Abstract: The length of a transmission line delay circuit is halved by inserting a directional coupler in the signal path ahead of the transmission line and either open circuiting or short circuiting the other end of the transmission line. The signal traveling through the directional coupler and through the transmission line is reflected back at the end of the transmission line, and the reflected signal is carried to the coupled output of the directional coupler. Since the signal travels through the transmission line twice, the delay time is doubled. Therefore, for a given delay requirement, the length of transmission line required is only half of the length required for prior art transmission delay lines.

Abstract: The invention discloses an antenna system, which includes an array structure provided with a plurality of radiator elements being adapted to transmit and receive radiated electromagnetic waves. Each of the radiator elements are provided with at least two transverse interconnecting slots forming an aperture. An array feed network is operatively associated with each radiator element and is adapted to transmit a signal to and receive a signal from each radiator element and is further adapted to provide at least one common feed point for the array structure. A phase shifting unit operatively joins each radiator element to its associated feed point, the phase shifting unit being adapted to selectively adjust a phase of the electromagnetic waves associated with each radiator element. Operation of each phase shifting unit is regulated by control means for controlling the generation of a radiation pattern.