An interdigitated RF filter. The interdigitated RF filter includes input fingers connected to an input node and output fingers connected to an output node where at least one input finger is connected the output node or at least one output finger is connected to the input node. The described interdigitated RF filter can be implemented in various configurations such as series, shunt, ladder or a combination thereof.

Provided by a bandpass filter circuit and a multiplexer. The bandpass filter circuit includes at least one electromagnetic LC filter circuit and at least one acoustic wave resonance unit. The at least one acoustic wave resonance unit includes an input port, an output port, at least one circuit element and at least three resonators. The at least one electromagnetic LC filter circuit is electrically connected to the at least one acoustic wave resonance unit, and the at least three resonators include at least one first resonator and at least one second resonator. In a case where the at least one first resonator includes one first resonator, the first resonator is connected in series between the input port and the output port.

An RF power detector adapted to detect an RF power of an RF signal, includes, in part, an antenna adapted to receive the RF signal, a narrow-band RF power converter adapted to convert the RF signal to a DC signal, an accelerometer, and a magnetometer. The accelerometer and magnetometer are adapted to determine the orientation and location of the power detector. The power detector optionally includes a gyroscope. The narrow-band RF power converter may be a rectifier tuned to the frequency of the RF signal. The power detector optionally includes an indicator adapted to provide information representative of the amount of the DC power of the DC signal, as well as position and orientation of the power detector. The power detector may be adapted to be inserted into a mobile device so as to provide the information about the amount of DC power, orientation and position to the mobile device.

Systems, devices, and methods for adjusting tuning settings of tunable components, such as tunable capacitors, can be configured for calibrating a tunable component. Specifically, the systems, devices and methods can measure a device response for one or more inputs to a tunable component, store a calibration code in a non-volatile memory that characterizes the device response of the tunable component, and adjust a tuning setting of the tunable component based on the calibration code to achieve a desired response of the tunable component.

A radio frequency (RF) filter having a first passband and including a first circuit connected to a first node and a second node disposed on a path that connects a first terminal and a second terminal, and a second circuit connected to the first node and the second node. The first circuit includes a first filter having a second passband that includes a portion of a frequency range of the first passband and a bandwidth narrower than a bandwidth of the first passband. The second circuit includes a second filter having a third passband that includes a portion of a frequency range of the first passband and has a bandwidth narrower than the bandwidth of the first passband. The RF filter also includes a first phase shifter connected to a first terminal of the second filter; and a second phase shifter connected to a second terminal of the second filter.

In some embodiments, a differential oscillator includes a differential circuit coupled between a first output node and a second output node and a transformer-coupled band-pass filter (BPF). The transformer-coupled BPF is coupled between the first output node and the second output node and includes a coupling device and a transformer. The coupling device is coupled between the first output node and the second output node. The transformer includes a first winding coupled between the first output node and a voltage node and a second winding coupled between the second output node and the voltage node.

A multiplexer includes: a first terminal; a second terminal; a third terminal; a first filter connected between the first and second terminals, including a first capacitor, a first inductor, and one or more first acoustic wave resonators, and having a first passband; a second filter connected between the first and third terminals, including a second capacitor, a second inductor, and one or more second acoustic wave resonators, and having a second passband higher than the first passband; a substrate having a surface on which at least one first acoustic wave resonator of the one or more first acoustic wave resonators and at least one second acoustic wave resonator of the one or more second acoustic wave resonators are located; and a metal structure located on the surface and located between the at least one first acoustic wave resonator and the at least one second acoustic wave resonator.

A coupled resonator filter is disclosed. The coupled resonator filter is provided with high quality factor, and comprises: a first resonance unit, a second resonance unit and a main adjustment unit. In the present invention, the main adjustment unit is electrically connected between the first resonance unit and the second resonance unit, and comprises an adjustable capacitor. By changing a capacitance of the adjustable capacitor, a coupling coefficient between the first resonance unit and the second resonance unit is adjusted. As a result, the coupled resonator filter of the present invention included advantages of high controllability of the frequency bandwidth and high inhibition rate of noise signal.

A coupled resonator filter is disclosed. The coupled resonator filter is provided with high quality factor, and comprises: a first resonance unit, a second resonance unit and a main adjustment unit. In the present invention, the main adjustment unit is electrically connected between the first resonance unit and the second resonance unit, and comprises an adjustable capacitor. By changing a capacitance of the adjustable capacitor, a coupling coefficient between the first resonance unit and the second resonance unit is adjusted. As a result, the coupled resonator filter of the present invention included advantages of high controllability of the frequency bandwidth and high inhibition rate of noise signal.

A filtering circuit includes a filter, a frequency divider, and a control circuit. The filter is configured to generate a first oscillating signal according to a control signal in a first mode, and perform a filtering process according to the control signal in a second mode. A frequency of the first oscillating signal is determined according to the control signal. The frequency divider is coupled to the filter and configured to divide the frequency of the first oscillating signal to generate a frequency-divided signal. The control circuit is coupled to the filter and the frequency divider, and configured to compare a frequency of the frequency-divided signal and a frequency of a second oscillating signal so as to adjust the control signal in the first mode. A center frequency of a passband of the filter in the second mode is determined according to the adjusted control signal.