Phase locked loop arrangement, transmitter and receiver and method for adjusting the phase between oscillator signals

A phase locked loop arrangement for a beamforming system, comprising:

• a plurality of phase-adjustable phase locked loops, each configured to provide a respective oscillator signal and each comprising:
• a frequency divider to provide a frequency divided signal based on the oscillator signal;
• a phase comparator configured to output a respective control signal in response to a detection of a phase deviation between a common reference signal and the frequency divided signal;
• an adjustable charge pump arrangement having a loop filter, and a charge pump with an adjustment input, wherein the charge pump is connected to the loop filter to inject an adjustable charge pump current into the loop filter;
• and
• a constant current source configured to inject a first predetermined charge current into the loop filter;
• wherein the adjustable charge pump arrangement is connected to the phase comparator to provide a voltage control signal to an oscillator of the phase-adjustable phase locked loop in response to the control signal and to generate a phase deviation between the oscillator signal of the phase-adjustable phase locked loop and an oscillator signal of at least one other phase-adjustable phase locked loop of the plurality of phase-adjustable phase locked loops, based on the charge pump comprising a current-mirror circuit that adjusts the adjustable charge pump current output by the charge pump into the loop filter in dependence on the value of an adjustment signal applied to the adjustment input;
• and
• wherein the current-mirror circuit comprises a reference current side configured to receive a fixed reference current and generate an adjustable reference current responsive to the value of the adjustment signal, the adjustable reference current mirrored to an output side of the current-mirror circuit and output as the adjustable charge pump current.