Patent classifications
H03H7/0161
In-circuit calibration of anti-aliasing filter
A computer-implemented method according to one embodiment includes performing anti-aliasing filtering on each of a plurality of signals, each signal having a frequency that is a different fraction of a frequency of a data read clock. An amplitude of each of the signals is measured after the anti-aliasing filtering. In response to the amplitudes of the signals being within a predefined range, anti-aliasing settings used during the anti-aliasing filtering are stored. In response to the amplitudes of the signals being outside the predefined range, the anti-aliasing settings are changed. A computer program product according to another embodiment includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. The program instructions are executable by a processing circuit to cause the processing circuit to perform the foregoing method.
SWITCH COMPONENT, HIGH-FREQUENCY MODULE, AND COMMUNICATION APPARATUS
A switch component includes a common terminal, at least two selection terminals, a switching circuit that selectively connects the common terminal to each of the at least two selection terminals, and an inductor. One end of the inductor is connected to one of the at least two selection terminals. The switching circuit is integrated with the inductor.
High-frequency filter, front-end circuit, and communication device
A high-frequency filter includes a variable frequency filter, a fixed frequency filter, and switches. The variable frequency filter varies a passband in association with frequencies used in multiple communication band. The fixed frequency filter fixes a passband in association with a frequency used in a specific communication band different from the multiple communication bands. The switches are used to switch connection configuration to the variable frequency filter or the fixed frequency filter.
RECEIVER ARCHITECTURE FOR DIGITAL ISOLATORS EMPLOYING NOTCH FILTERS FOR COMMON MODE TRANSIENT IMMUNITY
A technique for attenuating common mode transient events uses a differential receiver circuit including a band-stop filter having a stopband f.sub.SB around a notch frequency f.sub.n of a received signal. The differential receiver circuit includes a first high-pass filter coupled in series with the band-stop filter. The notch frequency f.sub.n is less than a carrier frequency f.sub.c of a signal received by the differential receiver circuit. The band-stop filter may include a buffer circuit and a notch filter coupled in series with the buffer circuit. The notch filter may have a second stopband around the notch frequency f.sub.n. The differential receiver circuit may have a propagation delay that is independent of a pulse width of common mode transient energy attenuated by the differential receiver circuit.
Alternating anti-parallel diode mixer structure
An apparatus includes a first circuit and a second circuit. The first circuit may have a first diode and a second diode connected as anti-parallel diodes and physically adjacent to each other in a substrate. The second circuit may have a third diode and a fourth diode connected as anti-parallel diodes and physically adjacent to each other in the substrate. The first circuit and the second circuit may be configured to mix two input signals to generate an output signal. A polarity of every other physically neighboring diode may be reversed.
FILTER CIRCUITS HAVING A RESONATOR-BASED FILTER AND A MAGNETICALLY-COUPLED FILTER
Filter circuits having a resonator-based filter and a magnetically-coupled filter are disclosed. A filter circuit is deployed with a resonator-based passband filter connected to a magnetically-coupled filter which mitigates or reduces flyback of the resonator-based filter. The magnetically-coupled filter can be a passband filter with a relatively low insertion loss. The magnetically-coupled filter can be designed to mitigate flyback of the resonator-based filter by attenuating frequency response at selected frequency ranges.
COMPOSITE FILTER APPARATUS, HIGH-FREQUENCY FRONT END CIRCUIT, AND COMMUNICATION APPARATUS
A composite filter apparatus includes a common terminal, a transmission-side terminal, a reception-side terminal, a transmission filter, and a reception filter with a pass band higher than the pass band of the transmission filter. The transmission filter is connected between the common terminal and the transmission-side terminal and the reception filter is connected between the common terminal and the reception-side terminal. An inductor is provided between the common terminal and the reception filter in a path between the common terminal and the reception-side terminal. The resonant frequency of a parallel-arm resonator closest to the common terminal in the reception filter is lower than a high end frequency of the pass band of the transmission filter and is lower than the resonant frequencies of the other parallel-arm resonators in the reception filter.
Variable filter circuit and radio communication device
A variable filter circuit (10) includes a parallel arm (11) connected between a port (P3) and node (A), a series arm (12) including a resonator (Re_s1) connected in series between a port (P1) and node (A), and a series arm (13) including a resonator (Re_s2) connected in series between a port (P2) and node (A). The parallel arm (11) includes a first inductor (Lp1). The series arms (12, 13) include variable capacitors (Cp_s1, Cp_s2) connected in parallel to the resonators (Re_s1, Re_s2).
Adaptive Tuning Networks with Direct Mapped Multiple Channel Filter Tuning
A flexible multi-path RF adaptive tuning network switch architecture that counteracts impedance mismatch conditions arising from various combinations of coupled RF band filters, particularly in a Carrier Aggregation-based (CA) radio system. In one version, a digitally-controlled tunable matching network is coupled to a multi-path RF switch in order to provide adaptive impedance matching for various combinations of RF band filters. Optionally, some or all RF band filters include an associated digitally-controlled filter pre-match network to further improve impedance matching. In a second version, some or all RF band filters coupled to a multi-path RF switch include a digitally-controlled phase matching network to provide necessary per-band impedance matching. Optionally, a digitally-controlled tunable matching network may be included on the common port of the multi-path RF switch to provide additional impedance matching capability. In a third version, CA direct mapped adaptive tuning networks include filter tuning blocks for selected lower frequency bands.
Systems and methods for minimizing insertion loss in a multi-mode communications system
Methods and system for using a multifunctional filter to minimize insertion loss in a multi-mode communications system are described. Specifically described is a multifunctional filter that is configurable to operate in a band-pass mode when a first type of signal is propagated through the multifunctional filter, and to operate in a low-pass mode when a second type of signal is propagated through the multifunctional filter. The multifunctional filter presents a lower insertion loss to the second type of signal when operating in the low-pass mode than in the band-pass mode.