Handheld vecor network analyzer (VNA) operating at a high frequency by mixing LO and RF signals having offset odd harmonics
US5977779A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 24, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Oct 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A vector network analyzer (VNA) has a first harmonic generator multiplying an RF signal by an odd number M1 to produce incident and reflected test signals received at inputs of mixers providing IF signals. A second harmonic generator multiplies an LO signal by an odd number M2 offset by 2 from M1 to provide signals to additional inputs of the mixers providing IF signals. With the harmonic generators providing odd harmonics separated by 2, a single filter removes remaining harmonics from IF signals provided from each mixer. Each harmonic generator includes two step recovery diodes (SRDs) with opposing ends connecting the signal path to ground, the SRDs functioning to cancel even harmonics. A first coupler provides the output of the first harmonic generator to the mixers, the first coupler having a minimal size enabling its output power to increase with frequency. With the first harmonic generator having power decreasing with frequency and the first coupler having power increasing with frequency, the VNA test signal will have a substantially flat power vs. frequency response. Additional couplers having a minimal size provide the incident and reflected test signals to the mixers. With…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.