System and method for impedance matching an antenna to sub-bands in a communication band

A wireless communications device with a bandwidth segment antenna matching system, the device comprising:

• a transceiver having a wireless communications port to communicate information in a first communication band;
• an antenna having an interface port with a frequency-dependent impedance;
• and
• a sub-band matching circuit including an input port connected to the transceiver wireless communications port and an output port connected to the antenna interface port, the sub-band matching circuit including:
• a first tuning circuit selectively tunable to a first bandwidth segment within the first communication band and selectively tunable to a second bandwidth segment within the first communication band, the first tuning circuit comprising a first tunable ferroelectric (FE) capacitor having a first variable dielectric constant responsive to a first control voltage;
• and,
• a second tuning circuit selectively tunable to a third bandwidth segment within the first communication band when the first tuning circuit is tuned to the first bandwidth segment and selectively tunable to a fourth segment within the first communication band when the first tuning circuit is tuned to the second bandwidth segment, the second tuning circuit comprising a second tunable FE capacitor having a second variable dielectric constant responsive to a second control voltage;
• wherein the first tuning circuit and the second tuning circuit supply a first conjugate impedance for receiving a first set of frequencies in the first and third bandwidth segments and supply a second conjugate impedance for receiving a second set of frequencies in the second and fourth bandwidth segments.

A method for sub-band impedance matching an antenna, the method comprising:

• tuning a first tuning circuit to a first sub-band within a first communication band when receiving communications in the first communication band, comprising the step of:
• applying a first control voltage using a first voltage source to a first tunable ferroelectric (FE) capacitor having a first variable dielectric constant;
• tuning the first tuning circuit to a second sub-band within a second communication band when receiving communications in the second communication band, comprising the step of:
• applying a second control voltage using the first voltage source to the first tunable FE capacitor;
• simultaneously tuning a second tuning circuit to a third sub-band within the first communication band when receiving communications in the first communication band, comprising the step of:
• applying a third control voltage using a second voltage source to a second tunable ferroelectric (FE) capacitor having a second variable dielectric constant;
• simultaneously tuning the second tuning circuit to a fourth sub-band within the second communication band when receiving communications in the second communication band, comprising the step of:
• applying a fourth control voltage using the second voltage source to the second tunable FE capacitor;
• wherein the first tuning circuit and the second tuning circuit supply a first conjugate impedance for receiving the first communication band on the antenna and supply a second conjugate impedance for receiving the second communication band on the antenna.