Abstract: A quadrature switching mixer is provided for mixing a received RF signal and a local oscillator signal, while rejecting an image signal associated with the RF signal. Input signal components in quadrature, that is, I and Q input components derived from the received RF signal, are respectively coupled through first and second input paths to corresponding commuting switches in a configuration of switches. Each of the switches operates to multiply respective quadrature components of RF and local oscillator signals to provide quadrature output signal components. A unidirectional device, such as a buffer amplifier included in a signal splitter, is placed in each input path to prevent any portion of an output signal component from leaking backward through one of the input paths to the other input path, and thus to the other output signal component.

Abstract: An electronic communications device having a proximity sensor comprising: communication means (7) and a proximity sensor adapted to provide a control signal (Y2; Y3; Y4) indicative of whether an object (8) is in proximity of the device. The device is characterized by having a proximity sensor coil (L1; L2; L3; L5; L6; LP; LL) with an impedance, and oscillation means (C1, C2, 302; 601; 804) coupled to the proximity sensor coil (L1; L2; L3; L5; L6; LP; LL) to provide the control signal (Y2; Y3; Y4) in response to the impedance. In a preferred embodiment the proximity sensor coil is a loudspeaker coil. The invention also relates to a method of detecting proximity of an object relative to a loudspeaker (11; 703; 803) with a loudspeaker coil (L5; L6) which has an impedance.

Abstract: An electronic device (1), e.g. a mobile telephone having a front cover (6) and a capacitive proximity sensor, comprising: a first electrode (9; 27) and a second electrode (8; 21, 20), said first electrode having a large face (11, 12, 13; 29); and detector means connected to the first electrode (9, 27) and the second electrode (8, 21, 20) for detecting the capacitance of the first electrode relatively to the second electrode and for providing a control signal (Vprox) responsive to the capacitance. The large face (11, 12, 13; 29) of the first electrode is inclined relative to the front cover (6).