Wide band digital phase locked loop (PLL) with a half-frequency output
First Claim
1. An apparatus implementing a digital phase locked loop comprising:
- an automatic gain control arranged to apply gain to an input signal in order to produce a gain controlled signal;
a 90°
phase shifter arranged to provide a 90°
phase shifted version of the gain controlled signal;
a phase detector driven by the gain controlled signal, by the 90°
phase shifted version of the gain controlled signal, and by sinusoidal and co-sinusoidal signals;
a loop filter arranged to integrate an output of the phase detector and to provide servo equalization for the phase-locked loop; and
, a digital dual frequency oscillator having a fundamental frequency controlled by an output signal from the loop filter in order to generate the sinusoidal and co-sinusoidal signals.
1 Assignment
0 Petitions
Accused Products
Abstract
A digital phase locked loop includes an automatic gain control that applies a gain to an input signal in order to provide a gain controlled signal. A 90 ° phase shifter applies a 90 ° phase shift to the gain controlled signal in order to provide a 90 ° phase shifted version of the gain controlled signal. A phase detector is driven by the gain controlled signal, by the 90 ° phase shifted version of the gain controlled signal, and by sinusoidal and co-sinusoidal signals. A loop filter integrates an output of the phase detector and provide servo equalization for the phase-locked loop. A digital dual frequency oscillator has a fundamental frequency controlled by an output signal from the loop filter. Also, the digital dual frequency oscillator generates the sinusoidal and co-sinusoidal signals.
66 Citations
39 Claims
-
1. An apparatus implementing a digital phase locked loop comprising:
-
an automatic gain control arranged to apply gain to an input signal in order to produce a gain controlled signal;
a 90°
phase shifter arranged to provide a 90°
phase shifted version of the gain controlled signal;
a phase detector driven by the gain controlled signal, by the 90°
phase shifted version of the gain controlled signal, and by sinusoidal and co-sinusoidal signals;
a loop filter arranged to integrate an output of the phase detector and to provide servo equalization for the phase-locked loop; and
,a digital dual frequency oscillator having a fundamental frequency controlled by an output signal from the loop filter in order to generate the sinusoidal and co-sinusoidal signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A method implemented by a phase locked loop comprising:
-
applying a gain to an input signal to produce an in-phase gain controlled signal, wherein the input signal has a frequency 2f0;
shifting the in-phase gain controlled signal by 90°
to produce a quadrature gain controlled signal;
detecting a phase difference dependent upon the in-phase gain controlled signal, the quadrature gain controlled signal, and first and second output signals; and
,producing the first and second output signals and a third output signal in response to the phase difference, wherein the third output signal has a frequency f0, and wherein the each of the first and second output frequencies has a frequency 2f0. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
-
-
32. A method of driving a gyro comprising:
-
shifting an in-phase signal by 90°
to produce a quadrature signal, wherein the in-phase signal is derived from a first output of the gyro, wherein the in-phase signal has a frequency 2f0, and wherein the quadrature signal has a frequency 2f0;
detecting a phase difference dependent upon the in-phase signal, the quadrature signal, and first and second output signals;
producing the first and second output signals and a third output signal in response to the phase difference, wherein the third output signal has a frequency f0, and wherein the each of the first and second frequencies has a frequency 2f0;
producing an angular rate indicating signal based upon a second output of the gyro and the first and second output signals; and
,driving the gyro in response to the third output signal. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39)
-
Specification