Fano interferometric phase detector based phase locked loop
A fano interferometric phase detector comprising a dielectric core with a top surface and a bottom surface, wherein the top surface and the bottom surface are substantially parallel. The phase detector includes a main transmission line on the top surface and a first quarter wavelength stub on the top surface electrically coupled to the main transmission line. The phase detector includes a second quarter wavelength stub on the top surface electrically coupled to the main transmission line, and a port line on the top surface, wherein the port line is an extension above the main transmission line. The phase detector further includes a ground plane on the bottom surface, wherein the dielectric core insulates the ground plane from the main transmission line, the first quarter wavelength stub, the second quarter wavelength stub, and the port line.
1 . A fano interferometric phase detector comprising:
a dielectric core with a top surface and a bottom surface, wherein the top surface and the bottom surface are substantially parallel;
a main transmission line on the top surface;
a first quarter wavelength stub on the top surface electrically coupled to the main transmission line;
a second quarter wavelength stub on the top surface electrically coupled to the main transmission line;
a port line on the top surface, wherein the port line is an extension above the main transmission line; and
a ground plane on the bottom surface, wherein the dielectric core insulates the ground plane from the main transmission line, the first quarter wavelength stub, the second quarter wavelength stub, and the port line.
2 . The fano interferometric phase detector of claim 1 , the first quarter wavelength stub, the second quarter wavelength stub are open circuit stubs that are spaced and extending away from the main transmission line.
3 . The fano interferometric phase detector of claim 1 , wherein a shape of the first quarter wavelength stub or the second quarter wavelength stub of the fano interferometric phase detector has one of straight-edge shape, polygonal shape, circular shape, elliptical shape, or any combination thereof.
4 . The fano interferometric phase detector of claim 1 , wherein the dielectric core comprises one or more dielectric materials.
5 . The fano interferometric phase detector of claim 1 , wherein the main transmission line comprises a first port on a first end and a second port on a second end, and wherein the first and second ports are input ports.
6 . The fano interferometric phase detector of claim 1 , wherein the port line comprises a port on an end, and wherein the port is an output port.
7 . The fano interferometric phase detector of claim 1 , wherein the ground plane substantially overlaps the main transmission line, the first quarter wavelength stub, the second quarter wavelength stub, and the port line.
8 . A fano interferometric phase detector comprising:
a dielectric core with a top surface and a bottom surface, wherein the top surface and the bottom surface are substantially parallel;
a main transmission line on the top surface;
a first quarter wavelength stub on the top surface electrically coupled to the main transmission line;
a second quarter wavelength stub on the top surface electrically coupled to the main transmission line;
a first port line on the top surface and coupled to the main transmission line and the first quarter wavelength stub;
a second port line on the top surface and coupled to the main transmission line and the second quarter wavelength stub; and
a ground plane on the bottom surface, wherein the dielectric core insulates the ground plane from the main transmission line, the first quarter wavelength stub, the second quarter wavelength stub, and the first and second port lines.
9 . The fano interferometric phase detector of claim 8 , wherein the first quarter wavelength stub, the second quarter wavelength stub are open circuit stubs that are substantially spaced and extending away from the main transmission line.
10 . The fano interferometric phase detector of claim 8 , wherein a shape of the first quarter wavelength stub or the second quarter wavelength stub of the fano interferometric phase detector has one of straight-edge shape, polygonal shape, circular shape, elliptical shape, or any combination thereof.
11 . The fano interferometric phase detector of claim 8 , wherein the dielectric core comprises one or more dielectric materials.
12 . The fano interferometric phase detector of claim 8 , wherein the main transmission line comprises:
a first input port on a first end of the main transmission line; and
a second input port on a second end of the main transmission line, wherein the first end and the second end are opposite to one another.
13 . The fano interferometric phase detector of claim 8 , wherein the first and second port lines are first and second output ports.
14 . The fano interferometric phase detector of claim 8 , wherein the ground plane substantially overlaps the main transmission line, the first quarter wavelength stub, the second quarter wavelength stub, and the first and second port lines.
15 . The fano interferometric phase detector of claim 8 , wherein the first port line is aligned with the first quarter wavelength stub, and wherein the second port line is aligned with the second quarter wavelength stub.
16 . A phase locked loop comprising:
a fano interferometric phase detector configured to receive an input signal and a feedback signal, wherein the fano interferometric phase detector outputs a phase error signal depending on a phase difference of the input signal and the feedback signal;
a loop filter to receive the phase error signal from the fano interferometric phase detector, perform a filtering operation on the phase error signal, and produce a fine control value based on the phase difference between the input signal and the feedback signal; and
a voltage controlled oscillator configured to receive the fine control value from the loop filter and produce a voltage control oscillator (VCO) output with its phase adjusted based on the fine control value, wherein the VCO output is served as a phase locked loop output, wherein the phase locked loop output is a feedback signal to be fed into the fano interferometric phase detector, and wherein the feedback signal is aligned with the input signal when the feedback signal and the input signal are in-phase and their frequencies are equal or close to each other within an acceptable tolerance limit.
17 . The phase locked loop of claim 16 , wherein the fano interferometric phase detector comprises:
a main transmission line, wherein the input signal is applied to a first end of the main transmission line and the feedback signal is applied to a second end of the main transmission line;
a first quarter wavelength stub;
a second quarter wavelength stub, wherein the first quarter wavelength stub and the second quarter wavelength stub are electrically coupled to the main transmission line, wherein the first quarter wavelength stub and the second quarter wavelength stub are open-circuit stubs extending away from the main transmission line, and wherein the first quarter wavelength stub and the second quarter wavelength stub are spaced along the main transmission line;
one or more port lines, wherein an individual port line of the one or more port lines is an extension above the main transmission line, wherein the phase error signal is output from a port line of the one or more port lines, and wherein the main transmission line, the first quarter wavelength stub, the second quarter wavelength stub, and the one or more port lines are etched on a top surface of a dielectric core; and
a ground plane is etched on a bottom surface of the dielectric core.
18 . The phase locked loop of claim 16 , wherein the phase error signal is rectified using a rectifier or fed into an AC-to-DC charge pump to be charge pumped before being filtered by the loop filter.
19 . The phase locked loop of claim 16 , wherein the phase locked loop is configured to synchronize with the input signal.
20 . The phase locked loop of claim 16 , wherein the VCO is controlled using a coarse control value from a frequency controller to tune an operational frequency of the VCO.