Loss: the phase shifter attenuates while phase shifting
NF: NF = loss
Reciprocity: reciprocal
Analog versus digitaledit
Analog phase shifters provide a continuously variable phase shift or time delay.[7]
Digital phase shifters provide a discrete set of phase shifts or time delays. Discretization leads to quantization errors. Digital phase shifters require parallel bus control.
Differential, single-ended or waveguide:
Differentialtransmission line: A differential transmission line is a balanced two-conductor transmission line in which the phase difference between currents is 180 degrees. The differential mode is less susceptible to common mode noise and cross talk.
Single-ended transmission line: A single-ended transmission line is a two-conductor transmission line in which one conductor is referenced to a common ground, the second conductor. The single-ended mode is more susceptible to common-mode noise and cross talk.