A system for generating a radio frequency signal phase-locked to a reference signal. Such a system includes a rotary travelling wave oscillator including a conductive ring and a plurality of sustaining amplifying cells electrically connected to the ring; a programmable multiplexer device designed to electrically connect an input port of the system to an amplifying cell that can be selected from the cells of the plurality. The system is designed so that the oscillator generates the locked radio frequency signal when the reference signal is injected at the input port of the system. A phase difference between the radio frequency signal and the reference signal is a function of the amplifying cell to which the input port is electrically connected via the programming of the multiplexer device.

A circuit, integrated circuit, and radar system implementing a highly coupled inductor design for a multi-core oscillator is provided. An example circuit may include a plurality of inductors, each inductor including: a first inductor portion and a second inductor portion electrically connected in series. In some embodiments, for each inductor, the first inductor portion may be magnetically coupled to a first or second inductor portion of a first coupling inductor of the plurality of inductors, and the second inductor portion may be magnetically coupled to a first or second inductor portion of a second coupling inductor of the plurality of inductors, where the first coupling inductor and the second coupling inductor are different inductors.

Apparatus and methods for frequency tuning of rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, distributed quantized tuning is used to tune a frequency of the RTWO. The RTWO includes a plurality of segments distributed around the RTWO's ring, and the segments include tuning capacitors and other circuitry. The distributed quantized frequency tuning is used to control the tuning capacitors in the RTWO's segments using separately controllable code values, thereby enhancing the RTWO's frequency step size or resolution. Moreover, in configurations including multiple RTWO rings that are locked to one another to reduce phase noise, the distributed quantized frequency tuning can be used to separately set the tuning capacitors across multiple RTWO rings that are coupled to one another.

A voltage-controlled oscillator includes a first transistor, a second transistor, a first center-tapped inductor, two first varactors, a second center-tapped inductor and two second varactors. The first and second transistors cooperatively forma cross-connected pair. The first center-tapped inductor and the first varactors cooperatively form a first LC tank. The second center-tapped inductor and the second varactors cooperatively forma second LC tank. The cross-connected pair is connected between the first and second LC tanks. The first and second center-tapped inductors are mutual-inductively coupled to each other. An oscillation signal pair is provided between the first LC tank and the cross-connected pair.

A down converter, including first and second biasing circuits, mixer, and transformer coupled to receive amplifier output signal. The first and second biasing circuits each include a biasing transistor and a first and second node, respectively. Mixer includes first and second transistors coupled to first node and third and fourth transistors coupled to second node. The second and fourth transistors are coupled to a third node. The first and third transistors are coupled to a fourth node. Mixer also includes a first resistor coupled to the fourth node and a supply voltage node and a second resistor coupled to the third node and a supply voltage node. Transformer includes a primary winding coupled to receive the amplifier output signal and to a supply voltage and a secondary winding coupled to mixer and first biasing circuit at first node and coupled to mixer and second biasing circuit at second node.

An oscillator includes a first output node and a second output node. There is a tank circuit coupled between the first output node and the second output node. There is a first transistor having a first node, a second node coupled to a current source, and a control node coupled to the second output node. There is a second transistor having a first node, a second node coupled to the current source, and a control node coupled to the first output node. There is a first inductor coupled in series between the first node of the first transistor and the first output node. There is a second inductor coupled in series between the first node of the second transistor and the second output node.

A phased array transmitter includes a plurality of vector modulators, an in-phase/quadrature (I/Q) signal generator, and a multiphase generator. The output phases of the plurality of vector modulators, and hence the direction of transmission of the phased array transmitter, are set and controlled by adjusting both the magnitude ratios of I/Q signal pairs generated by the I/Q signal generator and applied to I and Q inputs of the plurality of vector modulators and phases of a plurality of local oscillator (LO) signal phases generated by the multiphase generator and applied to LO inputs of the plurality of vector modulators. Setting and controlling the output phases of the vector modulators by varying both the magnitude ratios of the I/Q signal pairs and the phases of the LO signal phases allows the output phases of the plurality of vector modulators to be more precisely set and controlled than if the output phases were to be set and controlled only through the LO paths or only through the I/Q signal paths of the plurality of vector modulators.

A signal generator and an associated resonator circuit are provided. The signal generator includes the resonator circuit and a core circuit. The resonator circuit further includes a first inductor (L1), a second inductor (L2), a plurality of capacitors and a switching circuit. The first inductor (L1) has a first terminal (N1) and a third terminal (N3), and the second inductor (L2) has a second terminal (N2) and a fourth terminal (N4). The switching circuit includes a first switch (S1), a second switch (S2), a third switch (S3) and a fourth switch (S4). The core circuit further includes a first inner circuit, a first outer circuit, a second inner circuit, and a second outer circuit. Configurations of these switches are adjustable and resonance caused between these terminals is changed accordingly.

An oscillator includes a first output node and a second output node. There is a tank circuit coupled between the first output node and the second output node. There is a first transistor having a first node, a second node coupled to a current source, and a control node coupled to the second output node. There is a second transistor having a first node, a second node coupled to the current source, and a control node coupled to the first output node. There is a first inductor coupled in series between the first node of the first transistor and the first output node. There is a second inductor coupled in series between the first node of the second transistor and the second output node.

Systems and methods providing wireless synchronization of wave arrays may include an antenna that receives a wireless injection signal and another antenna that radiates a locked wave signal corresponding to the injection signal. In some embodiments, these systems may also provide a low noise amplifier, voltage controlled oscillator (VCO), buffer amplifier(s), phase shifter, and/or multi-stage amplifier. In some embodiments, the injection signal may be provided on an even harmonic, and the intended transmission frequency signal is on an odd harmonic of the locked signal. The substrate thickness may be designed to radiate electromagnetic waves in odd harmonics of the locked signal. In yet another embodiment, polarization of a receiving antenna may be orthogonal to a transmitter antenna.