Noise parameter measurement system
OwnerChristos Tsironisinventor
Life of this patent
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Abstract
A noise parameter test setup allows accurately measuring the four noise parameters (Fmin, Rn, Γopt) of microwave transistors over a wide frequency range using two wideband directional couplers, instead of SPDT switches, to merge the s-parameter (signal) measurement path and the noise measurement path, avoiding thus the uncertainty of the switching repeatability of the SPDT switches and improving the measurement accuracy. Calibration of the system is the same as when using switches. Additional power control precautions of the VNA sources are necessary to avoid injecting large signal power into the sensitive noise receiver during s-parameter measurements and jamming the weak noise power during noise measurement.
Claims9
A computer controlled noise parameter measuring system comprising,
- a noise signal measurement path and a scattering (s-) parameter measurement path,
- whereby both paths are permanently joined using directional couplers;
- said noise measurement path comprising a cascade of calibrated noise source, input directional coupler, input bias network, impedance tuner, device under test (DUT) mounted in a test fixture, output bias network, output directional coupler and noise receiver,
- and whereby the s-parameter measurement path comprises a vector network analyzer (VNA) and shares the couplers, bias networks, test fixture and DUT with the noise measurement path, whereby the s-parameter path joins the noise path through the coupling ports of the couplers.
Dependencies are inferred from the claim text.