A plurality of Phase Locked Loops, PLL (12, 14), are distributed across an Integrated Circuit, each receiving a common reference signal (A). A local phase error (B) of each PLL (12, 14) is connected to a phase error averaging circuit (16), which calculates an average phase error (C), and distributes it back to each PLL (12, 14). In each PLL (12, 14), two loop filters (20, 22) with different bandwidths are deployed. A lower bandwidth, high DC gain, common mode loop operates on the average phase error, and forces the PLL outputs (H) to track the phase of the common reference signal. A high bandwidth, difference mode loop operates on the difference between the local phase error (B) and the average phase error (C) to suppress phase differences between PLL outputs, minimizing interaction between them. The reference noise contribution at the output is controlled by the common mode loop, which can have a low bandwidth. The reference noise contribution and oscillator interaction suppression are thus independently controlled.

A plurality of Phase Locked Loops, PLL (12, 14), are distributed across an Integrated Circuit, each receiving a common reference signal (A). A local phase error (B) of each PLL (12, 14) is connected to a phase error averaging circuit (16), which calculates an average phase error (C), and distributes it back to each PLL (12, 14). In each PLL (12, 14), two loop filters (20, 22) with different bandwidths are deployed. A lower bandwidth, high DC gain, common mode loop operates on the average phase error, and forces the PLL outputs (H) to track the phase of the common reference signal. A high bandwidth, difference mode loop operates on the difference between the local phase error (B) and the average phase error (C) to suppress phase differences between PLL outputs, minimizing interaction between them. The reference noise contribution at the output is controlled by the common mode loop, which can have a low bandwidth. The reference noise contribution and oscillator interaction suppression are thus independently controlled.

An FMCW radar transmission and reception apparatus radiates, via a transmission antenna, a beat frequency signal of a frequency modulation continuous wave (FMCW) and then receives, via a reception antenna, a reflected signal obtained from the radiated frequency modulation continuous wave (FMCW) signal that is reflected by a target and returns, wherein the frequency of a beat signal of a frequency modulation continuous wave (FMCW) radar can be effectively adjusted by configuring a plurality of phase locked loops (PLLs) used in a transmitter and a receiver, and using the same reference oscillation signal for the plurality of PLLs.

In a particular implementation, a method to reduce noise/clock jitter and to generate a “stretched” output clock to optimize for jitter of the output clock is disclosed. The method includes: generating two or more clock phases upon detecting a transient voltage by a detector circuit, generating an output clock signal based on one of the two or more clock phases; and altering a phase speed of the output clock signal to correspond to a phase speed of an input clock signal.

An IC, operable at a first clock phase, includes first and second IOs and a PLL. The PLL includes a control circuit, an input to receive a first clock signal, an output to output a second clock signal, and a first detector to generate a first phase difference signal from the first and second clock signals. The IC includes a second phase detector that is coupled to the PLL's output to receive the second clock signal and is coupled to the first IO to receive a third clock single from a second IC, which is operable at a second clock phase. The second detector generates a second phase difference signal from the second and third clock signals. If the PLL uses the second phase difference signal to generate the second clock signal, then the second clock signal is synchronized with the third clock signal for synchronous data transfer.

An IC, operable at a first clock phase, includes first and second IOs and a PLL. The PLL includes a control circuit, an input to receive a first clock signal, an output to output a second clock signal, and a first detector to generate a first phase difference signal from the first and second clock signals. The IC includes a second phase detector that is coupled to the PLL's output to receive the second clock signal and is coupled to the first IO to receive a third clock single from a second IC, which is operable at a second clock phase. The second detector generates a second phase difference signal from the second and third clock signals. If the PLL uses the second phase difference signal to generate the second clock signal, then the second clock signal is synchronized with the third clock signal for synchronous data transfer.

Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

A clock generating circuit includes a first frequency multiplier configured to generate a second clock signal having a second frequency based on a first clock signal having a first frequency, and a second frequency multiplier configured to generate a third clock signal having a third frequency based on the second clock signal. The first frequency multiplier includes a circuit configured to control a duty cycle of the first clock signal, a delay circuit configured to receive the duty controlled clock signal, and delay the received signal based on a duty cycle of the second clock signal to output a first delay clock signal, and an XOR gate configured to perform an XOR computation using the duty controlled clock signal and the first delay clock signal to output the second clock signal. The second frequency is greater than the first frequency, and the third frequency is greater than the second frequency.

A signal generating electric circuit, a signal generating method, a digit-to-time converting electric circuit and a digit-to-time converting method. The signal generating electric circuit includes: a first generating electric circuit configured for, based on a first frequency control word and a reference time unit, generating a periodic first output signal; and a second generating electric circuit configured for, based on a second frequency control word and the reference time unit, generating a periodic second output signal. The first frequency control word includes a first integer part and a first fractional part, the second frequency control word includes a second integer part and a second fractional part, the first integer part is equal to the second integer part, the first fractional part is not zero, the second fractional part is zero, and a period of the first output signal and a period of the second output signal are not equal.

A dual-output microelectromechanical system (MEMS) resonator can be operated selectively and concurrently in an in-plane mode of vibration and an out-of-plane mode of vibration to obtain, respectively, a first electrical signal having a first frequency and a second electrical signal having a second frequency that is less than the first frequency. The first and second electrical signals are mixed to obtain a third electrical signal having a third frequency, where the third frequency is proportional to a temperature of the MEMS resonator. The temperature is determined based on the third frequency. Values of the first and second frequencies can be adjusted based on the determined temperature to compensate for frequency deviations due to temperature deviations. Also described herein are methods and systems for determining the temperature of the dual-output MEMS and for performing frequency compensation, as well as a method of manufacturing the dual-output MEMS.