Measurement of inductance values though the use of a charge transfer based measurement system wherein during a first phase, a target inductor is connected to an energy source to allow current through an inductor to increase and in a second phase the inductor is disconnected from the energy source, to allow the current to decrease, and to facilitate transfer of charge to a capacitor. The phases may be repeated, and a count is kept of the number of repetitions.

An inductor that adjust characteristics of a transmit filter circuit is disposed so that the inductor and at least one of common paths, a matching circuit, a receive filter circuit, and receive paths connected to an output terminal of the transmit filter circuit define a propagation path due to magnetic-field coupling and/or electric-field coupling. This configuration does not require the addition of a circuit device to define the propagation path. It is thus possible to improve attenuation characteristics for an RF signal outside the frequency band of a transmitting signal and to improve isolation characteristics between a transmit filter circuit and a receive filter circuit without increasing the size of a radio-frequency module.

An inductor that adjust characteristics of a transmit filter circuit is disposed so that the inductor and at least one of common paths, a matching circuit, a receive filter circuit, and receive paths connected to an output terminal of the transmit filter circuit define a propagation path due to magnetic-field coupling and/or electric-field coupling. This configuration does not require the addition of a circuit device to define the propagation path. It is thus possible to improve attenuation characteristics for an RF signal outside the frequency band of a transmitting signal and to improve isolation characteristics between a transmit filter circuit and a receive filter circuit without increasing the size of a radio-frequency module.

A communications system may include radio frequency (RF) circuitry, an antenna assembly, and an RF cable coupling the RF circuitry and the antenna assembly. The antenna assembly may include an antenna and RF impedance selection circuitry coupled thereto. The RF circuitry may be configured to communicate RF signals with the antenna via the RF cable, and communicate RF impedance selection signals to the RF impedance selection circuitry via the RF cable and using an alternating pulse width modulation scheme.

A system/method describing a physically compact broadband radio frequency (RF) splitter/combiner is disclosed. The system and method provide an alternative to traditional broadband Wilkinson-style RF power splitter/combiners while reducing the overall size of the power divider/combiner to a significantly smaller form factor. The system and method utilize a serpentine impedance network (SIN) that incorporates a mirrored series of positive serpentine node (PSN) traces and negative serpentine node (NSN) traces. The PSN and NSN are coupled together within each isolated and mirrored SIN section with paired coupling traces (PCTs) located between the PSN and NSN traces that serve as both power transformers for the system and as an aid to impedance matching between the RF input port (RIP) and RF output ports (ROPs). The system is electrically symmetric and provides for power splitting and/or combining functionality between the RIP and ROPs.

A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a sensing domain area to change. A portion of the target always lies within at least one of the sensing domain areas of the plane.

There is disclosed a balun for dividing an input electrical signal to produce first and second output electrical signals which are substantially out of phase, the balun including: an input port for receiving the input electrical signal; an input line for coupling the input electrical signal to a slotline; and an output line for coupling the first and second output electrical signals to, respectively a first output port and a second output port, the output line having a junction with the slotline; wherein the slotline couples the input electrical signal to the junction, and the junction acts as a divider to produce the first and second electrical signals; in which at least one of the input line, slotline and output line has a width and a length wherein the width varies over the length.

A communications system may include radio frequency (RF) circuitry, an antenna assembly, and an RF cable coupling the RF circuitry and the antenna assembly. The antenna assembly may include an antenna and RF impedance selection circuitry coupled thereto. The RF circuitry may be configured to communicate RF signals with the antenna via the RF cable, and communicate RF impedance selection signals to the RF impedance selection circuitry via the RF cable and using an alternating pulse width modulation scheme.