Self-oscillating mixer circuits, and FMCW radar
US5280290A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 14, 1992 |
| Grant date | Jan 18, 1994 |
| Priority date | — |
| Expiry date | Oct 14, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03C3/245
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A simple self-oscillating mixer circuit is provided, suitable for forming with an antenna (21) the complete front end of an inexpensive short-range FMCW radar. A modulating signal (40), e.g. from a sweep generator (44), is applied to a control terminal (14) to sweep the RF output (R) of the self-oscillating mixer SOM (10). A cancellation circuit (6 to 9) is connected between the control terminal (14) and an IF output line (13) to remove a corresponding modulation (41) which occurs on the IF line (13) and so to generate a substantially demodulated IF output signal (I). Advantageously a grounded-source MESFET in a feed-back network forms the SOM (10) and has the IF output line (13) taken from its gate. In this case the IF modulation (41) is inverted with respect to the modulating signal (40), and so the cancellation is achieved by adding the modulating signal (40) to the modulated IF output signal (41), e.g. via a resistor network 6 to 8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.