Abstract: A transmitting and receiving arrangement for operation in any selected one of plural frequency ranges includes at least one transmitting power amplifier and at least one low noise input amplifier allocated respectively to each frequency range. The arrangement includes plural chips, that each include at least one input amplifier and at least one transmitting amplifier incorporated therein, e.g. in an integrated circuit. The input amplifier and the transmitting amplifier allocated to a particular frequency range are located on different chips. The input amplifier and the transmitting amplifier incorporated in one chip are allocated to different frequency ranges. In a communication in a given frequency range, the transmission amplification is handled through one chip and the input amplification is handled through a different chip. The dissipated heat from the transmitting amplifier does not directly heat and deteriorate the performance of the input amplifier allocated to the active frequency.

Abstract: One or more transponders are selected by a base station out of a plurality of transponders. For this purpose an identification bit sequence (IB) that is or includes a random number bit sequence (ZB) is made available in the respective transponder and the base station transmits in a bit-by-bit fashion a selection bit sequence (AB) to the transponders. These sequences (IB or ZB) and (AB) are compared bit-by-bit in the respective transponder. The comparing is performed by way of a predeterminable comparing criterion to provide a comparing result in the form of a selection bit to which a bit value is assigned. The selection is then made depending on the bit value of the selection bit of the respective transponder.

Abstract: Data encoded in packets modulated onto a carrier wave is transmitted between a base station and a transponder. Each packet includes a header section containing at least a reference symbol, and a further section such as a data section. In the transponder, the time duration of the reference symbol is determined, and a parameter is adjusted dependent on the determined duration. The parameter determines at least a property, such as the time resolution, of the encoding and/or decoding operation, and may be the clock frequency of a counter circuit or the charging current of an RC-circuit used to determine the duration of the symbols. The parameter may initially be set to a minimum default value, which is increased if the determined duration is less than or equal to a specified threshold. Thereby, power consumption is minimized while ensuring reliable encoding and decoding over a large range of transmission distances.

Abstract: In a bi-directional contactless data transmission, a procedure aims to prevent the communication distance from being extended by unauthorized persons using radio repeaters. The procedure involves establishing a fixed relationship of a selected physical parameter of an electromagnetic signal. For example, the frequency of the signal received by a transponder is multiplied with a number to provide a different frequency, and a response signal having this different frequency is transmitted back to a base unit. In the base unit, the received frequency of this response signal is divided by the same number and the result is compared to the frequency of the originally emitted signal. If the resulting difference is below a preset threshold, then there is a fixed frequency relationship between the two signals, the process concludes that there has been no unauthorized extension of the communication distance by using repeaters, and the further authentication is carried out.

Abstract: An integrated circuit is combined with a transponder to function either as a voltage or power supply for the transponder by extracting energy out of an electromagnetic field transmitted by a base station or as a detector in the transponder to act as a remote sensor. For this purpose the integrated circuit comprises diode rectifiers. Each of the diode rectifiers has a first and a second service terminal and a reference terminal. In order to reduce a parasitic impedance between the first service terminal and the reference terminal, the first service terminal of at least one rectifier diode is electrically connected to a reference potential such as ground. Parasitic diode characteristics are further reduced by surrounding the respective diode or diodes by an electrical conductor path also connected to the reference potential.

Abstract: An integrated circuit can be tested externally at its normal signal output pin(s) without requiring additional testing output pins or test measuring pads. The integrated circuit includes a circuit unit that generates a normal output signal provided to the signal output pin in a normal operating mode and generates a test signal in a testing mode, a switching element that selectively does or does not connect the test signal from the circuit unit to the signal output pin, and a control unit that controls the switching element with a control signal responsive to the potential level present at the signal output pin. When the circuit is to be tested, a defined voltage is applied to the signal output pin by a voltage divider formed of resistors between a supply voltage and a reference voltage. This causes the control unit to close the switching element.

