Abstract: A heterodyne radio receiver, having a broadband IF, in which the outputs from the second down-conversion mixer of the receiver are high pass filtered to select unwanted signals and low pass filtered to select wanted signals, the unwanted signals being up-converted to IF in an up-conversion mixer, phase shifted and added in anti-phase to an input or inputs of the second down-conversion mixer.

Abstract: A folding mobile phone with incorporated antenna is disclosed. A folding mobile phone comprises a first and second housings connected by a hinge mechanism each other. A first conductive film is incorporated with the first housing, and a second conductive film is incorporated with the second housing. When the mobile phone is in an open position a monopole antenna is constituted by the first and second conductive films, when the mobile phone is in a closed position the second conductive film acts as a ground plane.

Abstract: An antenna for a folding mobile phone comprises two main sections connected by a hinge mechanism. When the mobile phone is in the open position (the normal operating position), the antenna comprises a planar conducting sheet combined with a slotted plate and acts as a monopole. When the mobile phone is in the closed position (the standby position), the antenna comprises the slotted plate acting as a slot antenna with the planar conducting sheet forming a reflector.

Abstract: The antenna comprises a single rectangular sheet of copper which has been bent firstly to produce a first patch antenna section 1 and secondly to produce a second patch antenna section 3, sections 1 and 3 being joined by and contiguous with section 2. Section 2 is an integral part of the copper sheet and maintains the two sections 1 and 3 in substantially parallel spaced relationship with each other. An air gap 4 exists between sections 1 and 3. Other low absorption insulators may be used in place of air gap 4 and may be selected from a range of such insulators well known in the art. The antenna is backed by a ground plane 6 and is fed by means of a coaxial connector 5 to the distal edge of the larger patch at 7 where excitation of the antenna is effected.