Abstract:
The invention relates to a resonator circuit (100), the resonator circuit (100) comprising a transformer (101) comprising a primary winding (103) and a secondary winding (105), wherein the primary winding (103) is inductively coupled with the secondary winding (105), a primary capacitor (107) being connected to the primary winding (103), the primary capacitor (107) and the primary winding (103) forming a primary circuit, and a secondary capacitor (109) being connected to the secondary winding (105), the secondary capacitor (109) and the secondary winding (105) forming a secondary circuit, wherein the resonator circuit (100) has a common mode resonance frequency at an excitation of the primary circuit in a common mode, wherein the resonator circuit (100) has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode, and wherein the common mode resonance frequency is different from the differential mode resonance frequency.
Abstract:
The invention relates to a discrete-time filter for filtering an input signal, the discrete-time filter comprising a switched capacitor network, the switched capacitor network comprising an input (102) and an output (104), a number of switched capacitor paths (101, 103, 105, 107) arranged in parallel between the input (102) and the output (104), each switched capacitor path (101, 103, 105, 107) comprising a capacitor, and a switch circuitry (121, 125, 127) for switching each capacitor at a different time instant for outputting a filtered input signal.
Abstract:
Time-to-digital converter system comprising: an event detector configured for detecting an event and generating an event detection signal upon detection of the event;and a time-to-digital converter coupled or connectable to the event detector and comprising a fine resolution part configured for counting fine time intervals, organized such that the fine resolution part is activated in response to the event detection signal and deactivated in response to a reference clock. 3D imager comprising an array of pixels, with in each pixel such a time-to-digital converter system, and further comprising a reference clock generator.
Abstract:
A charge sharing filter (303) includes: a rotating capacitor (C R ); and a plurality of elementary filters (311, 312, 313), each elementary filter comprising: an elementary switch (φ,) coupled between a first node (A i ) of the respective elementary filter and a second node (B i ) of the respective elementary filter; and a history capacitor (C H ) coupled to the first node (A i ) of the respective elementary filter, wherein the second nodes (B i ) of the plurality of elementary filters are interconnected with the rotating capacitor (C R ) in one interconnecting node (B).
Abstract:
The invention relates to a superheterodyne receiver (100), comprising: a sampling mixer (101) being configured to sample an analogue radio frequency signal (102) using a predetermined sampling rate (fs) to obtain a discrete-time sampled signal (104), and to shift the discrete-time sampled signal (104) towards a first intermediate frequency (|f RF -f LO |) to obtain an intermediate discrete-time signal (108) sampled at the predetermined sampling rate (fs); a discrete-time filter (103) being configured to filter the intermediate discrete-time signal (108) at the predetermined sampling rate (fs) to obtain a filtered signal (130); and a discrete-time mixer (109) being configured to shift the filtered signal (130) towards a second intermediate frequency (f IF ).
Abstract:
Disclosed are methods, circuits and systems for image reject filtering in a multi-tap direct sampling mixer (MTDSM) of an IF or RF system. Disclosed is the use of rotating capacitors among the in-phase and quadrature branches of a signal processing system. The exchange of information among the branches of the I and Q channels is used in the implementation of a complex filter. Rotation of a switched capacitor C R between the I and Q channels of the circuit causes a sharing of the charge among the four paths, I+, I-, Q+, Q-, resulting in a direct sampling and a complex filtering arrangement (10). The preferred embodiment of the filter (10) shown can be seen to have four sub-circuits (12, 14, 16, 18), which may be understood as single-pole IIR filters. Embodiments using cascaded multiple stages of the complex filter to provide higher order complex filters are also disclosed.
Abstract:
When a sample stream is decimated, frequency components from outside of a desired frequency band are aliased into the desired band, causing interference and loss of information. Different decimating ratios result in different frequencies aliasing into the desired frequency band. A current-mode sampling mixer (800) with capacitor banks (811) and (812) that are controlled by a digital control unit (820) with a capability to integrate and decimate an RF current at different decimating ratios is able to measure the frequency spectrum with different decimating ratios. The measured frequency spectrum is then analyzed to detect the presence of interferers aliased into the desired frequency band. The interferers can then be eliminated or avoided.
Abstract:
A time register (300) includes: a pair of inputs (345, 346) coupled to a pair of input clocks (IN 1 , IN 2 ); a pair of tri-state inverters (301, 302) for producing a pair of level signals (V C1 , V C2 ); and a pair of outputs (347, 348) coupled to the level signals (V C1 , V C2 ) for producing a pair of output clocks (OUT 1 , OUT 2 ), wherein the tri-state inverters (301, 302) are responsive to a pair of state signals (S 1 , S 2 ) and the pair of input clocks (IN 1 , IN 2 ) for holding or discharging the level signals (V C1 , V C2 ).
Abstract:
A transformer (400) includes: a primary winding (401) comprising a first port (401a), a second port (401b) and a metal layer (413) connected between the first port (401a) and the second port (401b), the metal layer (413) comprising a plurality of sections (Z 1 /θ 1 , Z 2 /θ 2 , Z 3 /θ 3 , Z 4 /θ 4 ) of different electrical lengths and/or characteristic impedances; and a secondary winding (402) electromagnetically coupled with the primary winding (401), the secondary winding (402) comprising a first port (402a), a second port (402b) and a metal layer (423) connected between the first port (402a) and the second port (402b), the metal layer (423) comprising a plurality of sections (Z 5 /θ 5 , Z 6 /θ 6 , Z 7 /θ 7 , Z 8 /θ 8 , Z 9 /θ 9 , Z 10 /θ 10 ) of different electrical lengths and/or characteristic impedances.
Abstract:
The invention relates to a radio frequency oscillator (100), the radio frequency oscillator (100) comprising a resonator circuit (101) being resonant at an excitation of the resonator circuit (101) in a differential mode and at an excitation of the resonator circuit (101) in a common mode, wherein the resonator circuit (101) has a differential mode resonance frequency at the excitation in the differential mode, and wherein the resonator circuit (101) has a common mode resonance frequency at the excitation in the common mode, a first excitation circuit (103) being configured to excite the resonator circuit (101) in the differential mode to obtain a differential mode oscillator signal oscillating at the differential mode resonance frequency, and a second excitation circuit (105) being configured to excite the resonator circuit (101) in the common mode to obtain a common mode oscillator signal oscillating at the common mode resonance frequency.