Abstract: A d.c. signal controlled oscillator includes a frequency-determining network having a control input and a modulation input. A phase regulating loop includes the oscillator and components that provide a control signal to the control input. A circuit apparatus for driving the oscillator includes a modulation generator that provides a modulation signal to the modulation input, and a circuit arrangement that autonomously generates a signal depending on and representing a slope of the modulation and provides this slope signal to the modulation generator, which generates the modulation signal dependent on the slope signal.

Abstract: A circuit arrangement for reducing the decay and build-up transient times of an intermittently operating oscillating circuit increases the data transmission rate of a transmission unit using such an oscillating circuit. A control unit is connected to the oscillating circuit including a capacitor, a coil, and a resistor. A switch element controlled by the control unit selectively connects a voltage source to the capacitor, or selectively connects a current source to the coil. In the former case, another switch element selectively disconnects the capacitor from the coil and the resistor. In this circuit arrangement the current and/or the voltage are maintained when the excitation voltage for the oscillating circuit is interrupted. This eliminates the decay of the oscillating circuit amplitudes. When the excitation voltage is switched on again, the oscillating circuit continues oscillating without delay.

Abstract: In a new process of making a DMOS transistor, the doping of the sloping side walls can be set independently from the doping of the floor region in a trench structure. Furthermore, different dopings can be established among the side walls. This is achieved especially by a sequence of implantation doping, etching to form the trench, formation of a scattering oxide protective layer on the side walls, and two-stage perpendicular and tilted final implantation doping. For DMOS transistors, this achieves high breakthrough voltages even with low turn-on resistances, and reduces the space requirement, in particular with regard to driver structures.

Abstract: A circuit includes a second switching unit, a first switching unit that is connected to and selectively actuates the second switching unit, and a capacitive voltage divider including first, second and third capacitances connected in series. The first and second switching units are connected respectively to first and second junctions between the first and second and the second and third capacitances respectively. An associated method involves applying a supply voltage to the voltage divider so as to charge the first and second junctions, discharging the first junction through the first switching unit, which, dependent on the voltage of the first junction, selectively actuates the second switching unit to supply an additional charging current to the second junction. A time-limited signal such as a power-on reset signal is tapped from the first or second switching unit or from the second junction. Thereafter, the circuit draws no further current.

Abstract: In a new process of making a DMOS transistor, the doping of the sloping side walls can be set independently from the doping of the floor region in a trench structure. Furthermore, different dopings can be established among the side walls. This is achieved especially by a sequence of implantation doping, etching to form the trench, formation of a scattering oxide protective layer on the side walls, and two-stage perpendicular and tilted final implantation doping. For DMOS transistors, this achieves high breakthrough voltages even with low turn-on resistances, and reduces the space requirement, in particular with regard to driver structures.

Abstract: A circuit arrangement for detecting a received signal includes a rectifier with an input connected to a receiving antenna for rectifying an encoded received signal, a signal capacitor connected to an output of the rectifier, a discharge current sink connected to the signal capacitor, and a signal evaluating circuit connected to the signal capacitor. The discharge current sink includes a current mirror circuit of cascode-connected transistors. Thereby, the discharge current is substantially independent of the signal voltage over a larger range of voltages. This signal detection circuit is useful in transponders or remote sensors that receive and detect a signal transmitted by a base station.

Abstract: A circuit arrangement for deriving electrical power from a received electromagnetic field to power a transponder includes a detuning unit connected between two antenna terminals for limiting the power absorbed by the antenna. The detuning unit includes a component having an impedance that passively varies or is actively varied dependent on the field strength of the field prevailing at the antenna. One arrangement of the detuning unit includes two varactor diodes connected anti-parallel between the antenna terminals. Another arrangement of the detuning unit includes a varactor arranged in series between two capacitors between the antenna terminals, a field strength detector, and a controllable voltage source connected to apply to the varactor a control voltage that varies depending on the detected field strength. Thereby, the input impedance varies depending on the field strength, to achieve impedance matching for a low field strength, and a mis-matched condition for a high field strength.

