A variable phase-shifter having a variable phase-shifting performance capable of dealing with small phase-shift amounts is thereby obtained.

An optical phase shifter including a constant phase shift element or a variable phase shift element, each introducing a desired and predetermined phase shift into an optical signal passing through the phase shifter.

The voltage control signal (VPHS) may be configured to control the variable phase shift.

The varying phase shift produced by each phase shifter controls the antenna's radiating direction.

A similar transformer (40) can be used to impose a selective variable phase -shift on the RF power from the source.

A variable attenuator and a variable phase shift circuit can be integrated with each amplifier and can be used for beam shaping and electronic beam pointing.

A coefficient controller (58) is operative to set the first and second adaptive coefficients and to separately set the variable phase shift responsively to the output samples.

The varying phase shift is used to indicate fluctuations over time in the local height of the liquid surface in the target area.

Any phase or amplitude changes in the current signal through sensor (2) appear in the signal applied to variable phase shift circuit (5).

The varying phase shift is either used to control an antenna's radiating direction, or is detected by a measuring device to test the material itself.

It has a splitter (44) dividing a radio frequency (RF) carrier signal into two signals between which a phase shifter (46) introduces a variable phase shift.

An oscillator (4) applies a voltage signal to the sensor (2) and the voltage across resistor (3) is applied to a variable phase shift circuit (5), the output of which is applied to a variable gain amplifier (6).

Each phase unit (8) comprises a waveform generator (18) configured to generate an analogue waveform having a frequency corresponding to a time-varying phase shift.

The disclosed invention relates to a device to efficiently realize (that is, with low dissipative loss) a large variable phase shift in a millimeter wavelength electromagnetic wave.

Furthermore, an unknown, variable phase-shift (φSP) in the preprocessed signal (uf) may be determined by varying the ratio between the spurious component and a particle-dependent target component.