[Amps] ARF1505

[Steve Thompson]

On Saturday 21 May 2005 04:44, Will Matney wrote:
> What the spec sheet says is this;
>
> "The ARF1505 is an RF power transistor designed for off-line 300V operation
> in very high power scientific, commercial, medical and industrial RF power
> generator and amplifier applications up to 40 MHz."
>
> On the webpage it says they are for;
>
> "INDUSTRIAL, SCIENTIFIC, MEDICAL (ISM) & HF COMMUNICATIONS"
>
> Notice it saying amplifier applications. On the linear portion, that would
> really be where you set the bias at. It should run fine at class A or AB
> service. Also, being for HF communications would have to be linear........ 

It might not be quite that simple. If I remember the app. note for the 50MHz 
'linear', the IMD is always poor because the devices don't have a linear 
transfer characterisitic - the power in/out curve is banana shaped, without a 
straight line anywhere.

I've also seen instability where devices intended to be driven hard into 
saturation for 'brute power' delivery are biassed for linear operation.

Steve