discrete class E at 433

[biff44]

application not nesg260234

I am trying to do a discrete class E amp to put out 1W at 433 MHz for very low cost (<$1). Anyone have a schematic, or a device choice to suggest?

Rich

 

[vfone]

bfg591 schematic

Try this one from Maxim, which works from DC up to 900MHz.
http://www.datasheetcatalog.org/datasheet/maxim/MAX2601-MAX2602.pdf

The schematic of the application note do not specify the power class, but replace T2 with an inductor, and tune the values of the series and parallel caps to place the amplifier in Class-E.

The price is a little bit higher ~$1.8, but I think is hard to make this circuit below one buck.

 

[biff44]

class e power + maxim

Thanks. I did not realize that maxim sold such devices! Unfortunately, it looks like it is going to be too expensive for me (>$3 @ 1000 pcs). I am looking at nxp and nec bipolar transistors, which look like they are 1/3 the price of similar GaAs based devices. I need something that is <$0.50 in 100K pcs.

 

[yendori]

class e schematic

I used the BFQ32S for a class E @ 450ish MHz Pout=33dBm
I can't remember the cost, but it was much less than $3.

**broken link removed**

 

[biff44]

bfg591 datasheet

That must have been a while ago, as the BFQ32 went obsolete in 2003. I found something similar to it, thought. I am trying the following:
BFG21W
BFG591
BFG480W
NE664
NESG260234
NESG270034

 

[vfone]

bfg591 amp

BFG480W has 20dBm (0.1W) output.
BFG21W has 26dBm (0.4W) output
BFG591 has 1W, but supplied at 12V DC.
NE664 has 26dBm (0.4W) output.
NESG260234 is fine, but the price is almost the same as MAX2601.
If I have to choose I would go for Maxim device. NEC components are difficult to get exactly when you need.

 

[biff44]

amp bfg591

IF I want a $3 part, I can just use a Skyworks mmic and be done with it. I am looking at those specific parts because they are the closest parts that Digikey had in-stock, and they can handle between .25 and .7 A of current. I am not sure what the conversion is between current capacity and class E output power--I guess I will fool around with them and figure it out. I can get by with as little as 800 mw. And yes, I realize that in class A or AB they put out much less power.

I'll get some of the maxim chips too, jsut to see how they work.

 

[yendori]

bfg591 circuit

Yeah it was 10 years ago.

It was for UAV target drones.

That was the good old days