Subharmonic image rejection and image enhancement mixer
US5517687A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1994 |
| Grant date | May 14, 1996 |
| Priority date | — |
| Expiry date | Feb 9, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D2200/0082
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A subharmonic image rejection and image enhancement mixer for mixing millimeter wavelength signals using a low conversion loss technique is described. A local oscillator frequency from an external source is fed to a first subharmonic mixer and through a phase shifter to a second subharmonic mixer. The phase shifter delays the local oscillator signal by (90.degree./n), where n is the multiple of the subharmonic mixers and is greater than 1. The first and second subharmonic mixers mix the local oscillator frequency with an input signal, which includes a desired frequency and an image frequency, to produce an intermediate frequency having a desired component and an image component at a select phase. A 0.degree.-90.degree. hybrid separates and terminates the image component of the intermediate frequency. The input port that feeds the input signal to each subharmonic mixer is dimensioned so as to provide a virtual image short termination or an image short termination to a self-generated image signal from each subharmonic mixer, thereby decreasing the conversion loss of the frequency mixer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.