[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Re: how much power can the BasicTX output?

From: Jeffrey Lambert
Subject: Re: [Discuss-gnuradio] Re: how much power can the BasicTX output?
Date: Fri, 25 Jun 2010 23:19:06 -0400
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv: Gecko/20100512 Thunderbird/3.0.5

It is worth noting that your calculation of power is missing a divide by 2, since you specify a peak-to-peak voltage, and not a peak voltage.  The equation for peak-to-peak voltage to power (given a 50 ohm impedance) is P (watts) = (.707*V/2)^2/50, which when I calculated yields something like .61 mw, so this is correct.

Also, as far as I am aware, the BasicTX board directly accessing the TX output of the AD9862 chip, so perhaps your best bet is to check the datasheet for this IC.  This should yield a power output versus frequency.  The alternative is to measure yourself, as you have done.  Remember, the datasheet is only a reference.  Actuall power levels can vary within a tolerance (which the datasheet should also provide) due to variations in gain and/or biasing, connector loss, transmission line loss, impedance mismatch, and so on.


On 6/25/2010 12:44 PM, William Cox wrote:
Sorry for the bump, but I'm confused about the output power of the BasicTX, especially in regards to 1 channel or both.
Any thoughts?

On Mon, Jun 21, 2010 at 10:46 AM, William Cox <address@hidden> wrote:
I'm getting conflicting info on how much power the BasicTX can transmit.
Ettus FAQ says, "Yes, the BasicTX will put out about 1mW up to about 50 MHz."
When I use "usrp_siggen.py" with full amplitude, my sineway has a peak-to-peak voltage of nearly 500mV -> (0.707*0.5V)^2/50ohm = 2.5mW

So, which should I go by? I'm trying to find an amplifier that will take my signal up to 200mW to go into a laser bias-T.

~Jeffrey Lambert,  K1VZX

reply via email to

[Prev in Thread] Current Thread [Next in Thread]