Abstract: A slot antenna is described. The slot antenna includes a waveguide having a first side, a second side, a third side, and a fourth side, a closed end and an open end. The second side extends substantially perpendicularly from a first end of the first side. The third side extends substantially perpendicularly from a second end of the first side. The fourth side extends between the second side and the third side with the fourth side substantially parallel to the first side. The sides and the closed end form a cavity. A feeding point is located substantially midway between the first end of the first side and the second end of the first side. A T-Bar is located inside the cavity, the T-bar having a center member extending from the feeding point into the cavity and a cross member having a length extending across the cavity between the second side and the third side.

Abstract: An antenna driving circuit for connecting an antenna to two transmitters is disclosed. The antenna driving circuit includes a hybrid combiner that has two isolated inputs. The hybrid is configured so that when a first signal is input to the first input, substantially one half of the energy of the first signal is output at the first output and the first signal is phase shifted by about −90 degrees at the first output. Substantially one half of the energy of the first signal is output at the second output and the first signal is phase shifted by about 0 degrees at the second output. When a second signal is input to the second input, substantially one half of the energy of the second signal is output at the second output and the second signal is phase shifted by about −90 degrees at the second output. Substantially one half of the energy of the second signal is output at the first output and the second signal is phase shifted by about 0 degrees at the first output.

Abstract: An antenna driving circuit for connecting an antenna to two transmitters is disclosed. The antenna driving circuit includes a hybrid combiner that has two isolated inputs. The hybrid is configured so that when a first signal is input to the first input, substantially one half of the energy of the first signal is output at the first output and the first signal is phase shifted by about -90 degrees at the first output. Substantially one half of the energy of the first signal is output at the second output and the first signal is phase shifted by about 0 degrees at the second output. When a second signal is input to the second input, substantially one half of the energy of the second signal is output at the second output and the second signal is phase shifted by about -90 degrees at the second output. Substantially one half of the energy of the second signal is output at the first output and the second signal is phase shifted by about 0 degrees at the first output.