Injection locking oscillator with phase rotation capability

A system, comprising:

• an oscillator;
• and
• a first injection circuit coupled to the oscillator, wherein the first injection circuit comprises:
• a first multiplexer configured to receive multiple clock signals, select a first clock signal and a second clock signal from among the multiple clock signals, and output the first clock signal and the second clock signal;
• a first injection branch coupled to a first node, wherein the first injection branch is configured to receive the first clock signal from the first multiplexer and generate a first injection current based on the first clock signal;
• and
• a second injection branch coupled to the first node, wherein the second injection branch is configured to receive the second clock signal from the first multiplexer and generate a second injection current based on the second clock signal, and wherein the first injection current and the second injection current are combined at the first node;
• and
• a second injection circuit coupled to the oscillator, wherein the second injection circuit comprises:
• a second multiplexer configured to receive the multiple clock signals, select a third clock signal and a fourth clock signal from among the multiple clock signals, and output the third clock signal and the fourth clock signal, wherein the first clock signal, the second clock signal, the third clock signal, and the fourth clock signal are phase offset from one another;
• a third injection branch coupled to a second node, wherein the third injection branch is configured to receive the third clock signal from the second multiplexer and generate a third injection current based on the third clock signal;
• and
• a fourth injection branch coupled to the second node, wherein the fourth injection branch is configured to receive the fourth clock signal from the second multiplexer and generate a fourth injection current based on the fourth signal, and wherein the third injection current and the fourth injection current are combined at the second node.

A system, comprising:

• an oscillator;
• and
• an injection circuit coupled to the oscillator, wherein the injection circuit comprises:
• a first injection branch coupled to a node, wherein the first injection branch comprises:
• a first input circuit configured to receive a first clock signal and generate a first injection current based on the first clock signal;
• and
• a first strength control circuit coupled between the node and the first input circuit;
• and
• a second injection branch coupled to the node, wherein the second injection branch comprises:
• a second input circuit configured to receive a second clock signal and generate a second injection current based on the second clock signal;
• and
• a second strength control circuit coupled between the node and the second input circuit, wherein the first injection current and the second injection current are combined at the node to obtain a combined injection current, and wherein the first strength control circuit and the second strength control circuit are configured to adjust the first injection current and the second injection current, respectively, in opposite directions to adjust a phase of the combined injection current.