Abstract: An exemplary tunable circuit includes an inductor coupled to a node and a first capacitor coupled to the node. The tunable circuit also includes a variable capacitor coupled to the node, such that a total capacitance of the tunable circuit depends on a fixed capacitance of the first capacitor and a variable capacitance of the variable capacitor. In an example, the inductor and the first capacitor are both included in a passive device and the variable capacitor is in a semiconductor device. The variable capacitor allows the total capacitance to be modified for the purpose of, for example, calibrating the capacitance to account for manufacturing variations, and/or adjusting to a frequency range of operation used by wireless devices in a region of the world. The first capacitor may be a higher quality capacitor providing a larger portion of the total capacitance than the variable capacitor.

Abstract: An exemplary tunable circuit includes an inductor coupled to a node and a first capacitor coupled to the node. The tunable circuit also includes a variable capacitor coupled to the node, such that a total capacitance of the tunable circuit depends on a fixed capacitance of the first capacitor and a variable capacitance of the variable capacitor. In an example, the inductor and the first capacitor are both included in a passive device and the variable capacitor is in a semiconductor device. The variable capacitor allows the total capacitance to be modified for the purpose of, for example, calibrating the capacitance to account for manufacturing variations, and/or adjusting to a frequency range of operation used by wireless devices in a region of the world. The first capacitor may be a higher quality capacitor providing a larger portion of the total capacitance than the variable capacitor.

Abstract: An RF antenna switch and a method for operating the antenna switch are disclosed. In an embodiment the antenna switch includes an antenna terminal and a switch including a number of n I/O terminals and n?x transceiver units, wherein each transceiver unit is configured to operate in a frequency band of a respective communication system, and wherein n and x are integers and n, x?1 and n>x. The switch is further adapted to independently connect a plurality of the I/O terminals to the antenna terminal to provide a respective signal paths from the antenna terminal to the I/O terminals, wherein a first filter is connected between a first I/O terminal and a common input node of a first transceiver unit, the first filter being adapted to filter out an unwanted harmonic mode produced by a transmitter of the first transceiver unit.

Abstract: An RF antenna switch and a method for operating the antenna switch are disclosed. In an embodiment the antenna switch includes an antenna terminal and a switch including a number of n I/O terminals and n-x transceiver units, wherein each transceiver unit is configured to operate in a frequency band of a respective communication system, and wherein n and x are integers and n, x?1 and n>x. The switch is further adapted to independently connect a plurality of the I/O terminals to the antenna terminal to provide a respective signal paths from the antenna terminal to the I/O terminals, wherein a first filter is connected between a first I/O terminal and a common input node of a first transceiver unit, the first filter being adapted to filter out an unwanted harmonic mode produced by a transmitter of the first transceiver unit.

Abstract: There is an antenna, three feed ports, two switches, and two impedances. In an embodiment, the first and second feed ports interface respective FM transmitter and FM receiver, and the third feed port interfaces Bluetooth, WLAN and/or GPS radios. The two switches are disposed along the antenna. A first throw of them renders a balanced mode for the antenna seen by the first feed port and a second throw renders an unbalanced mode for the antenna seen by the second feed port. The two impedances are disposed and configured such that the antenna, for signals in a second frequency band at the third feed port and which are impeded by the two impedances, is an unbalanced mode for the first throw of the switches and is an unbalanced mode for the second throw of the switches. Also detailed is a method for making an electronic device having such an antenna.