Frequency divider using an injection-locking-range enhancement technique

A method for improving a locking range of a injection-locked frequency divider comprising:

• receiving an input signal having a first frequency;
• generating an injection current and a DC current based in part on the input signal;
• generating an output signal having a second frequency in response to the injection current and the DC current, wherein the first frequency is a multiple of the second frequency;
• and
• adjusting the locking range by combining a bleed current with the injection current and the DC current.

An injection-locked frequency divider with injection enhancement, comprising:

• an input terminal;
• a first and a second different output terminals;
• a first and a second inductors;
• a first, a second, a third, and a fourth three-terminal devices, each having a control terminal, a first conducting terminal, and a second conducting terminal;
• and
• a resonator including the first and three second inductors connected electrically with physical capacitors, forming a differential inductor-capacitor (LC) tank, the resonator having a first and a second differential terminals and a third terminal, wherein
• the third terminal of the resonator is connected to a alternative-current (AC) ground;
• the first terminal of the resonator is connected to the first conducting terminal of the first three-terminal device, and coupled to the control terminal of the second three-terminal device;
• the second terminal of the resonator is connected to the first conducting terminal of the second three-terminal device, and coupled to the control terminal of the first three-terminal device;
• the first conducting terminal of the third three-terminal device is connected to both the second conducting terminal of the first three-terminal device and the second conducting terminal of the second three-terminal device;
• the first conducting terminal of the fourth three-terminal device is connected to both the second conducting terminal of the first three-terminal device and the second conducting terminal of the second three-terminal device;
• the third and the fourth three-terminal devices are connected in seriers between a a voltage supply (VDD) and a ground (GND) through the second conducting terminal of the third three-terminal device and the second conducting terminal of the fourth three-terminal device;
• the input terminal is connected to the control terminal of the third three terminal device and the control terminal of the fourth three terminal device;
• and
• the first and the second differential terminals of the resonator are the first and the second differential output terminals.

An injection-locked frequency divider with injection enhancement, comprising:

• an input terminal;
• a first and a second different output terminals;
• a first and a second inductors;
• a DC current source having a first conducting terminal and a second conducting terminal;
• a first, a second, and a third three-terminal devices, each having a control terminal, a first conducting terminal, and a second conducting terminal;
• and
• a resonator including the first and the second inductors connected electrically to a first and a second physical capacitors to form a differential inductor-capacitor (LC) tank, the resonator having a first and a second differential terminals and a third terminal, wherein
• the third terminal of the resonator is connected to an alternative-current (AC) ground;
• the first terminal of the resonator is connected to the first conducting terminal of the first three-terminal device and to the control terminal of the second three-terminal device;
• the second terminal of the resonator is connected to the first conducting terminal of the second three-terminal device and to the control terminal of the first three terminal device;
• the first conducting terminal of the third three-terminal device is connected to both the second conducting terminal of the first three-terminal device and the second conducting terminal of the second three-terminal device;
• the first conducting terminal of the DC current source is connected to both the second conducting terminal of the first three-terminal device and the second conducting terminal of the second three-terminal device;
• the DC current source and the third three-terminal device are connected in series between a voltage supply (VDD) and a ground (GND) through the second conducting terminal of the third three-terminal and the second conducting terminal of the DC current source;
• the input terminal is connected to the control terminal of the third three-terminal device;
• and
• the first and the second differential terminals of the resonator are utilized as the first and the second differential output terminals.