A digital power amplifier comprising at least two individually activatable amplifiers connected to an output network comprising a first hybrid coupler. An output of a first amplifier is connected to a first input of the first hybrid coupler and an output of a second amplifier is connected to a second input of the first hybrid coupler such that activating an amplifier of the at least two amplifiers causes the amplifier to load modulate another activated amplifier of at least two amplifiers.

To provide an optical 90-degree hybrid formed of a silicon waveguide capable of suppressing an optical loss and a phase error, and facilitating electronic packaging and optical packaging. In the optical 90-degree hybrid circuit including two optical branching units facing each other and two optical coupling units facing away from each other, four arm waveguides are arranged including bent waveguides each of which guides an output light of the optical branching unit to the optical coupling unit, and is formed in a curved shape.

A branchline coupler structure having a pair of main transmission lines disposed on different horizontal levels of a support structure and a pair of shunt transmission lines, vertically disposed and laterally spaced, and disposed in the support structure. A first one of the pair of shunt transmission lines is coupled between: one region of a first one of the pair of main transmission lines and a first end of a second one of the pair of main transmission line. A second one of the pair of shunt transmission lines is coupled between a second region of the first one of the pair of main transmission lines, laterally spaced from the first region, and a second end of the second one of the main transmission lines.

A balanced power amplifier includes a first power amplifier configured to apply a first gain having a first predetermined magnitude and a first programmable phase adjustable phase to generate a first amplified signal, the first programmable phase being adjustable to either a first phase or to a second phase that is 180° phase shifted relative to the first phase; a second power amplifier configured to apply a second gain having a second predetermined magnitude and a second programmable phase to generate a second amplified signal, the second programmable phase being adjustable to either the first phase or to the second phase; and a 90° hybrid coupler configured to receive the first amplified signal and the second amplified signal and generate and output a first output signal or a second output signal based on a combination of the first amplified signal and the second amplified signal.

Embodiments of a method and an apparatus for a quadrature hybrid are disclosed. In an embodiment, a quadrature hybrid includes a first port, a second port, a third port, a fourth port, first, second, and third inductors, first, second, third, and fourth capacitors, and a first variable capacitor tuning network connected between the first port and the fourth port, and a second variable capacitor tuning network connected between the second port and the third port.

A splitter simultaneously inputs two signals having different frequencies within a transmission band to a transmission terminal. A transmission filter system and a reception filter system that are connected to an antenna terminal share a first hybrid coupler. Two transmission filters and a second hybrid coupler are located between the first hybrid coupler and the transmission terminal. A reception filter is located between the first hybrid coupler and the reception terminal.

A circuitry for feeding an antenna structure includes an input for LHCP signals, an input for RHCP signals as well as four antenna outputs. In addition, the circuitry includes first, second and third quadrature hybrids as well as at least two delay lines. The first quadrature hybrid is coupled, on the input side, to the first and second inputs and is coupled, on the output side, to the second and third quadrature hybrids. The second quadrature hybrid is coupled, on the output side, to two of the four antenna outputs, the third quadrature hybrid being coupled, on the output side, to two further ones of the four antenna outputs. The at least two delay lines are arranged at two of the four antenna outputs.

A hybrid coupler operating in a power divider mode includes two inputs, two outputs, a capacitive module coupled between the inputs and the outputs or on each input and each output. The capacitive module has an adjustable capacitive value making it possible to adjust the central frequency. A calibration method includes: delivering a first reference signal having a first reference frequency on the first input of the hybrid coupler, measuring the peak value of a first signal delivered to the first output of the coupler and measuring the peak value of a second signal delivered to the second output of the coupler. The two peak values are compared and an adjustment of the capacitive value of the capacitive module is made until an equality of the peak values is obtained to within a tolerance.

A branchline coupler structure having a pair of main transmission lines disposed on different horizontal levels of a support structure and a pair of shunt transmission lines, vertically disposed and laterally spaced, and disposed in the support structure. A first one of the pair of shunt transmission lines is coupled between: one region of a first one of the pair of main transmission lines and a first end of a second one of the pair of main transmission line. A second one of the pair of shunt transmission lines is coupled between a second region of the first one of the pair of main transmission lines, laterally spaced from the first region, and a second end of the second one of the main transmission lines.

A radio-frequency switching apparatus that can be used to turn a signal path on or off or to attenuate a radio-frequency signal. The switching apparatus comprises at least one radio-frequency input, at least one radio-frequency output, at least one transmission line providing a signal path between the at least one radio-frequency input and the at least one radio-frequency output, and at least one transition metal oxide portion. The radio-frequency switching apparatus also comprises direct current blocking means electrically coupled between the at least one transition metal portion and the at least one radio-frequency input. The radio-frequency switching apparatus also comprises biasing means for providing a bias across the at least one transition metal oxide portion such that power transferred between the radio-frequency input and the radio-frequency output is controlled by controlling the bias level across the at least one transition metal oxide portion.