Method and apparatus for performance characterization of satellite transponders
AssigneeITT Manufacturing Enterprises, Inc.
InventorEugene Estinto
Life of this patent
Estimating the term…
Abstract
Method and apparatus for performance characterization of Ka band transponders wherein measurements are made. A wideband modulated data signal is used to test the response of the Ka band transponder. A periodic test pattern, preferably a pseudo-noise (PN) sequence, modulated on a carrier, is transmitted to an onboard satellite transponder which then retransmits the signal to a receiver where a down converter is used to output inphase and quadrature phase baseband signals which are digitized and used for measuring one or more of the following: Magnitude and phase response AM/AM and AM/PM Phase noise Bit error rate Data asymmetry I/Q channel imbalance.
Claims7
A method of measuring distortion in satellite RF transponders operated at or near saturation comprising,
- transmitting a wideband periodic RF signal having a known periodic pattern to said transponders on said satellite, said wideband periodic RF signal being generated by modulating the output of a PN sequence generator,
- receiving wideband periodic RF signals at said transponder which retransmits the wideband periodic RF signals,
- downconverting said relayed said relayed wideband periodic RF signals to baseband inphase (I) and quadrature phase (Q) signal components,
- converting said I and Q signal components to I and Q digital signal components and storing said I and Q digital signal component in computer memory, and
- performing one or more of the following measurements on the stored I and Q digital signal components:
- Magnitude and phase response
- AM/AM and AM/PM
- Phase noise
- Bit error rate
- Data asymmetry
- I/Q channel imbalance.
An apparatus for measuring distortion in Ka band RF transponders which are onboard an orbiting satellite and operated at or near saturation comprising,
- means for transmitting a wideband RF signal having a known periodic pattern to said transponder on said orbiting satellite, a PN sequence generator said wideband RF signal being generated by modulating the output of said PN sequence generator,
- means for receiving wideband RF signals at said transponder which retransmits the wideband RF signals,
- means for downconverting the relayed wideband RF signals to baseband inphase (I) and quadrature phase (Q) signal components,
- means for converting said I and Q signal components to I and Q digital signal components and storing said I and Q digital signal component in a computer memory, and
- means for performing one or more of the following measurements on the stored I and Q digital signal components:
- Magnitude and phase response
- AM/AM and AM/PM
- Phase noise
- Bit error rate
- Data asymmetry
- I/Q channel imbalance.
A method of measuring distortion in an RF network comprising,
- transmitting a wideband periodic RF signal having a known periodic pattern modulated thereon to said wideband RF network, said known periodic pattern being generated by a PN sequence generator,
- passing said wideband RF signals having a known periodic pattern through said network and outputting a measurement signal,
- down converting and digitizing said measurement signal to inphase (I) and quadrature (Q) digital signal components and storing said I and Q digital signal component in computer memory, and
- performing one or more of the following measurements on the stored measurement I and Q digital signal components:
- Magnitude and phase response
- AM/AM and AM/PM
- Phase noise
- Bit error rate
- Data asymmetry
- I/Q channel imbalance.
Apparatus for measuring distortion in an RF network comprising,
- means for transmitting a wideband RF signal having a known periodic pattern to said RF network, said known periodic pattern being generated by a PN sequence generator,
- means for passing said wideband RF signals through said network and outputting a measurement signal,
- means for converting and digitizing said measurement signal to inphase (I) and quadrature (Q) digital signal components and storing said I and Q digital signal component in computer memory, and
- means for performing one or more of the following measurements on the stored measurement I and Q digital signal components:
- Magnitude and phase response
- AM/AM and AM/PM
- Phase noise
- Bit error rate
- Data asymmetry
- I/Q channel imbalance.
A method for performance characterization of Ka band transponders comprising passing a wideband RF signal through the Ka band transponder, said wideband RF signal having a periodic test pattern modulated thereon, and downconverting output of said transponder to inphase (I) AND QUADRATURE (Q) phase baseband signals digitizing said I and Q signals and measuring one or more of the following characteristics:
- Magnitude and phase response
- AM/AM and AM/PM
- Phase noise
- Bit error rate
- Data asymmetry
- I/Q channel imbalance.
Apparatus for performance characterization of Ka band transponders comprising means for passing a wideband RF signal to a K band transponder, said wideband RF signal including a periodic test pattern modulated thereon,
- means for downconverting outputs of said Ka band transponder to inphase (I) and quadrature (Q) phase band signals, means for digitizing said I and Q signals and means for measuring one or more of the following characteristics from said I and Q signals:
- Magnitude and phase response
- AM/AM and AM/PM
- Phase noise
- Bit error rate
- Data asymmetry
- I/Q channel imbalance.
Dependencies are inferred from the claim text.