Abstract:
A phase detector (100, 400, 800) comprising a balun (150) and input ports (116) at each of the balun's balanced ports. The phase detector (100, 400, 800) has four devices (105, 115, 110, 155) for measuring a signal's amplitude: - a first device (105) at a first input port (116), - a second device (115) at a second input port (117), - a third device (110) between the input ports (116, 117), connected to the ports via a passive component (120, 125; 120', 125'; 120", 125"), - a fourth device (155) at the unbalanced port of the balun (150), The difference between the amplitude values of the third (110) and fourth (155) devices indicate the phase difference and the difference between the amplitude values measured by the first (110) and second (115) devices indicates the phase difference in the region of 0-2π.
Abstract:
It is described an electronic device for generating a fractional synthesized frequency. The device comprises a multi-phase controlled oscillator adapted to generate, from a control signal, a plurality of signals phase-shifted each other and comprises a phase detector adapted to receive a selected signal from the plurality of phase-shifted signals, to receive a reference signal and to measure a difference between a phase of the selected signal and a phase of the reference signal. The electronic device further comprises control means for estimating, from the measured phase difference, a phase error affecting the generation of at least one of the plurality of phase-shifted signals, and for generating a corrected measure of the phase difference taking into account the estimated phase error, the corrected measure being used to provide the control signal.
Abstract:
A phase-frequency detector (110) is provided. The phase-frequency detector can include a frequency counter delay (147) for counting cycles of an output signal to generate a divided variable frequency delayed signal (FVd 146) having a time shift. A control stage (200) coupled to the output stage generates a pump up control signal (222) and a pump down control signal (234) in response to receiving the FVd signal, a divided variable frequency signal (FV 136), and a reference frequency signal (FR 106). The time shift provides an overlap region that allows both source (350) and sink (360) currents to be provided in phase lock. In phase lock, the duration of the pump up control signal approximates the duration of the pump down control signal within a linear region of operation.
Abstract:
Digital transmitters having improved characteristics are described. In one design of a digital transmitter, a first circuit block receives inphase and quadrature signals, performs conversion from Cartesian to polar coordinates, and generates magnitude and phase signals. A second circuit block (which may include a delta-sigma modulator or a digital filter) generates an envelope signal based on the magnitude signal. A third circuit block generates a phase modulated signal based on the phase signal. The third circuit block may include a phase modulating phase locked loop (PLL), a voltage controlled oscillator (VCO), a saturating buffer, and so on. A fourth circuit block (which may include one or more exclusive-OR gates or an amplifier with multiple gain states) generates a digitally modulated signal based on the envelope signal and the phase modulated signal. A fifth circuit block (which may include a class D amplifier and/or a power amplifier) amplifies the digitally modulated signal and generates an RF output signal.
Abstract:
A tracking circuit (100) is provided for controlling a locally-generated clock. A receive channel (110) in the tracking circuit receives an incoming signal and a local clock, generates a local signal based on the local clock, and compares the local signal and the incoming signal to generate a data signal and an unfiltered phase error signal. A loop filter (120) filters the unfiltered phase error signal to provide a filtered phase error signal. A numerically controlled oscillator (140) generates a correction clock based on the filtered phase error signal. And a filter control circuit (160) provides one or more filter control signals to control operational parameters of the loop filter. The correction clock is provided to the receive channel to modify at least one of the phase and frequency of the local clock. In addition, a sample switch (125) may also be provided to sample the unfiltered phase error signal.
Abstract:
Linear phase detectors comprising circuits (1,2) receiving reference signals (REF) and first and second clock signals (CLK-Q, CLK-I) for generating first and second (phase) control signals (UP,DOWN) for use in multiplier circuits, demodulators and receivers, have large delays due to long path lengths and many operations between input and output (insight). They can be made faster by providing each circuit (1,2) with two parallel latches (10,11,20,21) and a multiplexer (12,22) for multiplexing latch output signals (basic idea). Said multiplexers generate (frequency control) signals to be supplied to frequency detectors, with a third circuit (3) generating at least one of said (phase) control signals (UP,DOWN). Said third circuit (3) comprises a latch (30) generating said first (phase) control signal (UP), with one of the latches (20) of the second circuit (2) generating the second (phase) control signal (DOWN). Or said third circuit (3) comprises logical circuitry (31-34) comprising four EXOR gates (31-34). A fifth EXOR gate (35) is used for balancing the third circuit (3).
Abstract:
Frequency detector systems (1) comprise phase detector systems (11) for, in response to data signals, generating Q-phase signals and I-phase signals, and comprise frequency detectors (10) for, in response to Q-phase signals and I-phase signals, generating frequency control signals. To avoid idling frequency control signals (insight), tri-state frequency control signals are generated comprising a first or second value in a non-lock situation and comprising a third value in a lock situation (basic idea). This improves the efficiency and the performance of the frequency detector system (1). Said frequency detector (10) comprises a sampling stage (20) like a latch (22) and a converting stage (21) comprising transistors (23,24,25,26). Said phase detector system (11) comprises two half-rate phase detectors (30,3 1) each comprising three circuits each comprising two latches (40,41,43,44,46,47) and a multiplexer (42,45,48).