Abstract: In some embodiments, a power amplification system can comprise a current source, an input switch configured to alternatively feed current from the current source to a high-power circuit path and a low-power circuit path, and a band switch including a switch arm for switching between a plurality of bands. Each of the high-power circuit path and the low-power circuit path can be connected to the switch arm.

Abstract: A second member is joined in surface contact with a first surface of a first member including a semiconductor region made from an elemental semiconductor. The second member includes a radio-frequency amplifier circuit made from a compound semiconductor. A conductive protrusion projects from the second member toward a side opposite to the first member. The first member includes a temperature measurement element that detects a temperature.

Abstract: Disclosed is a terminated spread-spectrum waveguide-to-coaxial converter, which relates to the technical field of waveguide converters. The converter includes an upper cavity, a lower cavity, a cover plate and a connector, where a waveguide cavity is formed between the upper cavity and the lower cavity, openings are formed on a left side and a right side of the waveguide cavity, the cover plate is fixed to an outer side of a left end opening of the waveguide cavity, the connector is fixed to an outer side of the cover plate, and a coaxial inner conductor on the connector passes through a through hole formed on the cover plate to enter the waveguide cavity.

Abstract: Disclosed is an amplifier having a high slew rate without increasing power consumption. The amplifier includes an input unit, a conversion unit, an amplification unit, a frequency compensation circuit, and a slew rate improvement circuit. Alternatively, the amplifier includes an input unit, a conversion unit, an amplification unit, a frequency compensation circuit, a first slew rate improvement circuit, and a second slew rate improvement circuit.

Abstract: A driving circuit of a loudspeaker includes a periodic signal generation circuit, a signal processing circuit, a class-D amplifier circuit, a current sensing circuit, and a sample and hold circuit. The periodic signal generation circuit is arranged to generate a periodic signal and a control signal. The signal processing circuit is coupled to the periodic signal generation circuit, and is arranged to generate a pre-driving signal. The class-D amplifier circuit is coupled to the signal processing circuit, and is arranged to drive the loudspeaker according to the pre-driving signal. The current sensing circuit is coupled to the class-D amplifier circuit, and is arranged to generate a current sensing signal. The sample and hold circuit is coupled to the periodic signal generation circuit and the current sensing circuit, and is arranged to sample and hold the current sensing signal according to the control signal, to generate a current sampling signal.

Abstract: A differential feedback circuit with an active noise cancelation technique using a dual input differential pair. In the differential feedback circuit, a feedback voltage and a reference voltage connect to a primary input pair. Sensed noise at the inputs is put to a secondary input pair of the differential amplifier, which is inverted with respect to the primary input pair. In other words, the reference voltage, which may be subject to noise, connects directly to one terminal of the secondary input pair and through a low-pass filter to another terminal of the secondary input pair so that the noise, which may be coupled to the differential feedback circuit, cancels at the output of the differential feedback circuit.

Abstract: A phase shifter for altering the phase of a radio frequency signal is disclosed herein. A Lange coupler is used having reflective ports that are coupled to artificial transmission lines. The artificial transmission lines provide a reflection transmission path, the length of which can be determined by digital control lines. Transistors placed along the length of the central trace provide independent paths to ground that serve to shorten the electrical length of the ATL. Accordingly, by selectively turning the transistors on/off, the electrical length of the ATL can be selected and thus the amount of phase delay introduced by the phase shifter.

Abstract: Circuits and methods for achieving good amplifier AM-AM and AM-PM metrics while achieving good power, PAE, linearity, and EVM performance. Embodiments compensate for a non-linear distortion profile (e.g., an AM-PM and/or AM-AM profile) in an amplifier by pre-processing an input signal, such as a radio-frequency signal, to alter the non-linear distortion profile of the input signal so as to compensate for the non-linear distortion profile imposed by a coupled device, such as an amplifier.

Abstract: A current sensor architecture is implemented using a trans-resistance amplifier circuit having a low pass filter characteristic. The current sensing resistor and the input resistors for the amplifier circuit are matched thermally so that they have substantially identical temperature coefficients. The feedback resistors, which are coupled in parallel with corresponding capacitors, are implemented using switched capacitor circuits that emulate resistors. With this configuration, the current sensor is temperature insensitive.

Abstract: Aspects of this disclosure relate to multiplexers with acoustic wave resonators. The multiplexer includes a first filter and a second filter. The first filter includes a plurality of bulk acoustic wave resonators and a shunt surface acoustic wave resonator. The shunt acoustic wave resonator can have a resonant frequency in a passband of the second filter. The passband of the second filter is below a passband of the first filter. In certain applications, the first filter is a receive filter and the second filter is a transmit filter.

Abstract: A LNA (low-noise amplifier) includes a matching network configured to provide a three-way coupling between an input node, a matched node, and a source node; a gate capacitor configured to provide AC (alternate current) coupling between the matched node and a gate node; a cascode amplifier configured to receive a gate voltage at the gate node and output an output voltage at an output node in accordance with a source degeneration at the source node; and a load network connected to the output node, wherein the matching network having a shunt inductor and a series inductor that are overlapped in layout to have a strong mutual coupling and a source degenerating inductor that is laid out in a close proximity to the shunt inductor to have a strong mutual coupling.

