Embedded phase noise measurement system
AssigneeUniversity of Florida Research Foundation, Inc.
InventorsWilliam Richard Eisenstadt, Jae Shin Kim
Life of this patent
Estimating the term…
Abstract
Phase noise detection systems for a device under test (DUT) are provided that can be embedded within a chip. According to one embodiment, the embedded phase noise detection system can include an active delay line cell, a phase shifter, and a phase detector. The active delay line and phase shifter separately receive the output signal of the DUT. The phase detector can include a double-balanced mixer followed by an active RC filter. The double-balanced mixer receives, as input, the outputs from the active delay line and phase shifter and can produce different dc voltages proportional to the difference from the input phase quadrature. An auto-adjustment circuit can also be included to help the input signal from the phase shifter to the mixer maintain quadrature.
Claims17
An embedded phase noise measurement system comprising:
- an analog delay line comprising a plurality of cascaded active amplifier stages;
- an analog phase shifter;
- and
- a mixer for comparing phase information of signals output from the analog delay line and the analog phase shifter and outputting a dc signal proportional to the phase difference between the signals output from the analog delay line signal and the signals output from the phase shifter,
- wherein the analog phase shifter comprises a plurality of cascaded variable delay cell stages, wherein each variable delay cell stage comprises:
- a variable resistance delay cell circuit;
- and
- a source follower circuit at an output of the variable resistance delay cell circuit.
An embedded phase noise measurement system comprising:
- an analog delay line comprising a plurality of cascaded active amplifier stages;
- an analog phase shifter;
- and
- a mixer for comparing phase information of signals output from the analog delay line and the analog phase shifter and outputting a dc signal proportional to the phase difference between the signals output from the analog delay line signal and the signals output from the phase shifter,
- wherein the mixer comprises:
- a double balanced mixer with an active RC filter;
- and
- a first capacitor shunt connected between a first output of the double balanced mixer and a first input of the active RC filter, and a second capacitor shunt connected between a second output of the double balanced mixer and a second input of the active RC filter, the first capacitor and the second capacitor being connected to a virtual ground.
An embedded phase noise measurement system comprising:
- an analog delay line comprising a plurality of cascaded active amplifier stages:
- an analog phase shifter;
- and
- a mixer for comparing phase information of signals output from the analog delay line and the analog phase shifter and outputting a dc signal proportional to the phase difference between the signals output from the analog delay line signal and the signals output from the phase shifter,
- wherein the mixer comprises a double balanced mixer with an active RC filter, wherein the RC filter comprises:
- an operational amplifier having a differential input stage, an output stage, and a common mode feedback circuit;
- and
- a compensation mechanism for expanding the operational amplifier's bandwidth.
An embedded phase noise measurement system comprising:
- an analog delay line comprising a plurality of cascaded active amplifier stages;
- an analog phase shifter;
- a mixer for comparing phase information of signals output from the analog delay line and the analog phase shifter and outputting a dc signal proportional to the phase difference between the signals output front the analog delay line signal and the signals output from the chase shifter;
- and
- an auto-adjustment circuit comprising a comparator and a phase shifter control unit for automatic control of phase quadrature for the analog phase shifter based on the output of the mixer.
Dependencies are inferred from the claim text.