Abstract: For transmitting data, a receiving/backscattering arrangement receives, modulates and reflects or backscatters electromagnetic waves emitted by a base station. The modulation corresponds to the data to be transmitted and is carried out selectively using first and/or second different modulation methods depending on the received field strength of the received electromagnetic waves. Preferably, phase shift keying is used especially or at least at low field strengths at far range, while amplitude shift keying is used additionally or alternatively for high field strengths at close range. The two modulation methods can be superimposed. A circuit arrangement includes two different modulator arrangements to perform the two modulation methods depending on the received field strength. The second modulator arrangement preferably comprises a multi-stage voltage multiplier circuit with a modulated switching device intervening in one of the stages to achieve the modulation.

Abstract: An SOI wafer includes a substrate, and an insulating intermediate layer and a surface layer successively thereon. At least one laterally limited suicide area is formed in and/or on the surface layer. Then an oxide layer is provided on the surface layer of the SOI wafer and/or on a second silicon wafer, before the two wafers are bonded to each other along the oxide layer. The substrate and the insulating intermediate layer are removed to leave a bonded multi-layered wafer. At least one device component is fabricated in and/or on the surface layer to include the silicide area as a functional element of the device component. Different types of components, e.g. MOS and bipolar transistors, can be fabricated together on the same wafer, and HF characteristics are improved by the low ohmic suicide area(s).

Abstract: A high frequency power detector includes an input coupling arrangement that couples an electrical HF-oscillation into a basic circuit portion including at least a first diode and a circuit node. The power detector further includes a series circuit of a resistor and a second diode connected to the circuit node, as well as a voltage tapping arrangement for detecting or tapping the voltage drop across the second diode as an output signal. The voltage at the circuit node includes a DC component that depends on the power of the HF-oscillation. The output signal, i.e. the voltage drop of the second diode, has a linear voltage characteristic relative to the HF-power in dBm. A method of regulating the HF-power uses such a dBm-linear HF-power detector in a feedback loop for regulating the gain factor of an HF-amplifier.

Abstract: A manufactured multi-layered silicon wafer with a buried insulating layer and buried areas with different parameters is formed by bonding together a first wafer and a second wafer. Before the bonding, areas with modified layer parameters, which will be buried by bonding with the second wafer, are created on the surface of the first wafer, which also has an insulating intermediate layer. A further insulating layer is then applied, and the surface of the first wafer is bonded to the surface of the second wafer. The substrate layer and the insulating intermediate layer of the first wafer are subsequently removed. This eliminates the conventional thinning of the second wafer. In addition, areas with vertical gradients can be created in the layer parameters without processing the second wafer.

Abstract: In a method for manufacturing a silicon wafer with an insulating intermediate layer, the surface of a first wafer, which has an insulating intermediate layer, is bonded to the surface of a second wafer, and then the substrate layer and the insulating intermediate layer of the fist wafer are removed. The new silicon surface created in this manner has a high layer quality which is achieved at a low cost.

Abstract: A circuit includes two internal current sources or sinks coupled together by a coupling element, which may be a direct junction as a summing element or a current mirror as a subtracting element. In an associated method, the currents of the two internal current sinks or sources are summed or subtracted by the coupling element to form an output current. The magnitudes and/or temperature coefficients of the two internal currents differ from one another. The temperature coefficient of the output current is determined by the addition or subtraction of the internal currents, and can be selected as desired, simply and economically, by appropriately selecting the temperature coefficients of the internal currents and the adding or subtracting carried out by the coupling element. The output current can even have a negative temperature coefficient, based on economical internal components having only positive temperature coefficients.

Abstract: For transmitting data between a base station and a transponder, information packets modulated onto an electromagnetic carrier wave each include a header section, a middle section, and an end section. The data are encoded in the middle section using information symbols, e.g. representing digital “1s” and “0s”. The header section of at least the first packet defines the number and unique identifications of all of the symbols that will be used for encoding the data in the middle section of this and/or subsequent packets. This transmission protocol defined in the header section can be varied in subsequent packets to adaptively adjust the transmission rate depending on the existing communication conditions and requirements such as high frequency regulations prescribed by national law. The transmission rate can be considerably increased, in comparison to a transmission rate that would otherwise be necessary for achieving a reliable transmission even under unfavorable conditions.