Abstract: An acoustic wave device includes a first substrate, an acoustic wave element provided on a first surface of the piezoelectric layer, a second substrate, a first metal layer provided on the first surface and conductively connected to the acoustic wave element, a second metal layer provided on a second surface of the second substrate, a third metal layer that connects the first metal layer to the second metal layer, is thicker than the first metal layer and the second metal layer, and contains copper or silver, and a first conductive layer that covers a side surface of the third metal layer, and a third surface of the first metal layer in a region surrounding another region where the third metal layer is bonded to the first metal layer, is thinner than the third metal layer, and contains a component other than copper, silver, and tin as a main component.

Abstract: Aspects of this disclosure relate to acoustic wave filter. The acoustic wave filter can include different types of acoustic wave resonators. The acoustic wave filter can include shunt acoustic wave resonator that has lower second harmonic distortion than other acoustic wave resonators of the acoustic wave filter. In certain embodiments, the shunt acoustic wave resonator can be a surface acoustic wave resonator. Related multiplexers, radio frequency modules, wireless communication devices, and methods are also disclosed.

Abstract: An electrical component, such as an RF device or thermal bridge, for use with a printed circuit board. The component has a first dielectric layer having a top and a bottom, a first conductive trace positioned on the bottom of the dielectric layer, and a first ground layer positioned on the bottom of the dielectric layer and spaced apart from the first conductive trace. For RF applications, a second conductive trace is positioned on top of first dielectric, a second dielectric is positioned on top of the second conductive trace, and a second ground plane is positioned on top of the second dielectric. A printed circuit board having a third conductive trace may then be coupled to the first conductive trace by a first solder layer.

Abstract: An adaptive continuous-time linear equalizer (CTLE) includes a CTLE cell including input terminals and output terminals, a low-pass filter configured to respectively output low-band differential signals obtained by respectively low-pass filtering differential output signals, and an error amplifier configured to amplify a difference between the low-band differential signals and output the difference as a control voltage. The CTLE cell includes first and second transistors each including an input terminal and an output terminal and an offset compensator configured to adjust a potential difference between a supply voltage source and the output terminal according to the control voltage.

Abstract: Reversed semilattice filters with improved common mode rejection characteristics are disclosed. In one aspect, a filter may include two interior nodes coupled with an impedance that treats unwanted signals as common mode signals and provides rejection for common mode signals while passing differential signals of interest. The impedance is modified to have a resonant circuit that improves signal rejection in the stop band by lowering the effective impedance at those frequencies while leaving the pass band unaffected.

Abstract: A polarizer for a waveguide, comprising a main body for transmitting an electromagnetic wave, a first delay member being provided in the main body. A second delay member arranged downstream of the first delay member in the working direction (A) of the electromagnetic wave is provided in the main body, and the polarization axis (P2) of the second delay member is rotated relative to the polarization axis (P1) of the first delay member by a delay angle (?).

Abstract: Trim layers that are configured to adjust one or more operating parameters for surface acoustic wave (SAW) devices are disclosed. A SAW device may include an interdigital transducer (IDT) and a piezoelectric material that are configured to generate an acoustic wave and a trim layer that has an acoustic velocity and a density that correspond to a velocity of the acoustic wave. In this manner, the trim layer may be configured to adjust an electromechanical coupling of the SAW device without significantly impacting a resonance frequency of the SAW device. The SAW device may also include an additional trim layer that is configured to adjust a coupling percentage and the resonance frequency of the SAW device. A SAW device may include a trim layer that is configured to adjust certain operating parameters by greater amounts than other operating parameters.

Abstract: A device and method for transitioning between a rectangular waveguide (RWG) and a substrate integrated waveguide (SIW) or air-filled SIW (AFSIW) in millimeter wave communication systems. The transition apparatus includes a pair of hollow metallic structures, each featuring a tapered body connecting RWG and SIW (or AFSIW) interfaces. The tapered bodies facilitate a seamless transition with lengths ranging from approximately 1 mm to 15 mm, accommodating SIW and AFSIW substrate heights from about 0.2 mm to 1.0 mm. The apparatus ensures impedance matching within a specified range, maintains a voltage standing wave ratio between 1 and 5, and achieves a total reflection coefficient between ?20 dB and ?10 dB. Additionally, the apparatus exhibits high modal purity, with dominant mode levels between-1 dB and 0.25 dB, and significantly attenuated non-dominant modes. The apparatus supports efficient signal transmission within the frequency range of approximately 50 GHz to 75 GHz.

Abstract: An acoustic wave device includes a support substrate, a piezoelectric body, an acoustic layer laminate, first and second electrodes, and a lead-out electrode. The first electrode is on a first main surface of the piezoelectric body, the second electrode is on a second main surface of the piezoelectric body, the lead-out electrode is on the first main surface or the second main surface of the piezoelectric body, the lead-out electrode is electrically connected to the first electrode or the second electrode, side surface grooves extend from the first main surface side of the piezoelectric body, and the side surface grooves are provided in at least a portion of a remaining portion excluding a portion provided with the lead-out electrode from a region in an outer side portion of at least one of the first electrode and the second electrode.