Abstract: An LC tank circuit, such as an LC tank circuit of a step-tuned voltage controlled oscillator, includes an inductor and one or more capacitors. The inductor can be dog-bone shaped with a body, an extension and a chamfered joint to improve current distribution. The body and the extension can extend along different directions. The body can be narrower than the extension, and the extension can be sufficiently wide to interface with a plurality of switched capacitor circuits coupled to different parts of the extension.

Abstract: An LC tank circuit, such as an LC tank circuit of a step-tuned voltage controlled oscillator, includes a plurality of switched capacitor banks and one or more inductors. A first switched capacitor bank switch in response to a range of control signals used to control the VCO output across a range of frequencies. A second switched capacitor bank can switch in response to a subset of the range of control signals used to control the VCO output across a subset of the range of frequencies. The control scheme for the first and second switched capacitor banks can improves the linearity of changes in the frequency of the output signal of the VCO.

Abstract: An LC tank circuit, such as an LC tank circuit of a step-tuned voltage controlled oscillator, includes a plurality of switched capacitor banks and one or more inductors. A first switched capacitor bank switch in response to a range of control signals used to control the VCO output across a range of frequencies. A second switched capacitor bank can switch in response to a subset of the range of control signals used to control the VCO output across a subset of the range of frequencies. The control scheme for the first and second switched capacitor banks can improves the linearity of changes in the frequency of the output signal of the VCO.

Abstract: An LC tank circuit, such as an LC tank circuit of a step-tuned voltage controlled oscillator, includes an inductor and one or more capacitors. The inductor can be dog-bone shaped with a body, an extension and a chamfered joint to improve current distribution. The body and the extension can extend along different directions. The body can be narrower than the extension, and the extension can be sufficiently wide to interface with a plurality of switched capacitor circuits coupled to different parts of the extension.

Abstract: Aspects of this disclosure relate to a first die includes an LC resonant circuit including a first capacitive element, such as a capacitor or a varactor, and an inductive element. The LC resonant circuit is configured to generate a signal having a frequency of oscillation. The first die includes bump pads electrically coupled to both ends of the first capacitive element. A second die can be flip chip mounted on the first die. Bumps can electrically connect a second capacitive element of the second die in parallel with the first capacitive element of the first die. This can increase the Q factor of the LC resonant circuit.

Abstract: A die is packaged by flip-chip mounting the die with the active side facing a low loss substrate. A ground plane is coupled to the active side of the die by vias through the low loss substrate. The ground plane is positioned to concentrate high frequency electromagnetic fields in the low loss substrate. A tuning height can be adjusted to tune the center frequency of a circuit in the die.

Abstract: Aspects of this disclosure relate to a first die includes an LC resonant circuit including a first capacitive element, such as a capacitor or a varactor, and an inductive element. The LC resonant circuit is configured to generate a signal having a frequency of oscillation. The first die includes bump pads electrically coupled to both ends of the first capacitive element. A second die can be flip chip mounted on the first die. Bumps can electrically connect a second capacitive element of the second die in parallel with the first capacitive element of the first die. This can increase the Q factor of the LC resonant circuit.

Abstract: A voltage controlled oscillator including an RF output terminal and a DC control terminal, an active circuit, and a resonant circuit interconnected with the active circuit and including a plurality of series resonators each having an electrically variable capacitance and fixed inductor; the active circuit includes at least one transistor having an operating current density which is approximately 35% or less of the peak fT operating current density and/or the active circuit includes a multi-transistor bank disposed in at least two separate sections, each pair of sections spaced apart to provide improved thermal uniformity among the transistors without substantially increasing parasitic impedance among them for providing an improved lower phase noise output at said RF output terminal.

Abstract: A frequency multiplier for generating an output signal having a frequency N times the input signal, with N equal to or greater than 3, the frequency multiplier including a phase splitter circuit responsive to the input signal for generating N signals with phase differences, and a mixer circuit responsive to the N signals of the phasor circuit for providing an output signal having a frequency N times the input signal.

Abstract: A frequency multiplier for generating an output signal having a frequency N times the input signal, with N equal to or greater than 3, the frequency multiplier including a phase splitter circuit responsive to the input signal for generating N signals with phase differences, and a mixer circuit responsive to the N signals of the phasor circuit for providing an output signal having a frequency N times the input signal.

Abstract: A microwave oscillator is shown to include an oscillator having an output and a control port and a feedback circuit disposed between the output and the control port of the oscillator. The feedback circuit includes a modulated laser, having an input and an output, the input responsive to a portion of a signal from the output of the oscillator and a photo detector having an input and an output, the input of the photo detector responsive to a signal from the output of the modulated laser delayed by a predetermined amount of time. The feedback circuit further includes a detector having a first and a second input and an output, the first input of the detector responsive to a signal from the output of the photo detector, the second input responsive to a portion of the signal from the output of the oscillator shifted in phase to be in phase quadrature with the signal at the first input of the detector and the output of the detector coupled to the control port of the oscillator.

Abstract: A microwave oscillator is shown to include an oscillator having an output and a control port and a feedback circuit disposed between the output and the control port of the oscillator. The feedback circuit includes a modulated laser, having an input and an output, the input responsive to a portion of a signal from the output of the oscillator and a photo detector having an input and an output, the input of the photo detector responsive to a signal from the output of the modulated laser delayed by a predetermined amount of time. The feedback circuit further includes a detector having a first and a second input and an output, the first input of the detector responsive to a signal from the output of the photo detector, the second input responsive to a portion of the signal from the output of the oscillator shifted in phase to be in phase quadrature with the signal at the first input of the detector and the output of the detector coupled to the control port of the oscillator.

Abstract: A multiple feedback loop frequency synthesizer, having a first and a second feedback loop, each fed by one of a pair of reference frequency signals having a frequency separation equal to the desired frequency separation of the output signals provided by the synthesizer. The frequency of each of such reference frequency signals is greater than the desired frequency separation of the output signals provided by the synthesizer. With such arrangement, because the bandwidth of each of the feedback loops must be less than the frequency of the reference frequency signal fed to such loop, achievement of frequency separation less than the frequency of either one of the reference frequencies enables each of the feedback loops to have increased bandwidth and hence reduced frequency switching times and increased noise suppression.

Abstract: An improved microwave frequency signal source using a single frequency offset technique which increases the frequency range of an indirect frequency synthesizer to twice the highest operating frequency of the programmable digital frequency divider in the loop includes a voltage-controlled oscillator (VCO) operating within a predetermined microwave frequency band and phase-locked to a reference oscillator operating at a reference frequency below microwave frequencies. The offset loop signal is developed by heterodyning the voltage-controlled oscillator (VCO) output signal with a microwave signal whose frequency is located at the center of the predetermined microwave frequency band of the VCO to form a signal at an intermediate frequency (I.F.) within the frequency range of a programmable digital frequency divider.