A Phase shift oscillator produces a sine wave. A simple phase shift oscillator circuit contains a RC oscillator which provides less than or equal to 60-degree phase shift.

This paper proposes a new wideband phase shifter, aligning phase slope between the reference line and main line to reduce the slope deviation using 3 types of LC resonance circuits (series, parallel ...

It is shown how switchable one-port circuits having two impedance states may be transformed so as to exhibit reflection coefficients which have a prescribed phase angle difference and equal magnitude ...

When you talk about phase shift in a circuit, you really mean how much the current leads or lags the voltage at a given frequency.