The de-Qing loss and phase imbalance caused by the inherent capacitance of a switched resistance, such as a MOSFET with a resistor, can be reduced by using a shunting switch across the resistor that is in series with the resistor's switch. The shunting switch shorts across the resistor when the resistor's switch is open and in reference mode, thereby significantly reducing the resistance in series with the inherent capacitance of the open resistor's switch.

The de-Qing loss and phase imbalance caused by the inherent capacitance of a switched resistance, such as a MOSFET with a resistor, can be reduced by using a shunting switch across the resistor that is in series with the resistor's switch. The shunting switch shorts across the resistor when the resistor's switch is open and in reference mode, thereby significantly reducing the resistance in series with the inherent capacitance of the open resistor's switch.

An LC filter includes an input terminal, an output terminal, a multilayer body, plate electrodes, connection electrodes connecting the plate electrodes, capacitor electrodes, and a inductor vias. Each of the capacitor electrodes opposes the plate electrode. One end of an inductor via is connected with the input terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode. An inductor via is connected between the plate electrode and a capacitor electrode. An inductor via is connected between the plate electrode and a capacitor electrode. One end of an inductor via is connected with the output terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode.

An LC filter includes an input terminal, an output terminal, a multilayer body, plate electrodes, connection electrodes connecting the plate electrodes, capacitor electrodes, and a inductor vias. Each of the capacitor electrodes opposes the plate electrode. One end of an inductor via is connected with the input terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode. An inductor via is connected between the plate electrode and a capacitor electrode. An inductor via is connected between the plate electrode and a capacitor electrode. One end of an inductor via is connected with the output terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode.

Various methods and devices that involve tuning filters are disclosed. A disclosed method for tuning a filter comprises trimming a center frequency of the filter. The method also comprises trimming an input signal magnitude of the filter. The method also comprises measuring a performance metric of the filter after trimming the center frequency of the filter and the input signal magnitude of the filter. The method also comprises repeating the trimming steps and the measuring step until the filter is tuned for a first physical test condition. A disclosed device that includes a filter also includes first and second trimming circuits that trim the center frequency and input signal magnitude of the filter. A disclosed system includes a motor to transfer a transmitting device from a first physical test condition to a second physical test condition relative to a proximity coupling device with a filter.

Various methods and devices that involve tuning filters are disclosed. A disclosed method for tuning a filter comprises trimming a center frequency of the filter. The method also comprises trimming an input signal magnitude of the filter. The method also comprises measuring a performance metric of the filter after trimming the center frequency of the filter and the input signal magnitude of the filter. The method also comprises repeating the trimming steps and the measuring step until the filter is tuned for a first physical test condition. A disclosed device that includes a filter also includes first and second trimming circuits that trim the center frequency and input signal magnitude of the filter. A disclosed system includes a motor to transfer a transmitting device from a first physical test condition to a second physical test condition relative to a proximity coupling device with a filter.

A coupled resonator filter including a first parallel resonator including a first capacitance connected in parallel with a first inductance. The filter includes a second parallel resonator including a second capacitance connected in parallel with a second inductance and a third parallel resonator including a third capacitance connected in parallel with a third inductance. Magnetic coupling between the first inductance and the second inductance, between the second inductance and the third inductance, and between the first inductance the third inductance occurs in accordance with first, second and third coupling factors, respectively. A frequency response of the coupled resonator filter includes a notch when values of the first coupling factor, the second coupling factor and the third coupling factor satisfy predetermined conditions.

A biasing circuit includes a signal input terminal, a signal output terminal, a first inductor, and a second inductor. The first inductor is with one end connected to a node between the signal input terminal and the signal output terminal. The second inductor is with one end connected to an other end of the first inductor. The first inductor includes a core that is formed by a bulk of ferrite. The second inductor includes a core that is formed by a bulk of high permeability material.

A biasing circuit includes a signal input terminal, a signal output terminal, a first inductor, and a second inductor. The first inductor is with one end connected to a node between the signal input terminal and the signal output terminal. The second inductor is with one end connected to an other end of the first inductor. The first inductor includes a core that is formed by a bulk of ferrite. The second inductor includes a core that is formed by a bulk of high permeability material.

In a resonant device, a first via electrode and a second via electrode connect a first plane electrode and a third plane electrode. A third via electrode and a fourth via electrode connect the first plane electrode and a second plane electrode. When the first plane electrode is seen in plan view in a normal direction of the first plane electrode, a first imaginary line connecting the first via electrode and the second via electrode intersects with a second imaginary line connecting the third via electrode and the fourth via electrode.