High Frequency Measurements Web Page
Douglas C. Smith

 Address:  P. O. Box 1457, Los Gatos, CA 95031
 TEL:      800-323-3956/408-356-4186
 FAX:      408-358-3799
 Mobile:   408-858-4528
 URL:      www.dsmith.org
 Email:    doug@dsmith.org

Hardware Links

This page contains links to interesting sites. I am familiar with this equipment on this page and consider it to be of  high quality. I have no financial interest in any products or companies listed below. I just like the products and find them useful in design verification and EMC investigations.

Barth Electronics
1300 Wyoming St., Boulder City, NV 89005
TEL:   702-293-1576
FAX:   702-293-7024
Email: jonbarth@aol.com

Barth Electronics specializes in high frequency measurement gear. The item shown in the picture is a 180° Combiner. It subtracts the two inputs to produce a single output. It is useful in making the Balanced Coaxial Probe that I describe in my seminars. A Balanced Coaxial Probe is the best way to make high frequency differential measurements. This combiner has a common mode rejection ratio of over 40 dB from 100 kHz to 1 GHz! There is nothing like it on the market. Barth Electronics has lots of other very wide bandwidth hardware including T-pad attenuators, ESD simulator calibration targets, and many other goodies with bandwidths to 20 GHz and beyond.

Click on the picture to link to the Barth Electronics Website.

Fischer Custom Communications
TEL:   310-891-0635
FAX:   310-891-0644
Email: sales@fischercc.com

The picture above shows a pair of matched F-33-1 current probes. These probes are matched within 1% to 2% with each other and have a flat frequency response from a few MHz to about 300 MHz. The absolute amplitude specification is +/- 2 dB. A matched pair of current probes is useful in many measurement situations. For instance, in ESD measurements for troubleshooting equipment designs, a matched set of current probes can be used to quickly track down how ESD currents are flowing in the equipment cables. A matched set of probes is also useful for measuring the relative phase between two common mode currents on system cables. In my seminars, I show how this information can be used to help pinpoint modes of EMC problems than cannot be seen by amplitude measurements alone. For more information on this topic you can also see my  paper, "Current Probes, More Useful Than You Think," presented at the 1998 IEEE EMC Symposium. Fischer also manufactures a Balanced Coaxial Probe that makes excellent differential measurements to 500 MHz without the probe resonance found with probes that have a capacitive input impedance.

Click on the picture to link to the Fischer Custom Communications Website.

Credence Technologies
3601-A Caldwell Drive, Soquel, CA 95073
TEL:   831-459-7488
FAX:   831-427-3513
Email: info@credencetech.com

Credence Technologies has some of the most useful and interesting instrumentation for EMC and ESD that I have seen. I can't possibly describe in this space the capabilities of just the one product shown above, the EM Eye. I would suggest visiting their website by clicking on the picture. It's an EMC/ESD engineer's toy store!

Top of page

Questions or suggestions? Contact me at doug@dsmith.org
Copyright © 1999-2001 Douglas C. Smith