The present disclosure relates to a phase-locked loop (PLL) based on a charge-sharing locking technique, capable of both fractional-N and integer-N operation. The PLL comprises a voltage pre-setting stage; an oscillator: a shared capacitive load; and a switching network configured for selectively connecting the voltage pre-setting stage to the shared capacitive load during a voltage pre-setting stage for applying an expectant voltage to the capacitive load. The switching network is being further configured for selectively connecting the capacitive load to the oscillator during a charge-sharing locking stage for correcting a phase error in response to a difference between the expected voltage of the capacitor and the voltage of the oscillator. Frequency-tracking and waveform-learning stages are also provided for maintaining PVT (process, voltage, temperature) robustness and for suppressing fractional-N spur, respectively.

Apparatus and methods for generating multiple oscillating signals. An example circuit generally includes a first voltage-controlled oscillator (VCO) circuit and a second VCO circuit having a differential bias input coupled to a differential output of the first VCO circuit. At least one of the first VCO circuit or the second VCO circuit generally includes: a pair of cross-coupled transistors comprising a first transistor and a second transistor, a first inductive element coupled between a first node and the drain of the first transistor, a second inductive element coupled between the first node and the drain of the second transistor, a third transistor having a drain coupled to the drain of the first transistor and having a source coupled to a second node, and a fourth transistor having a drain coupled to the drain of the second transistor and having a source coupled to the second node.

An integrated frequency quadruplet consists of a pair of balanced frequency doublers that are driven in phase quadrature using a hybrid coupler. This approach results, effectively, in a “unilateral” multiplier that presents a match to the input-driving source, irrespective of the impedance of the doubler stages. The present invention applies this architecture to implement an integrated frequency quadruplet with output frequency of 160 GHz using quasi-vertical GaAs varactors fabricated on thin silicon support membranes. The quadruplet has a balanced circuit architecture that addresses degradation issues often arising from impedance mis-matches between multiplier stages. A unique quasi-vertical diode process is used to implement the quadruplet, resulting in an integrated drop-in chip module that incorporates 18 varactors, matching networks and beamleads for mounting. The chip is tailored to fit a multiplier waveguide housing resulting in high reproducibility and consistency in manufacture and performance.

A quadrature voltage-controlled oscillator circuit with phase shift includes two voltage-controlled oscillators with the same structure, wherein the two voltage-controlled oscillators are connected to each other through input and output ports, and the two voltage-controlled oscillators respectively include a cross-coupled oscillating circuit, an injection locking circuit, a resonant circuit and a voltage-controlled current source circuit which are electrically connected to each other; and signals are injected through the injection locking circuit and coupled with the oscillating circuit, so as to output a quadrature signal. An oscillator is enabled to operate stably in one mode by means of a simple circuit structure, and a good phase shift can be provided for the resonant circuit in a lower frequency band; and meanwhile, a tuning range of the oscillator is improved without increasing phase noise.

Techniques are described related to digital radio control, partitioning, and operation. The various techniques described herein enable high-frequency local oscillator signal generation and frequency multiplication using radio-frequency (RF) digital to analog converters (RFDACs). The use of these components and others described throughout this disclosure allow for the realization of various improvements. For example, digital, analog, and hybrid beamforming control are implemented and the newly-enabled digital radio architecture partitioning enables radio components to be pushed to the radio head, allowing for the omission of high frequency cables and/or connectors.

Quadrature oscillator circuitry, comprising: a first differential oscillator circuit having differential output nodes and configured to generate a first pair of differential oscillator signals at those output nodes, respectively; a second differential oscillator circuit having differential output nodes and configured to generate a second pair of differential oscillator signals at those output nodes, respectively; and a cross-coupling circuit connected to cross-couple the first and second differential oscillator circuits. The cross-coupling circuit may comprise a pair of cross-coupled transistors.

Techniques are described related to digital radio control, partitioning, and operation. The various techniques described herein enable high-frequency local oscillator signal generation and frequency multiplication using radio-frequency (RF) digital to analog converters (RFDACs). The use of these components and others described throughout this disclosure allow for the realization of various improvements. For example, digital, analog, and hybrid beamforming control are implemented and the newly-enabled digital radio architecture partitioning enables radio components to be pushed to the radio head, allowing for the omission of high frequency cables and/or connectors.

Quadrature oscillator circuitry, comprising: a first differential oscillator circuit having differential output nodes and configured to generate a first pair of differential oscillator signals at those output nodes, respectively; a second differential oscillator circuit having differential output nodes and configured to generate a second pair of differential oscillator signals at those output nodes, respectively; and a cross-coupling circuit connected to cross-couple the first and second differential oscillator circuits. The cross-coupling circuit may comprise a pair of cross-coupled transistors.

Quadrature oscillator circuitry, comprising: a first differential oscillator circuit having differential output nodes and configured to generate a first pair of differential oscillator signals at those output nodes, respectively; a second differential oscillator circuit having differential output nodes and configured to generate a second pair of differential oscillator signals at those output nodes, respectively; and a cross-coupling circuit connected to cross-couple the first and second differential oscillator circuits. The cross-coupling circuit may comprise a pair of cross-coupled transistors.

Quadrature oscillator circuitry, comprising: a first differential oscillator circuit having differential output nodes and configured to generate a first pair of differential oscillator signals at those output nodes, respectively; a second differential oscillator circuit having differential output nodes and configured to generate a second pair of differential oscillator signals at those output nodes, respectively; and a cross-coupling circuit connected to cross-couple the first and second differential oscillator circuits. The cross-coupling circuit may comprise a pair of cross-coupled transistors.