PLL DEVICE

• US 20150028957A1
• Filed: 07/02/2014
• Published: 01/29/2015
• Est. Priority Date: 07/24/2013
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Suzuki, Toshihide, Matsumura, Hiroshi
• Application Number:
  US14/322,531
• Publication Number:
  US 20150028957A1
• Time in Patent Office: Days
• US Class Current: 331/25
• CPC Class Codes: H03L 7/0992 comprising a counter or a frequency divider
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence

Abstract

A PLL device includes a variable frequency oscillator and a frequency divider section. The variable frequency oscillator varies an oscillation frequency in response to a control signal including information on a phase difference between a reference signal and a frequency division signal and oscillates an output signal obtained by multiplying a frequency of the reference signal. The frequency divider section frequency-divides the output signal to generate the frequency division signal. An injection locked frequency divider is arranged in the frequency divider section, the control signal is input to the injection locked frequency divider, and the operation frequency of the injection locked frequency divider is controlled by the control signal.

Claims

1. A PLL device comprising:

a variable frequency oscillator configured to vary an oscillation frequency in response to a control signal including information on a phase difference between a reference signal and a frequency division signal and oscillate an output signal obtained by multiplying a frequency of the reference signal; and

a frequency divider section configured to frequency-divide the output signal to generate the frequency division signal, wherein

an injection locked frequency divider is arranged in the frequency divider section, the control signal is input to the injection locked frequency divider, and an operation frequency of the injection locked frequency divider is controlled by the control signal.

2. The PLL device according to claim 1, wherein the injection locked frequency divider oscillates at an operation frequency at which a ratio of an output frequency change per unit voltage of the variable frequency oscillator to an operation frequency change per unit voltage of the injection locked frequency divider is in a proportional relation to a frequency division ratio of the injection locked frequency divider.

3. The PLL device according to claim 1, wherein the frequency divider section includes a plurality of frequency dividers connected in multiple stages, and the injection locked frequency divider is arranged in a frequency divider in the first stage which directly receives the output signal of the variable frequency oscillator.

4. The PLL device according to claim 1, wherein the injection locked frequency divider includes:

an oscillation section configured to oscillate a differential output, the oscillation section including;

an inductor section having a plurality of inductors connected in series;

a variable capacitance section connected in parallel to the inductor section and configured to vary a capacitance value by inputting of the control signal; and

a negative resistance section connected in parallel to the inductor section and configured to generate a negative resistance; and

a switch element configured to switch and frequency-divide the differential output in response to an input level.

5. The PLL device according to claim 4, wherein the inductor section includes a first inductor and a second inductor, and one end of the first inductor and one end of the second inductor are connected to a power supply line, wherein

the variable capacitance section includes a first diode and a second diode, a cathode of the first diode and a cathode of the second diode are connected to each other, and the control signal is input to a common cathode connection point, wherein

the negative resistance section includes an N-channel type first transistor and an N-channel type second transistor which are cross-coupled, a drain of the first transistor is connected to another end of the first inductor, an anode of the first diode, a gate of the second transistor, and a first differential output terminal, and a drain of the second transistor is connected to another end of the second inductor, an anode of the second diode, a gate of the first transistor, and a second differential output terminal, and wherein

the switch element is an N-channel type third transistor, a drain of the third transistor is connected to sources of the first transistor and the second transistor, a source of the third transistor is connected to GND, and the output signal of the variable frequency oscillator is input to a gate of the third transistor.

6. The PLL device according to claim 4, wherein the inductor section includes a first inductor and a second inductor, and one end of the first inductor and one end of the second inductor are connected to the power supply line, wherein

the variable capacitance section includes a first diode and a second diode, a cathode of the first diode and a cathode of the second diode are connected to each other, and the control signal is input to a common cathode connection point, wherein

the negative resistance section includes an N-channel type first transistor and an N-channel type second transistor which are cross-coupled, wherein

the switch element is an N-channel type third transistor, wherein

a drain of the first transistor is connected to another end of the first inductor, an anode of the first diode, a gate of the second transistor, a first differential output terminal, and a source of the third transistor, wherein

a drain of the second transistor is connected to another end of the second inductor, an anode of the second diode, a gate of the first transistor, a second differential output terminal, and a drain of the third transistor, and wherein

sources of the first transistor and the second transistor are connected to GND, and the output signal of the variable frequency oscillator is input to a gate of the third transistor.

7. The PLL device according to claim 4, wherein the inductor section includes a first inductor and a second inductor, and one end of the first inductor and one end of the second inductor are connected to the power supply line, wherein

the variable capacitance section includes a first diode and a second diode, a cathode of the first diode and a cathode of the second diode are connected to each other, and the control signal is input to a common cathode connection point, wherein

the negative resistance section includes an N-channel type first transistor and an N-channel type second transistor which are cross-coupled, wherein

the switch element includes an N-channel type third transistor and an N-channel type fourth transistor, wherein

a drain of the first transistor is connected to another end of the first inductor, an anode of the first diode, a gate of the second transistor, a first differential output terminal, and a drain of the third transistor, wherein

a drain of the second transistor is connected to another end of the second inductor, an anode of the second diode, a gate of the first transistor, a second differential output terminal, and a drain of the fourth transistor, and wherein

sources of the first to fourth transistors are connected to GND, one differential output signal of the variable frequency oscillator is input to a gate of the third transistor, and another differential output signal of the variable frequency oscillator is input to a gate of the fourth transistor.