Patent ID: 8130054

Claim:
Radio frequency (RF) isolator circuitry comprising: control circuitry adapted to select one of a first operating mode and a second operating mode; and a variable isolation circuit comprising: an electro-magnetic gyrator adapted to: substantially process a first RF signal in a forward direction by applying about zero phase-shift to the first RF signal; and substantially process a second RF signal in a reverse direction by applying a first phase-shift to the second RF signal; and a variable impedance circuit coupled to the electro-magnetic gyrator and adapted to present a first impedance to the electro-magnetic gyrator during the first operating mode and present a second impedance to the electro-magnetic gyrator during the second operating mode, the variable isolation circuit adapted to operate as a bandpass filter when processing the first RF signal, and operate as a notch filter when processing the second RF signal, such that the notch filter has a first notch frequency during the first operating mode and a second notch frequency during the second operating mode.