Injection-locked oscillator

An electronic oscillator circuit comprising:

• a tank circuit comprising an inductor and a capacitor, wherein the inductor and the capacitor each have a first terminal connected to a first side of the tank circuit and a second terminal connected to a second side of the tank circuit;
• a PMOS transistor;
• and
• an NMOS transistor;
• wherein the PMOS transistor is connected to the first side of the tank circuit;
• wherein the NMOS transistor is connected to the second side of the tank circuit;
• wherein the PMOS transistor is arranged such that it can act as a current source for the tank circuit;
• wherein the NMOS transistor is arranged such that it can act as a current sink for the tank circuit;
• wherein the PMOS transistor and the NMOS transistor are configured such that when the PMOS transistor and the NMOS transistor are in a first state, an injected current is introduced into the tank circuit from the PMOS transistor, and flows out of the circuit through the NMOS transistor;
• and
• when the first PMOS transistor and the NMOS transistor are in a second state, no current is injected into the tank circuit.

An electronic oscillator circuit comprising:

• a tank circuit comprising a first inductive winding and a capacitor;
• and
• an injection circuit comprising a second inductive winding and a current controller;
• wherein the injection circuit is not electrically connected to the tank circuit;
• wherein the current controller is configured such that when it is in a first state, an injected current flows from the current controller through the second inductive winding;
• wherein the current controller is configured such that when it is in a second state, no injected current flows through the second inductive winding;
• and
• wherein the first inductive winding and the second inductive winding are coupled such that the injected current in the second inductive winding of the injection circuit causes a corresponding injected current to be induced in the first inductive winding of the tank circuit;
• wherein the current controller is a PMOS transistor, arranged such that the source of the PMOS transistor is connected to a power supply rail or other supply of current;
• wherein a first terminal and a second terminal of the second inductive winding are connected to ground or other sink of current;
• and
• wherein a third terminal of the second inductive winding is connected to the drain of the PMOS transistor;
• wherein the third terminal is a centre tap of the second inductive winding.