Abstract: An all digital PLL system generates an analog oscillator signal at intermediate frequencies to achieve averaged oscillator frequencies at an extremely high frequency resolution. The PLL system includes a digitally controlled oscillator (10) with a digital control input and an analog signal output, and a feedback loop with a digital loop filter (16) for generating a digital control signal for the digitally controlled oscillator (10). The digital loop filter (16) has a first output providing an integer part (nint) of the digital control signal and a second output providing a fractional part (n??) of the digital control signal.

Abstract: An all digital PLL system generates an analog oscillator signal at intermediate frequencies to achieve averaged oscillator frequencies at an extremely high frequency resolution. The PLL system includes a digitally controlled oscillator (10) with a digital control input and an analog signal output, and a feedback loop with a digital loop filter (16) for generating a digital control signal for the digitally controlled oscillator (10). The digital loop filter (16) has a first output providing an integer part (nint) of the digital control signal and a second output providing a fractional part (n??) of the digital control signal.

Abstract: In a circuit assembly for generating pulses sustaining or “plucking” RF oscillations in a resonant circuit (12) of transponder (10) having no battery power supply in which the supply voltage needed for its operation is obtained from a RF carrier oscillation pulse defined in time exciting the resonant circuit into oscillation and used to charge a storage element whose charging voltage forms the supply voltage, a plucking pulse is generated every time the amplitude of the RF oscillations drops below a defined threshold value and its momentary value is in a defined relationship to a reference voltage (VPEAK) changing in time as the charging voltage of a capacitor (70). A switch (24) is provided which can be switched on for the duration of the plucking pulse (PLUCK) for connecting the storage element (20) to the resonant circuit (12).

Abstract: In a circuit assembly for generating pulses sustaining or “plucking” RF oscillations in a resonant circuit (12) of transponder (10) having no battery power supply in which the supply voltage needed for its operation is obtained from a RF carrier oscillation pulse defined in time exciting the resonant circuit into oscillation and used to charge a storage element whose charging voltage forms the supply voltage, a plucking pulse is generated every time the amplitude of the RF oscillations drops below a defined threshold value and its momentary value is in a defined relationship to a reference voltage (VPEAK) changing in time as the charging voltage of a capacitor (70). A switch (24) is provided which can be switched on for the duration of the plucking pulse (PLUCK) for connecting the storage element (20) to the resonant circuit (12).

Abstract: A full-wave rectifier circuit (70) includes a first transistor (N1) and a second transistor (N2) in combination to form a first transistor pair (N1 and N2) for minimizing the voltage drop between ground (88) and the transponder substrates. A third transistor (P1) and a fourth transistor (P2) operate in combination to form a second transistor pair (P1 and P2) for minimizing the voltage drop between the alternating current peak voltage (118 and 120) and the output voltage (V.sub.DD) of the full-wave rectifier (70). The first transistor pair (N1 and N2) and second transistor pair (P1 and P2) are controlled by alternating current voltage input signals (118 and 120). A series regulator circuit (70) decouples the first transistor pair (N1 and N2) and the second transistor pair (P1 and P2) from capacitive loads (C1 and C2) of the full-duplex transponder circuitry (14).