# 20 dB Attenuator for GSM Field Meter

R

#### [email protected]

Jan 1, 1970
0
I have a digital field strength meter covering the 800MHz to 2.5GHz
range To it is connected, via SMA cable, a log periodic antenna. The
available reading only goes to 1999 uW/m2. I would like to place a
20dB attentuator in-line with the antenna to increase this by a factor
of 100.

Can anyone please suggest what circuit or components to use? Is
something like this all I need?

Can I assume the meter's input impedance is 50 Ohms?

Richard Jones

J

#### Jasen Betts

Jan 1, 1970
0
I have a digital field strength meter covering the 800MHz to 2.5GHz
range To it is connected, via SMA cable, a log periodic antenna. The
available reading only goes to 1999 uW/m2. I would like to place a
20dB attentuator in-line with the antenna to increase this by a factor
of 100.

Can anyone please suggest what circuit or components to use? Is
something like this all I need?

If only it was that simple! at 800 to 2.5Ghz layout is going to be critical if
you want a flat response over that range.

At the first online supplier I checked 3GHz attenuators seem to start at
around $40 for upto 10dB, 20dB is twice as much. Can I assume the meter's input impedance is 50 Ohms? If it's not it'll probably written somewhere near the input TV uses 75 ohms, but most other things are 50 ohms. U #### [email protected] Jan 1, 1970 0 I have a digital field strength meter covering the 800MHz to 2.5GHz range To it is connected, via SMA cable, a log periodic antenna. The available reading only goes to 1999 uW/m2. I would like to place a 20dB attentuator in-line with the antenna to increase this by a factor of 100. How is the actual measurement instrument protected against direct radiation penetration ? Sure, you can insert various attenuators along the line, but if the signal source will penetrate directly in to the equipment from the air, you are in trouble. F #### Fred Abse Jan 1, 1970 0 I have a digital field strength meter covering the 800MHz to 2.5GHz range To it is connected, via SMA cable, a log periodic antenna. The available reading only goes to 1999 uW/m2. I would like to place a 20dB attentuator in-line with the antenna to increase this by a factor of 100. Can anyone please suggest what circuit or components to use? Is something like this all I need? http://www.radio-electronics.com/in...gn/attenuators/attenuator-resistor-values.php Can I assume the meter's input impedance is 50 Ohms? SMA are 50 ohms, hence yes. Use a Pi-section attenuator, theoretical values are 61.11 ohms, 247.5 ohms, 61.11 ohms. Good luck with getting it to stay resistive up to 2.5GHz. L #### Lund-Nielsen, Jorgen Jan 1, 1970 0 Am 04.04.2013 12:29, schrieb Jasen Betts: At the first online supplier I checked 3GHz attenuators seem to start at around$40 for upto 10dB, 20dB is twice as much.

Naaa,

Minicircuits DC-6GHz SMA Attenuatos, regardless of the AttenFactor
are around 12\$/Piece..!

have a look:

<www.minicircuits.com/pdfs/VAT-20.pdf>

Jorgen

D

Jan 1, 1970
0
I have a digital field strength meter covering the 800MHz to 2.5GHz
range To it is connected, via SMA cable, a log periodic antenna. The
available reading only goes to 1999 uW/m2. I would like to place a
20dB attentuator in-line with the antenna to increase this by a factor
of 100.

Can anyone please suggest what circuit or components to use? Is
something like this all I need?

Can I assume the meter's input impedance is 50 Ohms?

Richard Jones

http://www.minicircuits.com/pdfs/K1-LAT+.pdf

http://www.surplussales.com/rf/RFAtten-4.html

A really nice one!
<http://www.ebay.com/itm/NICE-MCL-BW...803?pt=LH_DefaultDomain_0&hash=item3cd07e44ab>

Woo-Woo EMF Attenuator
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