Evaluation of LO Power Leveling Techniques Used for Remote Mixing

Author: Sudarshan ‘CV’ Chakravarty
Publication: AMTA 2010
Copyright Owner: NSI-MI Technologies

Operating microwave receivers with remote mixers in a system requires the LO power to be flat over broadband frequencies. In large systems, this is difficult to attain due to long RF cables. Most systems require significant engineering to ensure the LO power level to the mixer is adequate. To help understand the problem, commonly used techniques have been evaluated while recommending a particular approach.

Operating over a small fundamental frequency range with harmonic mixing has the advantage of lower RF cable insertion loss but results in high mixer conversion loss. Using negative slope equalizers and amplifiers, RF cable slope and attenuation can be sufficiently combated. However, this requires extensive system engineering and customization to match cable losses, thereby making it expensive. The approach is also designed to only work with a certain set of RF cables.

A more viable approach includes independently controlling the attenuators and amplifiers for the signal and reference channels which can be configured to provide optimal LO power to the respective mixer. A simple setup file configures components in each channel to adapt to any set of RF cables. Positive experimental results of implementing this technique in different configurations are presented.


1125 Satellite Blvd., Suite 100
Suwanee, GA 30024-4629 USA

+1 678 475 8300
+1 678 542 2601

Los Angeles

19730 Magellan Drive
Torrance, CA 90502-1104 USA

+1 310 525 7000
+1 310 525 7100


Unit 51 Harley Road
Sheffield, S11 9SE UK

+44 7493 235224


Newport, RI Finding your local time... 43 Days www.amta2020.org

Latest Tweets

This site is using cookies for analytical purposes and to provide a better user experience. Read our Privacy Policy for more information.