Methods and apparatus for a signal isolator having reduced parasitics. An example embodiment, a signal isolator and include a first metal region electrically connected to a first die portion, a second die portion isolated from the first die portion, and a second metal region electrically connected to the second die portion. A third metal region can be electrically isolated from the first and second metal regions and a third die portion can be electrically isolated from the first, second and third metal regions. In embodiments, the first metal region, the second metal region, and the third metal region provide a first isolated signal path from the first die portion to the second die portion.

Disclosed is a microwave cavity resonator used as a phase change (phase modulation) to intensity change (intensity or amplitude modulation) converter. Certain aspects and embodiments include resonant circuits, such as a resistor, inductor and capacitor (RLC) circuit. Certain aspects and embodiments convert changes in phase to changes in output voltage to perform analog demodulation of a phase modulated microwave carrier. Certain aspects and embodiments use resonance when the reactive components of the circuit (capacitive and inductive components) are equal in magnitude and 180 degrees out of phase with one another, thereby cancelling out the reactance component of the circuit's impedance.

Disclosed is a microwave cavity resonator used as a phase change (phase modulation) to intensity change (intensity or amplitude modulation) converter. Certain aspects and embodiments include resonant circuits, such as a resistor, inductor and capacitor (RLC) circuit. Certain aspects and embodiments convert changes in phase to changes in output voltage to perform analog demodulation of a phase modulated microwave carrier. Certain aspects and embodiments use resonance when the reactive components of the circuit (capacitive and inductive components) are equal in magnitude and 180 degrees out of phase with one another, thereby cancelling out the reactance component of the circuit's impedance.

A radio frequency circuit includes a first acoustic wave filter that is connected to a common terminal and includes a first acoustic wave resonator, a first LC filter that is connected to the common terminal via the first acoustic wave filter and includes at least one of an inductor or a capacitor, a second acoustic wave filter that is connected to the common terminal and includes a second acoustic wave resonator, and a second LC filter that is connected to the common terminal via the second acoustic wave filter and includes at least one of an inductor or a capacitor.

A capacitive-coupled level shifter includes a capacitive divider circuit having a first capacitive divider branch configured to couple a first input terminal to a first comparator terminal and a second capacitive divider branch configured to couple a second input terminal to a second comparator terminal. The first capacitive divider branch and the second capacitive divider branch are symmetric so as to cancel out a common mode voltage of a modulated signal input to the capacitive divider circuit. A level shifter system which includes the capacitive-coupled level shifter is also described.

According to one embodiment, there is provided a magnetic coupling device including a first coil, a second coil, a third coil, a fourth coil, a first constant-potential node and a second constant-potential node. The second coil is electrically connected with one end of the first coil and wound in a direction opposite to a direction in which the first coil is wound. The third coil faces the first coil. The fourth coil faces the second coil. The first constant-potential node is electrically connected with one end of the third coil. The second constant-potential node is electrically connected with one end of the fourth coil.

According to one embodiment, there is provided a magnetic coupling device including a first coil, a second coil, a third coil, a fourth coil, a first constant-potential node and a second constant-potential node. The second coil is electrically connected with one end of the first coil and wound in a direction opposite to a direction in which the first coil is wound. The third coil faces the first coil. The fourth coil faces the second coil. The first constant-potential node is electrically connected with one end of the third coil. The second constant-potential node is electrically connected with one end of the fourth coil.

A multilayer coil component includes a multilayer body that is formed by laminating a plurality of insulation layers and that includes a coil inside thereof and outer electrodes provided on an outer surface of the multilayer body and electrically connected to the coil. The coil is formed by connecting a plurality of coil conductors, laminated together with insulation layers, via a connection conductor. At a connection portion at which the first coil conductor and the second coil conductor, being coil conductors adjacent to each other, are connected via the connection conductor, a conductor width of the connection conductor is smaller than a conductor width of the first coil conductor and a conductor width of the second coil conductor is smaller than the conductor width of the first coil conductor.

Methods and apparatus for a signal isolator having reduced parasitics. An example embodiment, a signal isolator and include a first metal region electrically connected to a first die portion, a second die portion isolated from the first die portion, and a second metal region electrically connected to the second die portion. A third metal region can be electrically isolated from the first and second metal regions and a third die portion can be electrically isolated from the first, second and third metal regions. In embodiments, the first metal region, the second metal region, and the third metal region provide a first isolated signal path from the first die portion to the second die portion.

An LC resonator includes an external connection terminal, an inductor, a capacitor, and a via conductor pattern. The inductor winds around an axis orthogonal to a laminated direction. The capacitor is connected to the inductor. The via conductor pattern extends from the inductor in the laminated direction, and the inductor is connected to the external connection terminal with the via conductor pattern. The inductor includes a columnar conductor pattern extending in the X-axis direction. The area of the columnar conductor pattern in a plan view from the X-axis direction is greater than or equal to the area of the via conductor pattern in a plan view from the Z-axis direction.