Group delay measurement apparatus and method

US9933467B1 · kind B1 · utility

Assignee

• Guzik Technical Enterprises · US

Inventors

• Anatoli B. Stein · Atherton, US
• Alexander Taratorin · Palo Alto, US
• Semen P. Volfbeyn · Milpitas, US

Key dates

• Filing date: Sep 16, 2016
• Grant date: Apr 3, 2018
• Expiry date: Sep 16, 2036

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/31725
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Measurement of group delay for a device under test (DUT). A test signal includes (i) a low frequency sine wave fLF, (ii) sine wave harmonics at a high frequency fHF, (iii) L pairs of sideband components at frequencies k·fHF±2·fLF, where k odd, and M pairs of sideband components at frequencies k·fHF±fLF, where k is even. At DUT output, (i) phase ϕLF at frequency fLF is measured, (ii) both sideband phase ϕright(k) at frequencies k·fHF+2·fLF and phase ϕleft(k) at frequencies k·fHF−2·fLF for odd k, are measured, and (iii) both sideband phases ϕright(k) at frequencies k·fHF+fLF and ϕleft(k) at frequencies k·fHF−fLF for even k, are measured. Group delay τk at frequencies k·FHF, are determined from: τk=(ϕright(k)−ϕleft(k)−4·ϕL)/(4·fLF) for k odd, and τk=(ϕright(k)−ϕleft(k)−2·ϕL)/(2·fLF) for k even.