摘要:
A sigma-delta converter has a signal input for receiving a data word. A clock signal input is designed to supply a clock signal. The sigma-delta converter includes a first clocked-operation accumulator stage whose input side is connected to the signal input, and at least one second clocked-operation accumulator stage connected in series with the first accumulator stage, with its input side coupled to an accumulator output of the first accumulator stage. The sigma-delta converter is configured to process the data word upon each clock signal only in one accumulator stage in the first and the at least one second accumulator stage, and output the processed data word at the accumulator output of the one accumulator stage. As a result, a time-critical response during signal processing is limited just to the accumulator stage which is currently processing the data word.
摘要:
The invention is directed to a phase locked loop with a ΣΔ modulator. A multimodulus divider in the feedback path of the PLL is actuated by the ΣΔ modulator. The latter has a design which can be described by a complex transfer function H(s) in the Laplace plane, said transfer function having a complex-conjugate pair of pole points. The arrangement allows a significant reduction in the noise in critical frequency domains and hence allows adherence to transmission masks based on radio specification even when the PLL bandwidth is as large as the modulation bandwidth.
摘要:
A VCO circuit (20) has a coil (21) and, in parallel therewith, a constant capacitance (24) and adjustable capacitance elements (22, 23). A first capacitance element (22) is formed by one or more varactors whose capacitance can be adjusted by an analogue adjusting voltage (Vtune), while a second capacitance element (23) is formed by an arrangement comprising a plurality of capacitors which can be actuated by a digital bit word VCWD[N:1]. Digital calibration for the VCO (20) is performed by determining whether the present adjusting voltage is within a particular voltage range and, if this is not the case, the digital bit word being incremented or decremented by a bit value.
摘要:
The phase locked loop according to the invention has an adjustable charge pump (2) which is intended to generate a control voltage (UVCO). A voltage-controlled oscillator (4) and an evaluation unit (14) are connected downstream of said charge pump. In this case, the evaluation unit (14) is designed in such a manner that it can be used to generate a correction signal (Iref) using the control voltage (UVCO) and a nominal gradient ({circumflex over (K)} vco) of the voltage-controlled oscillator (4) and to apply said signal to the evaluation output. The latter is, in turn, connected to an input of the charge pump (2).
摘要:
A first signal path having an amplifier and a second signal path having an amplifier with adjustable gain factor are provided. A signal applied to the first and second signal paths is amplified and demodulated on the first signal path. Concurrently, the signal is amplified on the second signal path with a gain factor, and a power of the signal amplified by the second signal path is determined and used for determining the gain factor. A signal conditioning circuit has first and second signal paths and a first and a second operating state. In the first operating state, the first signal path is arranged for amplification for a demodulation, and the second signal path is arranged for amplification for determination of a power of the signal present. In the second operating state, one of the two signal paths is inactive and the other is arranged for demodulating the signal present.
摘要:
A polar modulator contains a phase locked loop which is designed to emit a radio-frequency signal at one frequency to one output, with the frequency being derived from the reference signal and from a phase modulation signal at a control input of the phase locked loop. The modulator additionally has a second signal input for supplying an amplitude modulation signal. The second signal input is connected to a control input of a pulse width modulator, one of whose signal inputs is coupled to the output of the phase locked loop. The pulse width modulator is designed to vary the duty ratio of a signal which is applied to the signal input, with this variation being adjustable via a regulation signal at the control input. A filter can be connected downstream from the output of the pulse width modulator and suppresses higher harmonic components in a signal which can be tapped off at the output of the pulse width modulator. The amplitude of an output signal is thus modulated by carrying out pulse width modulation and by subsequent suppression of higher-level frequency components.
摘要:
The invention is directed to a phase locked loop with a ΣΔ modulator. A multimodulus divider in the feedback path of the PLL is actuated by the ΣΔ modulator. The latter has a design which can be described by a complex transfer function H(s) in the Laplace plane, said transfer function having a complex-conjugate pair of pole points. The arrangement allows a significant reduction in the noise in critical frequency domains and hence allows adherence to transmission masks based on radio specification even when the PLL bandwidth is as large as the modulation bandwidth.
摘要:
A method and an arrangement for processing a received signal which comprises phase-shift modulated or amplitude-quadrature modulated part-signals which are transmitted in a plurality of different frequency bands, wherein the received signal is processed in a plurality of stages in succession, by multiplying all the input signals to each of the stages by two mutually orthogonal signals in each case to form two intermediate signals in each case, wherein the intermediate signals from one stage in each case act as the input signals to whichever is the succeeding stage in the particular case and the received signal acts as the input signal to the first stage, and wherein an in-phase and/or an quadrature component of the individual part-signals in the different frequency bands are determined from the intermediate signals from the last stage. Parallel, simultaneous reception of a plurality of frequency bands can be implemented relatively easily in this way.
摘要:
An arrangement for testing a plurality of capacitances in a capacitance array of an integrated circuit includes a power supply and a means for cyclically charging and discharging at least one of the capacitances. In this arrangement, the cycle frequency is dependent on the value of the capacitance. The cycle frequency or a quantity characteristic associated therewith is measured by a means to ascertain a value of the capacitance under test.
摘要:
The invention discloses a signal conditioning circuit having a vector demodulator for breaking down a signal applied to the input into a first component and a second component. The outputs of the vector demodulator having at least one first amplifier circuit comprising a first and a second input connected thereto which may be configured to amplify signals applied to the input using an adjustable gain. The outputs of the at least one first amplifier circuit are connected to a first analog/digital converter. A polyphase filter may be connected between outputs of the vector demodulator and the input of the first amplifier circuit. The polyphase filter has an adjustable filter bandwidth.