WIDEBAND OSCILLATION CIRCUIT

• US 20110187469A1
• Filed: 02/01/2011
• Published: 08/04/2011
• Est. Priority Date: 02/02/2010
• Status: Active Grant

• Current Assignee: Semiconductor Technology Academic Research Center
• Original Assignee: Semiconductor Technology Academic Research Center
• Inventors: Hara, Shoichi, Okada, Kenichi
• Granted Patent: US 8,248,172 B2
• Time in Patent Office: Days
• US Class Current: 331/117.FE
• CPC Class Codes: H03B 5/12 active element in amplifier being semiconductor device H03B5/14 takes precedence
• CPC Class Codes: H03L 7/24 using a reference signal directly applied to the generator

Abstract

A wideband oscillation circuit outputting oscillation signals (divided signals) of continuous frequencies is disclosed and the wideband oscillation circuit includes an oscillator that outputs an oscillation signal, a filter that filters the oscillation signal output from the oscillator and outputs an injection locked signal, and an injection locked frequency divider that performs a free-run operation and outputs a divided signal of the oscillation signal while its oscillating operation is regulated by the injection locked signal, the division ratio of which varies in accordance with a control signal, wherein the filter generates the injection locked signal by controlling the passing characteristic that caused the oscillation signal to pass with respect to time in accordance with a filter control signal locked with the divided signal.

Claims

1. A wideband oscillation circuit comprising:

an oscillator that outputs an oscillation signal;

a filter that receives and filters the oscillation signal output from the oscillator and outputs an injection locked signal; and

an injection locked frequency divider that performs a free-run operation and outputs a divided signal of the oscillation signal while the oscillating operation thereof is being controlled by the injection locked signal, the division ratio of which varies in accordance with a control signal, wherein

the filter controls the passing characteristic that causes the oscillation signal to pass with respect to time in accordance with a filter control signal locked with the divided signal to generate the injection locked signal.

2. The wideband oscillation circuit according to claim 1, wherein

the injection locked frequency divider outputs a divided signal in a division ratio of a number other than an integer.

3. The wideband oscillation circuit according to claim 1, wherein

the oscillator can vary the frequency of the oscillation signal in a predetermined range.

4. The wideband oscillation circuit according to claim 1, wherein

the injection locked frequency divider is a ring oscillator type.

5. The wideband oscillation circuit according to claim 4, wherein

in the injection locked frequency divider, the division ratio is varied by varying a bias voltage of an amplifier configuring the ring oscillator type injection locked frequency divider in accordance with the control signal.

6. The wideband oscillation circuit according to claim 4, wherein

the injection locked frequency divider is a ring oscillator type having a differential two-stage configuration.

7. The wideband oscillation circuit according to claim 6, wherein

the filter control signal uses an output signal in one of the stages of the ring oscillator type injection locked frequency divider to connect an output in the other stage of the ring oscillator type injection locked frequency divider in accordance with the injection locked signal.

8. The wideband oscillation circuit according to claim 1, wherein

the filter comprises:

an input terminal to which the oscillation signal is input and an output terminal from which the injection locked signal is output;

a passing switch that controls the passing characteristic that causes the oscillation signal to pass; and

a connection switch that controls whether or not to connect the output terminal of the passing switch to a predetermined potential, and

the passing switch enters a state where the passing switch suppresses the oscillation signal from passing and at the same time, the connection switch enters a connected state in accordance with the filter control signal.

9. The wideband oscillation circuit according to claim 8, wherein

the passing switch and the connection switch are configured by two transistors and the divided signal output from the injection locked frequency divider is applied to gates of the two transistors.

10. The wideband oscillation circuit according to claim 8, wherein

the passing switch and the connection switch are configured by two transistors and the gates of the two transistors are connected to a predetermined potential via a resistor and at the same time, the divided signal is applied via a capacitor.