Abstract: A receiver has a first (12) and a second radio system (14). The first radio system (12) is a zero-power system and the second radio system (14) can either be in an active-state or in an off-state. The first radio system (12) is designed to bring the second radio system (14) from an off-state back into an active state upon receipt of a dedicated radio signal.

Abstract: A transceiver comprises transmitter means and receiver means, mode means coupled to the transmitter means and the receiver means for simultaneously performing a receiving and transmitting of signals, oscillator means coupled to each of the transmitter means and the receiver means respectively, and frequency divider means coupled between the oscillator means on the one hand and the transmitter means, and receiver means respectively on the other hand. Such a transceiver is capable of operating in full duplex mode without the necessity to adding extra oscillator means to achieve such an operational mode, while in addition this saves components, costs, chip area, power dissipation and weight, which is important for in particular mobile communication applications.

Abstract: In a diode mixer circuit MIX, a driving circuit DRIV produces a first, second, third and fourth drive signal DS1, DS2, DS3, DS4. Each drive signal is a combination of a first and a second input signal LO, RF with the following signs: DS1: +LO+RF DS2: +LO−RF DS3: −LO+RF DS4: −LO−RF A first, second, third and fourth diode D1, D2, D3, D4 transfer the first, second, third and fourth drive signal DS1, DS2, DS3, DS4 respectively, to an output O1. The first and fourth diodes D1, D4 have the same polarity relative to the output. The second and third diodes D2, D3 also have the same polarity relative to the output, but opposite to that of the first and fourth diodes D1, D4. A mixer circuit of this type is suitable for a relatively large variety of applications, notably because it may be realized in the form of an integrated circuit.

Abstract: A device for processing electromagnetic waves in the microwave range, with a body provided with a circuit element which is electrically connected to a strip-type transmission line which comprises conductor tracks, said body being mechanically connected to an insulating substrate via contact bodies. The transmission line is formed by conductor tracks which lie on mutually facing surfaces of the body and the insulating substrate, respectively. The transmission line in the device is present between the body and the insulating substrate, the contact bodies providing a separation between the conductor tracks. Thus, it is not necessary then to use a second side of the body remote from the insulating substrate for the manufacture of transmission lines.

Abstract: A differential amplifier comprises differential main current streams, a controlled current source means to feed the main current streams, the controlled current source means having a control input for controlling the main current streams, and a saturation sensing circuit coupled between the main current streams and the control input for generating a control input signal in dependence of saturation sensed in at least one of the main current streams. The differential amplifier has an improved large signal behaviour at low power dissipation and increased efficiency.

Abstract: A radio transmission system is disclosed for operating in a multipath transmission environment having improved reception, and in the case of bi-directional systems, also improved transmission. This is achieved by using at least two reception beams, corresponding to one fixed reception beam and one scanning reception beam, and by continuously evaluating the quality of these beams as to their signal-to-noise-and-interference ratios or bit-error-rates (BERs). The best beam is dynamically chosen to be the fixed beam. Alternatively, the fixed beam is updated with the best beam acquired by the scanning beam as compared to the current fixed beam. In a bi-directional system, the receiving radio apparatus applies the direction of the best reception beam for transmission to the opposite radio apparatus.

Abstract: In a quadrature receiver for phase and/or frequency modulated signals an intermediate phase signal is quantized to produce a quantized phase signal. The receiver includes a demodulator in which pulses are generated from the quantized phase signal and it is determined whether two successive pulses have different polarities, and if so, a reconstructed baseband signal transition is produced at a predetermined reconstruction instant between the two successive pulses. The reconstruction instant is chosen in the middle between two successive pulses for FSK modulation, and it is chosen at different positions between the two pulses for other types of modulation, such as GMSK or multi-level FSK.

Abstract: A radio transmission system comprises a phased-array radio apparatus for optimizing reception in a multipath transmission environment. In the phased-array radio apparatus, phase shifting is performed after down-conversion of received RF signals. Phase control and beam-forming are simple. By applying a zero-IF or low-IF receiver structure, the complete structure can easily be fully integrated.

Abstract: A device compensated for an undesired capacitance includes a first and a second node between which nodes the undesired capacitance is present. A diode driven in breakthrough is coupled between the first and the second node. As a diode driven in breakthrough exhibits the characteristics of a negative capacitance, a compensation of the undesired capacitance is achieved.

Abstract: Analog-to-digital converter operating in parallel having an analog signal input and a number of digital signal outputs, comprising a plurality of comparators having each two inputs and one output, one input being connected to an impedance network for supplying this one input with its own predetermined reference voltage, and the second input being connected to the analog signal input for receiving an analog input signal to be converted, so that each of the comparators processes a predetermined input signal portion. The comparator outputs are coupled to corresponding digital signal outputs, while delay elements are inserted between the comparator outputs and the corresponding digital signal outputs for causing a delay to occur related to the steepness of the slope of the input signal portion of the relevant comparator.