Dual-loop linearizer for FM-CW radar
US6114987A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 29, 1999 |
| Grant date | Sep 5, 2000 |
| Priority date | — |
| Expiry date | May 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/23
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for generating a linear frequency sweep while also improving the phase noise characteristics of a microwave or millimeter wave signal source. The invention uses two phase lock loops. The first phase lock loop uses a linear frequency source to linearize a relatively low frequency VCO (typically around 100 MHz). The first phase lock loop has a bandwidth that is only wide enough to pass the radar modulation waveform with minimal distortion. The first phase lock loop includes a phase detector, narrow band loop filter, low noise HF VCO and a divide by M counter. The second phase lock loop is used to lock a millimeter wave VCO to the lower frequency of the low frequency VCO in the first loop. The low phase noise characteristics of this low frequency VCO are effectively impressed upon a microwave or millimeter wave, low noise high frequency VCO. The low noise high frequency VCO output from the first phase lock loop becomes the reference input for the second phase lock loop, which includes a phase detector, wide band loop filter, millimeter wave (MMW) VCO a local oscillator, mixer, amplifier/filter and a divide by R counter. The MMW VCO output is the FM-CW radar transmi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.