An antenna system including: a metal base plate; an antenna element arranged on and extending away from the front side of the base plate; a circuit board including a ground plane, adjacent to, and in thermal contact with the base plate; a plurality of electrical components on the circuit board including a power amplifier and an I/O connector; a metal support plate separated from, parallel to, and facing the base plate, with the circuit board located between the base and support plates; a plurality of thermally conductive standoffs thermally connecting the base plate to the support plate; and a master board including an I/O connector mating with the I/O connector on the circuit board and electrically connecting the circuit board to the master board, the master board located between the circuit board and the support plate and including signal paths for routing signals to the circuit board.

An antenna-matching device includes a first antenna terminal that is connected to a first radiating element, a second antenna terminal that is connected to a second radiating element, power feeding terminals and that are connected to a power-feeding unit C, an antenna coupling circuit (coupling inductance element L) that is connected in series between the antenna terminals, and a matching unit B that is connected between the antenna terminals and the power feeding terminals. The coupling inductance element L and the matching unit are integrally provided in a substrate. The matching circuit B is connected in series with the signal lines and includes a first resonant circuit and a second resonant circuit that have different resonant frequencies from each other and are coupled with each other. The matching unit B is connected to a power-feeding circuit that includes an RF circuit.

An antenna-matching device includes a first antenna terminal that is connected to a first radiating element, a second antenna terminal that is connected to a second radiating element, power feeding terminals and that are connected to a power-feeding unit C, an antenna coupling circuit (coupling inductance element L) that is connected in series between the antenna terminals, and a matching unit B that is connected between the antenna terminals and the power feeding terminals. The coupling inductance element L and the matching unit are integrally provided in a substrate. The matching circuit B is connected in series with the signal lines and includes a first resonant circuit and a second resonant circuit that have different resonant frequencies from each other and are coupled with each other. The matching unit B is connected to a power-feeding circuit that includes an RF circuit.

A wide band antenna comprising a signal generator coupled to a feed region of at least one antenna element comprising upper and lower loops. Upper loop comprising a first conductive loop element defined by an upper conductor and a first conductive blade tapering outwardly forming a flare portion adjacent a distal end of the upper conductor. Lower loop comprising a second loop defined by a base conductor and a second conductive blade tapering outwardly forming a flare portion adjacent a distal end of the base conductor, first and second conductive blades defining, between their facing edges, a notch opening outwardly from feed region. The method comprising matching an antenna element impedance to the transmission line; selecting an antenna element cut-off frequency; selecting an upper conductor length, and subsequently selecting dimensions of the upper loop such that they are substantially equal to a wavelength corresponding to the selected cut-off frequency.

A wide band antenna comprising a signal generator coupled to a feed region of at least one antenna element comprising upper and lower loops. Upper loop comprising a first conductive loop element defined by an upper conductor and a first conductive blade tapering outwardly forming a flare portion adjacent a distal end of the upper conductor. Lower loop comprising a second loop defined by a base conductor and a second conductive blade tapering outwardly forming a flare portion adjacent a distal end of the base conductor, first and second conductive blades defining, between their facing edges, a notch opening outwardly from feed region. The method comprising matching an antenna element impedance to the transmission line; selecting an antenna element cut-off frequency; selecting an upper conductor length, and subsequently selecting dimensions of the upper loop such that they are substantially equal to a wavelength corresponding to the selected cut-off frequency.

A method of manufacturing and an antenna having an upper and lower loop. Upper loop comprising a first conductive loop defined by an upper conductor and a first conductive blade tapering outwardly to form a flare portion adjacent a distal end of the upper conductor. Lower loop comprising a second conductive loop defined by a base conductor and a second conductive blade tapering outwardly forming a flare portion adjacent a distal end of the base conductor. First and second conductive blades defining, between their facing edges, a notch opening outwardly from a feed region. Upper loop further comprising an elongate conductive vane extending at an angle from a first location on the upper conductor to a second location on the first conductive blade defining a pair of loops within the upper loop.

A method of manufacturing and an antenna having an upper and lower loop. Upper loop comprising a first conductive loop defined by an upper conductor and a first conductive blade tapering outwardly to form a flare portion adjacent a distal end of the upper conductor. Lower loop comprising a second conductive loop defined by a base conductor and a second conductive blade tapering outwardly forming a flare portion adjacent a distal end of the base conductor. First and second conductive blades defining, between their facing edges, a notch opening outwardly from a feed region. Upper loop further comprising an elongate conductive vane extending at an angle from a first location on the upper conductor to a second location on the first conductive blade defining a pair of loops within the upper loop.

An antenna and a mobile terminal with the antenna including a first radiator and a first capacitor structure. A first end of the first radiator is electrically connected to a signal feed end of a printed circuit board by means of the first capacitor structure, and a second end of the first radiator is electrically connected to a ground end of the printed circuit board. The first radiator, the first capacitor structure, the signal feed end, and the ground end form a first antenna, configured to generate a first resonance frequency. An electrical length of the first radiator is less than or equal to one eighth of a wavelength corresponding to the first resonance frequency.

A wireless sensor includes a substrate, an antenna, a sensing element, a transmission line, and a sensing integrated circuit (IC). The sensing element is positioned on one end of the substrate and the antenna is positioned on an opposite end of the substrate. The sensing IC is coupled to the sensing element and to the antenna via the transmission line. The sensing IC is operable to receive a sensed condition of the item from the sensing element. The sensing IC is further operable to determine an input impedance of the wireless sensor based on the sensed condition and convert it into a digital value that is representative of the condition of the item. The sensing IC is further operable to output, via the antenna, the digital value or a representation of the condition of the item.

A non-contact communication apparatus 100 includes an antenna resonant unit 110 and an antenna drive unit 130. In the antenna drive unit 130, for example, a measurement unit consisting of an differential amplifier A3 measures an output current from an oscillation unit 131. A control unit 140 detects a minimum value or maximum value of the output current. The resonant frequency is controlled by the use of an optimal control value corresponding to the minimum value or maximum value. Therefore, even if the resonant frequency fluctuates due to variations in antenna characteristics in manufacture or a usage environment or aging, satisfactory communication characteristics at a set resonant frequency can be obtained.