Abstract: An integrated circuit for cancelling a radio frequency transmit leakage signal comprises: a transmitter portion comprising at least one amplifier stage for transmitting a radio frequency signal to an antenna port; and a first coupler arranged to operably couple the transmitter portion, the antenna port and a receiver portion. The receiver portion is arranged to receive a first composite signal that comprises a received radio frequency signal from the antenna port and the transmit leakage signal.

Abstract: An integrated circuit for phase shifting a radio frequency signal, wherein the integrated circuit comprises at least one phase shifter comprising: at least one input for receiving a radio frequency signal, a voltage variable element; and a plurality of active devices operably coupled to the voltage variable element and arranged to receive a variable control voltage. The plurality of active devices comprise at least two active devices coupled in a common base arrangement and arranged to receive the radio frequency signal with the voltage variable element coupling the emitter contacts or source contacts of the at least two active devices, such that a variable control voltage applied to the voltage variable element adjusts a phase of the radio frequency signal.

Abstract: A multichannel receiver system comprises a first plurality of receiver circuits, each having a first input connected to a corresponding one of a second plurality of input lines, each being arranged to provide a corresponding one of a third plurality of received signals; a second input connected to a local oscillator arranged to provide a local oscillator signal; and an output arranged to provide a corresponding one of a fourth plurality of output signals; and an upconversion mixer having a first mixer input for receiving a reference signal; a second mixer input connected to the local oscillator; and a mixer output providing an upconverted reference signal to a fifth plurality of directional couplers, each directional coupler connected to a corresponding one of the second plurality of input lines.

Abstract: A communication unit comprises a controller and a radio frequency signal path having a plurality of delay elements operably coupled to a series of respective amplifier stages, wherein the controller is arranged to individually enable the respective amplifier stages. In response thereto a number of the plurality of delay elements are selectively inserted into or by-passed from the radio frequency signal path thereby adjusting a phase shift applied to signals provided through the radio frequency signal path.

Abstract: An integrated circuit comprises a receiver and an oscillator circuit. The receiver has a first input port for receiving a first oscillatory input signal, a second input port for receiving a second oscillatory input signal, and an output port for delivering an oscillatory output signal which is a function of both the first input signal and the second input signal. The oscillator circuit has a first output port for delivering a first oscillatory signal, and a second output port for delivering a second oscillatory signal. The first output port of the oscillator circuit is coupled to the HF port, and the second output port of the oscillator circuit is coupled to the LO port. The integrated circuit may be designed such that the HF port may be disconnected from the first output port of the oscillator circuit without affecting the operability of the receiver. An apparatus for testing the proper functioning of an integrated circuit as described above and a method of producing a receiver are also disclosed.

Abstract: A down-conversion module for a heterodyne receiver comprises a first mixer circuit, a second mixer circuit and an interconnection. The first mixer circuit includes first and second differential control terminals and is arranged to produce a first down-converted differential voltage signal at a first down-converted frequency as a function of a first RF differential input signal applied to the first differential control terminals and of a first RF differential reference frequency signal applied to the second differential control terminals.

Abstract: A temperature compensation circuit, comprises a temperature sensor circuit. The circuit comprises two or more temperature sensitive devices. In use, the devices are operated at different current densities and sense virtually the same ambient temperature. The devices provide temperature dependent signals having linear components with slopes of identical signs. The circuit further comprises one of more differential signal providing device for generating a difference of the signals generated by the temperature sensitive devices. A method for generating a voltage reference with a well-defined temperature behaviour, comprises applying different current densities to two or more temperature sensitive devices of a temperature sensor circuit; sensing virtually the same ambient temperature with the two or more temperature sensitive devices.