p1 db? - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues - primarily having to spend time purging garbage posts from the board. At some point I might start the RF Cafe Forums again if the phpBB software gets better at filtering spam.

Below are the old forum threads, including responses to the original posts.

-- Amateur Radio
-- Anecdotes, Gripes & Humor
-- Antennas
-- CAE, CAD, & Software
-- Circuits & Components
-- Employment & Interviews

-- Miscellany
-- Swap Shop
-- Systems
-- Test & Measurement
-- Webmaster

Peter_Bateman

Post subject: p1 db?

Posted: Tue Nov 22, 2005 9:49 pm

output p1 I know how to measure Op1dB on a vna using power sweep but am trying to figure it out using Sig gen and power meter. (wich one is more accurate?) I am thinking you reference the output power on the PM then increase the input pwr by 10 and wait till i only get 9db but that seem's to me to be a hard way.
Thanks in advance for any help and input.

Kirt Blattenberger

Post subject:

Posted: Wed Nov 23, 2005 12:22 am

Site Admin

Joined: Sun Aug 03, 2003 2:02 pm
Posts: 476
Location: Erie, PA

Greetings Peter_Bateman:

Both the VNA and the signal generator + power meter methods should produce the same results provided the test is carried out properly. Be certain to obtain a reference gain for the device under test (DUT) while it is operating well within the linear operating region, and with the input reference signal at least 20 dB above the noise floor - ideally filtered to the BW of the system operational BW. Then, as you state, find the output power at which the gain of the DUT is 1 dB less than the linear gain. Making the measurement with the signal generator + power meter really does not take long if you are only testing a few devices.

_________________
- Kirt Blattenberger :smt024

RF Cafe Progenitor & Webmaster

Posted 11/12/2012

Webmaster:

Kirt Blattenberger,

BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website: AirplanesAndRockets.com

My Daughter's Website: EquineKingdom