A local oscillator (LO) circuit includes a voltage controlled oscillator (VCO) configured to receive an output of a phase locked loop (PLL) circuit, the VCO coupled to a clock gating circuit configured to generate a VCO output signal (vco_g), a local oscillator (LO) divider configured to receive the VCO output signal (vco_g) and a local oscillator (LO) preset signal, the LO preset signal configured to set the LO divider to a predetermined initial phase, a programmable divider configured to receive a divider signal and the VCO output signal (vco_g) and generate a local oscillator (LO) phase detection trigger signal, Fv, a toggling accumulator coupled to an output of the programmable divider, the toggling accumulator configured to receive the divider signal and the LO phase detection trigger signal, Fv, and generate a counter signal, and a decision logic configured to receive a sample enable signal and the counter signal and adjust the programmable divider based on the sample enable signal and the counter signal.

Various embodiments implement apparatuses and methods for conversion of radio frequency (RF) signals to intermediate frequency (IF) signals. More particularly, some embodiments are directed toward down conversion of RF signals to IF signals in a multi-band radio receiver, such as a satellite receiver, using a single oscillator for different frequency bands. For example, some of the apparatuses and methods presented are suitable for integration into monolithic RF integrated circuits in low-cost satellite receivers for home entertainment use.

Various embodiments implement apparatuses and methods for conversion of radio frequency (RF) signals to intermediate frequency (IF) signals. More particularly, some embodiments are directed toward down conversion of RF signals to IF signals in a multi-band radio receiver, such as a satellite receiver, using a single oscillator for different frequency bands. For example, some of the apparatuses and methods presented are suitable for integration into monolithic RF integrated circuits in low-cost satellite receivers for home entertainment use.

A digital sine wave may be converted to an analog signal at a digital to analog converter (DAC). The converted analog signal may be supplied to a device and an analog return signal from the device may be passed through a relaxed anti-aliasing filter and converted to digital code words at an analog to digital converter (ADC). An impedance may be calculated from the results of a Fourier analysis of the digital code words. The ADC and DAC clock frequencies may be asynchronous, independently variable, and have a greatest common factor of 1. The clock frequencies of the ADC and/or DAC may be adjusted to change a location of images in the ADC spectrum. By using these different, adjustable clock frequencies for the ADC and the DAC, an analog signal may have increased aliasing without introducing signal errors at a frequency of interest.

Aspects of the disclosure include an integrated circuit that includes a first circuit, a first performance detector, and a first regulator. The first circuit is configured to receive a first regulated voltage from a first voltage supply line disposed on the integrated circuit. The first performance detector includes a first speed monitor disposed adjacent to the first circuit, and the first performance detector is configured to generate a first control signal based on a first speed detection result from the first speed monitor. The first speed detection result corresponds to measuring an operational speed of the first circuit. The first regulator is configured to receive a global supply voltage from a power rail and output the first regulated voltage based on the global supply voltage and the first control signal.

A frequency doubler (tripler, or quadrupler) employs current re-use coupled oscillator technique to enhance phase noise without increasing current consumption. Frequency doubler uses coupling between two oscillators running at different frequencies; a first oscillator is running at the target frequency and a second oscillator is running at half the frequency. The coupling between the two oscillators is via a transformer having a primary transformer coil and a secondary transformer coil. The first oscillator comprises a differential inductor, coarse/fine tuning capacitor arrays, and an n-type trans-conductor (GM). A virtual ground node of the n-type GM is coupled to one side of the primary transformer coil and the other side of the primary coil is coupled to the center tap of the secondary coil. The second oscillator comprises the secondary coil, coarse/fine tuning capacitor arrays, n-type GM, frequency tracking loop (FTL) and 2.sup.nd-harmonic LC filter network.

A phase-variable frequency multiplier includes: a 90-degree divider for dividing an input signal into an I-signal and a Q-signal; an amplitude setting circuit for distributing each of the I-signal and the Q-signal to two paths, setting amplitudes of two of four signals including the two distributed I-signals and the two distributed Q-signals depending on a phase shift amount of the input signal, and outputting as set signals, the four signals including the signals with the set amplitudes; a first mixer for multiplying one of the two I-signals included in the set signals by one of the two Q-signals included in the set signals to generate a first signal having a frequency being twice the frequency of the input signal; a second mixer for multiplying the other of the two I-signals included in the set signals by the other of the two Q-signals included in the set signals to generate a second signal with an amplitude ratio with respect to the first signal, being a tangent or a reciprocal of a tangent of the phase shift amount and with a frequency being twice the frequency of the input signal; and a 90-degree combiner for applying a phase difference of 90 degrees between the first signal and the second signal, and combining the first signal having the phase difference of 90 degrees from the second signal with the second signal.

Aspects of the disclosure relate to a local oscillator frequency divider for a receiver or transmitter. In this regard a frequency divider has a first frequency input coupled to a first oscillator frequency output, a second frequency input coupled to a complementary second oscillator frequency output, a first in-phase/quadrature (I/Q) divided frequency output, and a complementary second I/Q divided frequency output. The frequency divider further has a first alternating current (AC) coupling capacitor between the first frequency input and the first oscillator frequency output and a second AC coupling capacitor between the second frequency input and the second oscillator frequency output.

A circuit apparatus includes an oscillation circuit that generates an oscillation signal, a first buffer circuit that outputs a first clock signal based on the oscillation signal, a second buffer circuit that outputs a second clock signal based on the first clock signal, a first terminal electrically couplable to a first node via which the first buffer circuit outputs the first clock signal, and a second terminal electrically coupled to a second node via which the second buffer circuit outputs the second clock signal, and the rise period of the first clock signal is shorter than the rise period of the second clock signal.

A transposed delay line oscillator including a mode selection filter and a transposed delay line is provided. An output of the transposed delay line is coupled to an input of the mode selection filter to establish an oscillator loop. Based on the transposed delay line output, the mode selection filter generates a mode selection signal including an isolated oscillatory mode, in a Radio Frequency (RF) band. The transposed delay line receives the mode selection signal for transposition to an intermediate frequency of an intermediate frequency (IF) delay line. The IF delay line includes a delay filter and a phase noise suppression loop configured to suppress de-correlated transposition phase noise resulting from a delay of the delay filter. Suppression of phase noise in the IF delay line enables cancellation of transposition phase noise when transposing the IF delay line output to the RF band.