Abstract: A Sigma-Delta modulator(10) comprises a signal put(34) coupled to a forward filter comprising a series connection of a plurality of N summing stages(28, 30, 32), where N is an integer of at least 2, alternating with a corresponding plurality of integrating stages(40, 42, 44) and an analogue to digital converter(ADC)(18) having an input coupled to an output of the Nth integrating stage(44) and an output. A feedback filter comprises a feedback coupling from the output of the ADC(18) to a digital to analogue converter(DAC)(26) which is coupled to an input of each of the summing stages by way of respective weights(46, 48, 50). Control means(66) including switching means (58, 64) are provided for changing the order of the modulator. To reduce the order and increase the bandwidth, the control means by-passes the first(40) of the integrating stages and uses the second(42) of the integrating stages as a first of the integrating stages and vice versa to increase the order and decrease the bandwidth.

Abstract: RF amplifiers used in communications systems exhibit backward intermodulation caused by non-linear amplification. Backward intermodulation of the transmit signal and an external signal, which reaches the output of the amplifier through the antenna, results in an unwanted third-order intermodulation product that potentially interferes with the proper reception of the receive signal. The receive sensitivity of the communications system is adversely affected by this unwanted third-order intermodulation product. By mixing a second-order intermodulation component, caused by the same backward intermodulation, with the transmit signal, a compensation signal is created allowing the cancellation of the unwanted third-order intermodulation component.

Abstract: The chips for chip cards are customarily provided on a film strip which consists of a synthetic foil and a conductor track pattern and are connected to the conductor track pattern by way of bonding wires. Automatic mounting is made possible by the use of a film strip with periodically arranged conductor track patterns. For chips which can be driven via contacts as well as in a contactless manner, using a coil, conductor tracks are effectively provided on both sides of the synthetic foil forming the film strip. However, the film strip then becomes very inflexible so that it cannot be suitably handled by conventional automatic apparatus. The invention proposes to provide the metal foils wherefrom the conductor tracks are cut out with additional interruptions which reduce the cross-section of the metal foils at short intervals in the direction perpendicular to the longitudinal direction of the film. The film strip thus becomes more flexible so that it can be handled by conventional automatic apparatus.

Abstract: An apparatus and method for reducing the non-uniformity of a positron emission tomography (“PET”) image is described. The event detector system comprises a detector having a plurality of zones, each zone comprising a plurality of detector devices. The event detector system also comprises a threshold circuit coupled to a detector device of the detector. Additionally, the event detector system comprises a summation circuit coupled to the threshold circuit.

Abstract: A data carrier (1) which can be operated in a contact-bound mode and in a contactless mode and a circuit (1A) for such a data carrier (1) has supply voltage generating means (35), for deriving a supply voltage (VDD) for various circuit sections of the data carrier (1) and of the circuit (1A) from a received useful HF signal (HF), and additional switching means (91) by means of which the application of a potential (VDD), which appears as a result of the supply voltage generated by the supply voltage generating means (35), to at least one contact terminal (17A) can be inhibited.

Abstract: A CMOS Class F amplifier uses a differential input to eliminate even-order harmonics, thereby avoiding the need for circuits that are tuned to the second harmonic. This also minimizes the sensitivity of the design to changes in the second harmonic frequency and/or the particular component values selected for the tuned circuit. Third-order harmonics are reduced by controlling the phase relationship between the differential inputs. Additional efficiency is achieved by dynamically controlling the impedance of the amplifier as a function of output power level.

Abstract: A data carrier has a carrier body with a recess, an insulating layer with an outer surface exposed to an environment of the data carrier and with an inner surface, a chip module that is mounted in the recess, and a transmission coil with coil contacts. The chip module has a chip with chip contacts, a cover of electrically insulating material, and a metal lead frame. The transmission coil is mounted in a zone outside the chip module. The metal lead frame has a first part, a second part and a third part. The first, second a third parts are substantially coplanarly arranged with respect to each other. The first part carries the chip at a side remote from the environment, and the second and third parts form lead frame contacts that are electrically coupled to the coil contacts and the chip contacts. The insulating layer and a cover part inside the data carrier form the cover.