An ultra-wide band circulator apparatus, comprising: (a) delay lines comprising a plurality of delay line segments (60, 62, 64, 66, 72, 74); (b) a plurality of switches with each switch (56, 58, 68, 70, 76) coupled to two or more of said plurality of delay line segments (60, 62, 64, 66, 72, 74) to form a sequentially-switched delay line (SSDL); (c) wherein each said switch (56, 58, 68, 70, 76) in said sequentially-switched delay line (SSDL) is configured for being sequentially turned on and off to connect different paths along adjoining delay line segments; (d) a transmitter input and a receiver output; (e) wherein said switches comprise (i) a first pair of switches, the first one of the first pair coupling the transmitter input to a selected first or second of the delay line segments corresponding respectively to a first and second transmission path, the second one of the first pair coupling the receiver output to a selected third or fourth of the delay line segments corresponding respectively to a first and second reception path, (ii) a second pair of switches, the first one of the second pair coupling either the first transmission path or the first reception path to a fifth of the delay line segments, the second one of the second pair coupling either the second transmission path or the second reception path to a sixth of the delay line segments, (iii) wherein said first transmission path and said second reception path are direct paths from the first pair of switches to the second pair of switches, and in said second transmission path and in said first reception path the corresponding delay line segments cross over from said first pair of switches to the second pair of switches, (iv) wherein said first and second pairs of switches allow selectively routing signals to, or from, either of the first pair of switches or the second pair of switches, depending on the direction of signal travel; (f) wherein said second pair of switches is configured for connection to an antenna multiplexor/demultiplexor through either the fifth or sixth delay line segments; and (g) wherein said switches (56, 58, 68, 70, 76) are sequentially switched for synchronicity with a first pulsed transient signal corresponding to a transmission wave and a second pulsed transient signal corresponding to a received wave, for redirecting the first and second pulsed transient signals along the different transmission and reception paths to separate the signals, thus providing seamless transmission of both transmitted waves and received waves without stop or reflections. (a) delay lines comprising a plurality of delay line segments (60, 62, 64, 66, 72, 74); (b) a plurality of switches with each switch (56, 58, 68, 70, 76) coupled to two or more of said plurality of delay line segments (60, 62, 64, 66, 72, 74) to form a sequentially-switched delay line (SSDL); (c) wherein each said switch (56, 58, 68, 70, 76) in said sequentially-switched delay line (SSDL) is configured for being sequentially turned on and off to connect different paths along adjoining delay line segments; (d) a transmitter input and a receiver output; (e) wherein said switches comprise (i) a first pair of switches, the first one of the first pair coupling the transmitter input to a selected first or second of the delay line segments corresponding respectively to a first and second transmission path, the second one of the first pair coupling the receiver output to a selected third or fourth of the delay line segments corresponding respectively to a first and second reception path, (ii) a second pair of switches, the first one of the second pair coupling either the first transmission path or the first reception path to a fifth of the delay line segments, the second one of the second pair coupling either the second transmission path or the second reception path to a sixth of the delay line segments, (iii) wherein said first transmission path and said second reception path are direct paths from the first pair of switches to the second pair of switches, and in said second transmission path and in said first reception path the corresponding delay line segments cross over from said first pair of switches to the second pair of switches, (iv) wherein said first and second pairs of switches allow selectively routing signals to, or from, either of the first pair of switches or the second pair of switches, depending on the direction of signal travel; (f) wherein said second pair of switches is configured for connection to an antenna multiplexor/demultiplexor through either the fifth or sixth delay line segments; and (g) wherein said switches (56, 58, 68, 70, 76) are sequentially switched for synchronicity with a first pulsed transient signal corresponding to a transmission wave and a second pulsed transient signal corresponding to a received wave, for redirecting the first and second pulsed transient signals along the different transmission and reception paths to separate the signals, thus providing seamless transmission of both transmitted waves and received waves without stop or reflections.