuning control signal is applied to the filter with the determined value to tune the filter.
Method and apparatus for nonlinear signal processing
The present disclosure relates to a concept of nonlinear signal processing which may be used for predistortion for RF power amplifiers. The concept includes generating time variant filter coefficients for a linear filter circuit based on a nonlinear mapping of an input signal, and filtering the input signal with the linear filter circuit using the time variant filter coefficients in order to generate a filtered output signal. Thus, it is proposed to implement a non-linear filter by a time-varying linear filter where the time-varying coefficients are derived from the input signal.
Filter Circuit with Programmable Gain and Frequency Response
A filter circuit includes a filter and a current mode programmable gain amplifier, where the filter circuit is configured to filter an input signal to obtain an output signal. The filter is supplied with the input signal. The filter comprises at least one current extraction element configured to extract a first output current signal. The current mode programmable gain amplifier is configured to receive and amplify the first output current signal to obtain an amplified current signal. The output signal is derived from the amplified current signal.