Antenna with frequency-selective elements

An antenna system comprising:

• a substrate;
• and
• an antenna on the substrate, the antenna comprising a plurality of leg elements, wherein the plurality of leg elements comprises a conductive ink and forms a continuous path;
• wherein:
• at least one of the plurality of leg elements is individually selectable or de-selectable to change a resonant frequency of the antenna, and leg elements that are selected create an antenna path length corresponding to the resonant frequency;
• a first leg element in the plurality of leg elements has a first resonant frequency threshold that is dependent on a received frequency;
• the first leg element is passively de-selected from the antenna path length by being inactive when the received frequency is above the first frequency threshold;
• a second leg element in the plurality of leg elements has a second resonant frequency threshold that is dependent on the received frequency, the second resonant frequency threshold being higher than the first resonant frequency threshold;
• the second leg element is passively selected by resonating when the received frequency is below the second resonant frequency threshold;
• the first resonant frequency threshold is based on a first electrical impedance of the first leg element;
• the second resonant frequency threshold is based on a second electrical impedance of the second leg element, the second electrical impedance being different from the first electrical impedance due to a difference in a material property;
• and
• the material property is selected from the group consisting of:
• a permeability, a permittivity, and a conductivity.

An energy harvesting system comprising:

• A) an antenna system comprising:
• a substrate;
• and
• an antenna on the substrate, the antenna comprising a plurality of leg elements, wherein the plurality of leg elements comprises a carbon-based conductive ink and forms a continuous path;
• wherein each of the plurality of leg elements is individually selectable or de-selectable to change a resonant frequency of the antenna, and leg elements that are selected create an antenna path length corresponding to the resonant frequency;
• and
• B) an electronic circuit having connections to each of the plurality of leg elements;
• wherein the electronic circuit is configured to actively de-select a first leg element in the plurality of leg elements by short-circuiting the first leg element to a second leg element in the plurality of leg elements.

An antenna system comprising:

• a substrate;
• and
• an antenna on the substrate, the antenna comprising a plurality of leg elements, the plurality of leg elements comprising a conductive ink and forming a continuous path;
• wherein:
• a first leg element in the plurality of leg elements has a first resonant frequency threshold that is dependent on a received frequency and a first electrical impedance of the first leg element;
• the first electrical impedance is based on a material property selected from the group consisting of:
• a permeability, a permittivity, and a conductivity;
• and
• the first leg element is individually de-selectable to change a resonant frequency of the antenna by changing an antenna path length, the first leg element being passively de-selected from the antenna path length by being inactive when the received frequency is above the first frequency threshold.