Abstract: A basic electrical switch for switching alternating (frequency) electrical signals between four symmetrical switching terminals generates, in response to command signals, any of a plurality of switch patterns which provide simultaneous transmission paths between terminals of different pairs and isolation between terminals of different pairs. The switch consists of four hybrid couplers and four reflection-type phase shifters, which are arranged so that the input signal to a coupler is divided equally into two parts, each of which undergoes proper phase shifts by the command signals to emerge from the desired output terminal, either in phase for transmission or out of phase for isolation of the signal. Within each switching state, the signal can also be controlled in biphase by the command signals. The terminals are matched to the characteristic impedance of the switch under any switching state and so, a plurality of such basic electrical switches can be connected at their terminals to provide an "M .times.