Apparatus, system, and method of local oscillator (LO) generator
For example, a Local Oscillator (LO) generator may include a plurality of frequency sources configured to provide a respective plurality of frequency source signals according to a first frequency; and an injection-locked frequency divider configured to provide an LO signal having a second frequency. In one example, the second frequency may be based on the first frequency divided by a factor n. For example, the factor n may be an odd integer greater than one. For example, the injection-locked frequency divider may include a plurality of injection paths to inject the plurality of frequency source signals into an injection-locked Ring Oscillator (RO).
1 . An apparatus comprising:
a Local Oscillator (LO) generator configured to generate an LO signal, the LO generator comprising:
a plurality of frequency sources configured to provide a respective plurality of frequency source signals according to a first frequency; and
an injection-locked frequency divider configured to provide the LO signal having a second frequency, wherein the second frequency is based on the first frequency divided by n, wherein n is an odd integer greater than 1, wherein the injection-locked frequency divider comprises a plurality of injection paths to inject the plurality of frequency source signals into an injection-locked Ring Oscillator (RO), wherein a frequency source signal of the plurality of frequency source signals has a first phase noise, and wherein the LO signal has a second phase noise lower than the first phase noise.
2 . The apparatus of claim 1 , wherein the plurality of frequency sources comprises a first frequency source to provide a first frequency source signal according to the first frequency, and a second frequency source to provide a second frequency source signal according to the first frequency, wherein the injection-locked frequency divider comprises a first injection path to inject the first frequency source signal into a first inverter stage of the injection-locked RO, and a second injection path to inject the second frequency source signal into a second inverter stage of the injection-locked RO.
3 . The apparatus of claim 1 , wherein a count of injection paths in the plurality of injection paths is equal to a count of frequency sources in the plurality of frequency sources.
4 . The apparatus of claim 3 , wherein the plurality of injection paths are configured to respectively inject the plurality of frequency source signals into the injection-locked RO.
5 . The apparatus of claim 1 , wherein a count of injection paths in the plurality of injection paths is greater than a count of frequency sources in the plurality of frequency sources.
6 . The apparatus of claim 5 , wherein two or more injection paths are configured to inject a same frequency source signal into the injection-locked RO.
7 . The apparatus of claim 1 , wherein an injection path of the plurality of injection paths comprises a plurality of injection-locking transistors connected in series to an inverter stage of the injection-locked RO, wherein the plurality of injection-locking transistors is controllable according to a frequency source signal of the plurality of frequency source signals.
8 . The apparatus of claim 1 , wherein the plurality of frequency sources are uncorrelated.
9 . The apparatus of claim 1 , wherein the second phase noise is lower than the first phase noise by a factor of 10 log (m), wherein m denotes a count of frequency sources in the plurality of frequency sources.
10 . The apparatus of claim 1 , wherein n=3.
11 . The apparatus of claim 1 comprising a frequency multiplier configured to multiply the second frequency of the LO signal by a factor greater than one.
12 . The apparatus of claim 1 , wherein a frequency source of the plurality of frequency sources comprises a Digital Phase Locked Loop (DPLL).
13 . The apparatus of claim 1 comprising a Radio Frequency (RF) chain configured to process an RF signal based on the LO signal.
14 . An apparatus comprising:
a Local Oscillator (LO) generator configured to generate an LO signal, the LO generator comprising:
a plurality of frequency sources configured to provide a respective plurality of frequency source signals according to a first frequency; and
an injection-locked frequency divider configured to provide the LO signal having a second frequency, wherein the second frequency is based on the first frequency divided by n, wherein n is an odd integer greater than 1, wherein the injection-locked frequency divider comprises a plurality of injection paths to inject the plurality of frequency source signals into an injection-locked Ring Oscillator (RO); and
a controller configured to control a phase of at least one frequency source signal of the plurality of frequency source signals based on an amplitude of the LO signal.
15 . The apparatus of claim 14 , wherein the controller is configured to control a phase difference between at least first and second frequency source signals of the plurality of frequency source signals based on the amplitude of the LO signal.
16 . The apparatus of claim 14 , wherein the plurality of frequency sources are uncorrelated.
17 . A device comprising:
a Local Oscillator (LO) generator configured to generate an LO signal, the LO generator comprising:
a plurality of frequency sources configured to provide a respective plurality of frequency source signals according to a first frequency; and
an injection-locked frequency divider configured to provide the LO signal having a second frequency, wherein the second frequency is based on the first frequency divided by n, wherein n is an odd integer greater than 1, wherein the injection-locked frequency divider comprises a plurality of injection paths to inject the plurality of frequency source signals into an injection-locked Ring Oscillator (RO);
a controller configured to control a phase of at least one frequency source signal of the plurality of frequency source signals based on an amplitude of the LO signal;
a Radio Frequency (RF) chain configured to process an RF signal based on the LO signal;
an antenna to communicate the RF signal; and
a processor configured to process information based on the RF signal.
18 . The device of claim 17 , wherein the plurality of frequency sources comprises a first frequency source to provide a first frequency source signal according to the first frequency, and a second frequency source to provide a second frequency source signal according to the first frequency, wherein the injection-locked frequency divider comprises a first injection path to inject the first frequency source signal into a first inverter stage of the injection-locked RO, and a second injection path to inject the second frequency source signal into a second inverter stage of the injection-locked RO.
19 . The device of claim 17 comprising a wireless communication device, wherein the processor is configured to process wireless communication signals communicated by the RF chain.
20 . The device of claim 17 comprising a radar device, wherein the processor is configured to generate radar information based on radar signals communicated by the RF chain.