Abstract: An antenna apparatus for harvesting ambient radio frequency, RF, energy, comprises one or more RF antenna components arranged to receive RF energy. The antenna components comprise a plurality of frequency filtering components, each filtering a respective frequency band of the received RF energy. A rectifying circuit is arranged to convert a variable electrical signal received at an input from an associated antenna, into a direct current electrical signal for supplying to an electrical energy storage unit. A power management module has an input arranged to receive the direct current and control supply of the direct current to the electrical energy storage unit. The rectifying circuit comprises a plurality of transmission lines, and the input of the rectifying circuit and the input of the power management module are connected via the transmission lines. The power management module is arranged at least partially within a boundary defined by the transmission lines.

Abstract: An inductive power transfer system comprises a transmitter circuit comprising a transmitter coil and a receiver circuit comprising a receiver coil spaced from the transmitter coil. The transmitter circuit is in the form of a Class E amplifier with a first inductor and a transistor in series between the terminals of a power supply. A first transmitter capacitance is in parallel with the transistor between the first inductor and a power supply terminal, a primary tank circuit in parallel with the first transmitter capacitance, the primary tank circuit comprising the transmitter coil and a second transmitter capacitance arranged in parallel with the transmitter coil, and a third transmitter capacitance in series with the first inductor between the first transmitter capacitance and the primary tank circuit. The second transmitter capacitance is selected such that a resonant frequency of the primary tank circuit is not equal to the first frequency.

Abstract: An antenna apparatus for harvesting ambient radio frequency, RF, energy, comprises one or more RF antenna components arranged to receive RF energy. The antenna components comprise a plurality of frequency filtering components, each filtering a respective frequency band of the received RF energy. A rectifying circuit is arranged to convert a variable electrical signal received at an input from an associated antenna, into a direct current electrical signal for supplying to an electrical energy storage unit. A power management module has an input arranged to receive the direct current and control supply of the direct current to the electrical energy storage unit. The rectifying circuit comprises a plurality of transmission lines, and the input of the rectifying circuit and the input of the power management module are connected via the transmission lines. The power management module is arranged at least partially within a boundary defined by the transmission lines.

Abstract: Disclosed herein is an antenna apparatus for use in harvesting ambient radio frequency, RF, energy. The apparatus comprises one or more RF antenna components arranged to receive RF energy for producing electricity. The one or more RF antenna components comprise a plurality of frequency filtering components, each frequency filtering component being arranged to filter a respective frequency band of the received RF energy. Also disclosed herein is an apparatus comprising a rectifying circuit arranged to convert a variable electrical signal received at an input from an associated antenna into a direct current electrical signal for supplying to an electrical energy storage unit, the antenna for use in harvesting ambient radio frequency, RF, energy. The apparatus also comprises a power management module having an input arranged to receive the direct current and control supply of the direct current to the electrical energy storage unit.

Abstract: Disclosed herein is an antenna apparatus for use in harvesting ambient radio frequency, RF, energy. The apparatus comprises one or more RF antenna components arranged to receive RF energy for producing electricity. The one or more RF antenna components comprise a plurality of frequency filtering components, each frequency filtering component being arranged to filter a respective frequency band of the received RF energy. Also disclosed herein is an apparatus comprising a rectifying circuit arranged to convert a variable electrical signal received at an input from an associated antenna into a direct current electrical signal for supplying to an electrical energy storage unit, the antenna for use in harvesting ambient radio frequency, RF, energy. The apparatus also comprises a power management module having an input arranged to receive the direct current and control supply of the direct current to the electrical energy storage unit.

Abstract: An inductive power transfer system comprises a transmitter coil TX and a receiver coil RX spaced from the transmitter coil. A transmitter circuit comprises the transmitter coil and is in the form of a Class E amplifier with a first inductor Uchoke and a transistor in series between the terminals of a power supply, a first transmitter capacitor Cpar in parallel with the transistor between the first inductor and a power supply terminal, a primary tank circuit in parallel with the first transmitter capacitor, the primary tank circuit comprising the transmitter coil and a second transmitter capacitor Cres arranged in parallel with the transmitter coil, and a third transmitter capacitor Cser in series with the first inductor between the first transmitter capacitor and the primary tank circuit.