US 7,656,205 B2Granted

Dual-injection locked frequency dividing circuit

AssigneeNational Taiwan University

InventorsYi-Jan Emery Chen, Tang-Nian Luo

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Abstract

A dual-injection locked frequency dividing circuit is proposed, which is designed for integration to a gigahertz signal processing circuit system for providing a frequency dividing function to gigahertz signals. The proposed circuit architecture is characterized by the provision of a dual-injection interface module on the input end for dividing the input signal into two parts for use as two injection signals, wherein the first injection signal is rendered in the form of a voltage signal and injected through a direct injection manner to the internal oscillation circuitry, while the second injection signal is rendered in the form of an electrical current and injected through a resonant circuit to the internal oscillation circuitry. This feature allow the proposed frequency dividing circuit to have broad frequency locking range and low power consumption.

Claims23

Dependent claims

A dual-injection locked frequency dividing circuit having an input/output interface including a signal input port and a pair of differential output ports including a positive differential output port and a negative differential output port, for providing a frequency dividing function to an input signal at the signal input port;

the dual-injection locked frequency dividing circuit comprising:
a dual-injection interface module, which is used to bifurcate the input signal into at least two signals respectively serving as a first injection signal and a second injection signal;
wherein the first injection signal is injected in a switched manner to both a first node and a second node where the first node is connected to the positive differential output port and the second node is connected to the negative differential output port, while the second injection signal is injected to a third node;
a first cross-switching circuit module, for providing a cross-switching function to the first injection signal injected by the dual-injection interface module across the first node and the second node;
a second cross-switching circuit module, for providing an inversed cross-switching function to the first injection signal injected by the dual-injection interface module across the first node and the second node;
a first resonant circuit module, which is connected between the first node and the second node for providing a resonant effect to the first injection signal injected by the dual-injection interface module;
and
a second resonant circuit module, which is connected between the third node and a grounding point for providing a resonant effect to the second injection signal injected by the dual-injection interface module.

5 more elements

the dual-injection locked frequency dividing circuit comprising:
a dual-injection interface module, which includes an NMOS-based switching element, and which is used to bifurcate the input signal into at least two signals respectively serving as a first injection signal and a second injection signal;
wherein the first injection signal is injected in a switched manner via the NMOS-based switching element to both a first node and a second node where the first node is connected to the positive differential output port and the second node is connected to the negative differential output port, while the second injection signal is injected to a third node;
a PMOS-based cross-switching circuit module, for providing a cross-switching function to the first injection signal injected by the dual-injection interface module across the first node and the second node;
an NMOS-based cross-switching circuit module, for providing an inversed cross-switching function to the first injection signal injected by the dual-injection interface module across the first node and the second node;
a first resonant circuit module, which is connected between the first node and the second node for providing a resonant effect to the first injection signal injected by the dual-injection interface module;
and
a second resonant circuit module, which is connected between the third node and a grounding point for providing a resonant effect to the second injection signal injected by the dual-injection interface module.

5 more elements

Dependencies are inferred from the claim text.