Patent ID: 8902113

Claim:
A tunable radiating duplexer comprising: a substrate having a first surface and a second surface opposing the first surface; a first antenna formed on the substrate, the first antenna comprising a first transmission line formed on the first surface of the substrate and a first grounded element formed on the second surface of the substrate substantially opposing the first transmission line, the first grounded element being connected to a first ground, the first transmission line comprising a first end and a second end opposing the first end, the second end being connected to a first short, a first circuit terminal being connected between the first end and the second end, and the first transmission line having a length between 1/50 and 1/12 of a free space wavelength corresponding to a first communications operating frequency; a first variable capacitor attached to the second surface of the substrate, the first variable capacitor comprising first and second terminals, the first terminal being connected through the substrate to the first end of the first transmission line, and the second terminal being connected to the first grounded element; a second antenna formed on the first surface of the substrate, the second antenna comprising a second transmission line formed on the first surface of the substrate and a second grounded element formed on the second surface of the substrate substantially opposing the second transmission line, the second grounded element being connected to a second ground, the second transmission line comprising a first end and a second end opposing the first end, the second end being connected to a second short, a second circuit terminal being connected between the first end and the second end, and the second transmission line having a length between 1/50 and 1/12 of a free space wavelength corresponding to a second communications operating frequency that is different than the first communications operating frequency; and a second variable capacitor attached to the second surface of the substrate, the second variable capacitor comprising first and second terminals, the first terminal being connected through the substrate to the first end of the second transmission line, and the second terminal being connected to the second grounded element.